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Wang M, Cheng Q, Wu Z, Fan L, Zeng L, Chen H. Multidimensional assessment of the biological effects of electronic cigarettes on lung bronchial epithelial cells. Sci Rep 2024; 14:4445. [PMID: 38396087 PMCID: PMC10891173 DOI: 10.1038/s41598-024-55140-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/20/2024] [Indexed: 02/25/2024] Open
Abstract
Cigarette smoke (CS) exposure is known to cause injury to respiratory tract epithelial cells and is a contributing factor in the development of chronic obstructive pulmonary disease and lung cancer. Electronic cigarettes (e-cigarettes) are gaining popularity as a potential substitute for conventional cigarettes due to their potential for aiding smoking cessation. However, the safety of e-cigarettes remains uncertain, and scientific evidence on this topic is still limited. In this study, we aimed to investigate the effects of CS and e-cigarette smoke (ECS) of different flavors on human lung bronchial epithelial cells. Real-time smoke exposure was carried out using an air-liquid interface system, and cell viability was assessed. RNA-Seq transcriptome analysis was performed to compare the differences between CS and ECS. The transcriptome analysis revealed a significantly higher number of differentially expressed genes in CS than in ECS. Moreover, the impact of mint-flavored e-cigarettes on cells was found to be greater than that of tobacco-flavored e-cigarettes, as evidenced by the greater number of differentially expressed genes. These findings provide a reference for future safety research on traditional cigarettes and e-cigarettes, particularly those of different flavors. The use of omics-scale methodologies has improved our ability to understand the biological effects of CS and ECS on human respiratory tract epithelial cells, which can aid in the development of novel approaches for smoking cessation and lung disease prevention.
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Affiliation(s)
- Meng Wang
- Hangzhou Center for Disease Control and Prevention, Hangzhou, 31021, China
| | - Qing Cheng
- Institute of Bioinformatics, Zhejiang University, Hangzhou, 310058, China
| | - Zehong Wu
- RELX Science Center, Shenzhen RELX Tech. Co. Ltd., Shenzhen, 518101, China
| | - Longjiang Fan
- Institute of Bioinformatics, Zhejiang University, Hangzhou, 310058, China
- School of Medicine, Hangzhou City University, Hangzhou, 310015, China
| | - Linghui Zeng
- School of Medicine, Hangzhou City University, Hangzhou, 310015, China
| | - Hongyu Chen
- Institute of Bioinformatics, Zhejiang University, Hangzhou, 310058, China.
- School of Medicine, Hangzhou City University, Hangzhou, 310015, China.
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2
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Mercier C, Pourchez J, Leclerc L, Forest V. In vitro toxicological evaluation of aerosols generated by a 4th generation vaping device using nicotine salts in an air-liquid interface system. Respir Res 2024; 25:75. [PMID: 38317149 PMCID: PMC10845662 DOI: 10.1186/s12931-024-02697-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/22/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Electronic cigarettes (EC) have gained popularity, especially among young people, with the introduction of fourth-generation devices based on e-liquids containing nicotine salts that promise a smoother vaping experience than freebase nicotine. However, the toxicological effects of nicotine salts are still largely unknown, and the chemical diversity of e-liquids limits the comparison between different studies to determine the contribution of each compound to the cytotoxicity of EC aerosols. Therefore, the aim of this study was to evaluate the toxicological profile of controlled composition e-liquid aerosols to accurately determine the effects of each ingredient based on exposure at the air-liquid interface. METHODS Human lung epithelial cells (A549) were exposed to undiluted aerosols of controlled composition e-liquids containing various ratios of propylene glycol (PG)/vegetable glycerin (VG) solvents, freebase nicotine, organic acids, nicotine salts, and flavoured commercial e-liquids. Exposure of 20 puffs was performed at the air-liquid interface following a standard vaping regimen. Toxicological outcomes, including cytotoxicity, inflammation, and oxidative stress, were assessed 24 h after exposure. RESULTS PG/VG aerosols elicited a strong cytotoxic response characterised by a 50% decrease in cell viability and a 200% increase in lactate dehydrogenase (LDH) production, but had no effects on inflammation and oxidative stress. These effects occurred only at a ratio of 70/30 PG/VG, suggesting that PG is the major contributor to aerosol cytotoxicity. Both freebase nicotine and organic acids had no greater effect on cell viability and LDH release than at a 70/30 PG/VG ratio, but significantly increased inflammation and oxidative stress. Interestingly, the protonated form of nicotine in salt showed a stronger proinflammatory effect than the freebase nicotine form, while benzoic acid-based nicotine salts also induced significant oxidative stress. Flavoured commercial e-liquids was found to be cytotoxic at a threshold dose of ≈ 330 µg/cm². CONCLUSION Our results showed that aerosols of e-liquids consisting only of PG/VG solvents can cause severe cytotoxicity depending on the concentration of PG, while nicotine salts elicit a stronger pro-inflammatory response than freebase nicotine. Overall, aerosols from fourth-generation devices can cause different toxicological effects, the nature of which depends on the chemical composition of the e-liquid.
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Affiliation(s)
- Clément Mercier
- Mines Saint-Etienne, Université Jean Monnet, INSERM, U1059 Sainbiose, Centre CIS, Saint-Etienne, 42023, France.
| | - Jérémie Pourchez
- Mines Saint-Etienne, Université Jean Monnet, INSERM, U1059 Sainbiose, Centre CIS, Saint-Etienne, 42023, France
| | - Lara Leclerc
- Mines Saint-Etienne, Université Jean Monnet, INSERM, U1059 Sainbiose, Centre CIS, Saint-Etienne, 42023, France
| | - Valérie Forest
- Mines Saint-Etienne, Université Jean Monnet, INSERM, U1059 Sainbiose, Centre CIS, Saint-Etienne, 42023, France
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3
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Tackett AP, Urman R, Barrington-Trimis J, Liu F, Hong H, Pentz MA, Islam TS, Eckel SP, Rebuli M, Leventhal A, Samet JM, Berhane K, McConnell R. Prospective study of e-cigarette use and respiratory symptoms in adolescents and young adults. Thorax 2024; 79:163-168. [PMID: 37582630 PMCID: PMC11062480 DOI: 10.1136/thorax-2022-218670] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 07/03/2023] [Indexed: 08/17/2023]
Abstract
RATIONALE Electronic cigarette (e-cigarette) aerosol contains volatile aldehydes, including flavourings and oxidant metals with known pulmonary toxicity. OBJECTIVES To evaluate the associations of e-cigarette use with symptoms of wheeze, bronchitic symptoms and shortness of breath (SOB) across 4 years of prospective data. METHODS Participants completed questionnaires on respiratory symptoms and past 30-day e-cigarette, cigarette and cannabis use in 2014 (wave 1; N=2094; mean age 17.3 years, SD=0.6 years). Follow-up information was collected in 2015 (wave 2; n=1609), 2017 (wave 3; n=1502) and 2018 (wave 4; n=1637) using online surveys. Mixed-effects logistic regression models evaluated associations of e-cigarette use with respiratory symptoms. MEASUREMENTS AND MAIN RESULTS Participants were mostly Hispanic white (51.8%) and evenly representative by sex (49.6% female; 50.4% male). Compared with never e-cigarette users, past 30-day e-cigarette users reported increased odds of wheeze (OR 1.81; 95% CI 1.28, 2.56), bronchitic symptoms (OR 2.06; 95% CI 1.58, 2.69) and SOB (OR 1.78; 95% CI 1.23, 2.57), adjusting for study wave, age, sex, race, lifetime asthma diagnosis and parental education. Effect estimates were attenuated (wheeze (OR 1.41; 95% CI 0.99, 2.01), bronchitic symptoms (OR 1.55; 95% CI 1.18, 2.05), SOB (OR 1.48; 95% CI 1.01, 2.18)), after adjusting additionally for current cigarette use, cannabis use and secondhand exposure to e-cigarettes/cigarettes/cannabis. CONCLUSIONS E-cigarette use in young adults was associated with respiratory symptoms, independent of combustible cannabis and cigarette exposures.
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Affiliation(s)
- Alayna P Tackett
- Department of Internal Medicine, Division of Medical Oncology, Center for Tobacco Research, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Robert Urman
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Jessica Barrington-Trimis
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Feifei Liu
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Hanna Hong
- Division of Pulmonology, Children's Hospital of Orange County, Orange, California, USA
| | - Mary Ann Pentz
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Talat S Islam
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Sandrah P Eckel
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Meghan Rebuli
- Department of Pediatrics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Adam Leventhal
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | - Jonathan M Samet
- Department of Epidemiology, Colorado School of Public Health, Aurora, Colorado, USA
| | - Kiros Berhane
- Department of Biostatistics, Columbia University, New York, New York, USA
| | - Rob McConnell
- Department of Population and Public Health Sciences, University of Southern California Keck School of Medicine, Los Angeles, California, USA
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4
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Effah F, Adragna J, Luglio D, Bailey A, Marczylo T, Gordon T. Toxicological assessment of E-cigarette flavored E-liquids aerosols using Calu-3 cells: A 3D lung model approach. Toxicology 2023; 500:153683. [PMID: 38013136 PMCID: PMC10826471 DOI: 10.1016/j.tox.2023.153683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/19/2023] [Accepted: 11/22/2023] [Indexed: 11/29/2023]
Abstract
Scientific progress and ethical considerations are increasingly shifting the toxicological focus from in vivo animal models to in vitro studies utilizing physiologically relevant cell cultures. Consequently, we evaluated and validated a three-dimensional (3D) model of the human lung using Calu-3 cells cultured at an air-liquid interface (ALI) for 28 days. Assessment of seven essential genes of differentiation and transepithelial electrical resistance (TEER) measurements, in conjunction with mucin (MUC5AC) staining, validated the model. We observed a time-dependent increase in TEER, genetic markers of mucus-producing cells (muc5ac, muc5b), basal cells (trp63), ciliated cells (foxj1), and tight junctions (tjp1). A decrease in basal cell marker krt5 levels was observed. Subsequently, we utilized this validated ALI-cultured Calu-3 model to investigate the adversity of the aerosols generated from three flavored electronic cigarette (EC) e-liquids: cinnamon, vanilla tobacco, and hazelnut. These aerosols were compared against traditional cigarette smoke (3R4F) to assess their relative toxicity. The aerosols generated from PG/VG vehicle control, hazelnut and cinnamon e-liquids, but not vanilla tobacco, significantly decreased TEER and increased lactate dehydrogenase (LDH) release compared to the incubator and air-only controls. Compared to 3R4F, there were no significant differences in TEER or LDH with the tested flavored EC aerosols other than vanilla tobacco. This starkly contrasted our expectations, given the common perception of e-liquids as a safer alternative to cigarettes. Our study suggests that these results depend on flavor type. Therefore, we strongly advocate for further research, increased user awareness regarding flavors in ECs, and rigorous regulatory scrutiny to protect public health.
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Affiliation(s)
- Felix Effah
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE London, UK; UK Health Security Agency, Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire OX11 ORQ, UK.
| | - John Adragna
- Division of Environmental Medicine, New York University Langone Health, New York, NY, USA
| | - David Luglio
- Division of Environmental Medicine, New York University Langone Health, New York, NY, USA
| | - Alexis Bailey
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE London, UK
| | - Tim Marczylo
- UK Health Security Agency, Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire OX11 ORQ, UK
| | - Terry Gordon
- Division of Environmental Medicine, New York University Langone Health, New York, NY, USA
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5
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Raduka A, Gao N, Chatburn RL, Rezaee F. Electronic cigarette exposure disrupts airway epithelial barrier function and exacerbates viral infection. Am J Physiol Lung Cell Mol Physiol 2023; 325:L580-L593. [PMID: 37698113 PMCID: PMC11068398 DOI: 10.1152/ajplung.00135.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/07/2023] [Accepted: 09/06/2023] [Indexed: 09/13/2023] Open
Abstract
The use of electronic cigarettes (e-cigs), especially among teenagers, has reached alarming and epidemic levels, posing a significant threat to public health. However, the short- and long-term effects of vaping on the airway epithelial barrier are unclear. Airway epithelial cells are the forefront protectors from viruses and pathogens. They contain apical junctional complexes (AJCs), which include tight junctions (TJs) and adherens junctions (AJs) formed between adjacent cells. Previously, we reported respiratory syncytial virus (RSV) infection, the leading cause of acute lower respiratory infection-related hospitalization in children and high-risk adults, induces a "leaky airway" by disrupting the epithelial AJC structure and function. We hypothesized chemical components of e-cigs disrupt airway epithelial barrier and exacerbate RSV-induced airway barrier dysfunction. Using confluent human bronchial epithelial (16HBE) cells and well-differentiated normal human bronchial epithelial (NHBE) cells, we found that exposure to extract and aerosol e-cig nicotine caused a significant decrease in transepithelial electrical resistance (TEER) and the structure of the AJC even at noncytotoxic concentrations. Western blot analysis of 16HBE cells exposed to e-cig nicotine extract did not reveal significant changes in AJC proteins. Exposure to aerosolized e-cig cinnamon or menthol flavors also induced barrier disruption and aggravated nicotine-induced airway barrier dysfunction. Moreover, preexposure to nicotine aerosol increased RSV infection and the severity of RSV-induced airway barrier disruption. Our findings demonstrate that e-cig exposure disrupts the airway epithelial barrier and exacerbates RSV-induced damage. Knowledge gained from this study will provide awareness of adverse e-cig respiratory effects and positively impact the mitigation of e-cig epidemic.NEW & NOTEWORTHY Electronic cigarette (e-cig) use, especially in teens, is alarming and at epidemic proportions, threatening public health. Our study shows that e-cig nicotine exposure disrupts airway epithelial tight junctions and increases RSV-induced barrier dysfunction. Furthermore, exposure to aerosolized flavors exaggerates e-cig nicotine-induced airway barrier dysfunction. Our study confirms that individual and combined components of e-cigs deleteriously impact the airway barrier and that e-cig exposure increases susceptibility to viral infection.
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Affiliation(s)
- Andjela Raduka
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States
| | - Nannan Gao
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States
| | - Robert L Chatburn
- Enterprise Respiratory Care Research Cleveland Clinic, Cleveland Clinic Children's, Cleveland, Ohio, United States
| | - Fariba Rezaee
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States
- Center for Pediatric Pulmonary Medicine, Cleveland Clinic Children's, Cleveland, Ohio, United States
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6
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Yanina IY, Genin VD, Genina EA, Mudrak DA, Navolokin NA, Bucharskaya AB, Kistenev YV, Tuchin VV. Multimodal Diagnostics of Changes in Rat Lungs after Vaping. Diagnostics (Basel) 2023; 13:3340. [PMID: 37958237 PMCID: PMC10650729 DOI: 10.3390/diagnostics13213340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/09/2023] [Accepted: 10/13/2023] [Indexed: 11/15/2023] Open
Abstract
(1) Background: The use of electronic cigarettes has become widespread in recent years. The use of e-cigarettes leads to milder pathological conditions compared to traditional cigarette smoking. Nevertheless, e-liquid vaping can cause morphological changes in lung tissue, which affects and impairs gas exchange. This work studied the changes in morphological and optical properties of lung tissue under the action of an e-liquid aerosol. To do this, we implemented the "passive smoking" model and created the specified concentration of aerosol of the glycerol/propylene glycol mixture in the chamber with the animal. (2) Methods: In ex vivo studies, the lungs of Wistar rats are placed in the e-liquid for 1 h. For in vivo studies, Wistar rats were exposed to the e-liquid vapor in an aerosol administration chamber. After that, lung tissue samples were examined ex vivo using optical coherence tomography (OCT) and spectrometry with an integrating sphere. Absorption and reduced scattering coefficients were estimated for the control and experimental groups. Histological sections were made according to the standard protocol, followed by hematoxylin and eosin staining. (3) Results: Exposure to e-liquid in ex vivo and aerosol in in vivo studies was found to result in the optical clearing of lung tissue. Histological examination of the lung samples showed areas of emphysematous expansion of the alveoli, thickening of the alveolar septa, and the phenomenon of plasma permeation, which is less pronounced in in vivo studies than for the exposure of e-liquid ex vivo. E-liquid aerosol application allows for an increased resolution and improved imaging of lung tissues using OCT. Spectral studies showed significant differences between the control group and the ex vivo group in the spectral range of water absorption. It can be associated with dehydration of lung tissue owing to the hyperosmotic properties of glycerol and propylene glycol, which are the main components of e-liquids. (4) Conclusions: A decrease in the volume of air in lung tissue and higher packing of its structure under e-liquid vaping causes a better contrast of OCT images compared to intact lung tissue.
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Affiliation(s)
- Irina Yu. Yanina
- Institution of Physics, Saratov State University, 410012 Saratov, Russia; (V.D.G.); (E.A.G.); (V.V.T.)
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050 Tomsk, Russia; (A.B.B.); (Y.V.K.)
| | - Vadim D. Genin
- Institution of Physics, Saratov State University, 410012 Saratov, Russia; (V.D.G.); (E.A.G.); (V.V.T.)
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050 Tomsk, Russia; (A.B.B.); (Y.V.K.)
- Science Medical Center, Saratov State University, 410012 Saratov, Russia
| | - Elina A. Genina
- Institution of Physics, Saratov State University, 410012 Saratov, Russia; (V.D.G.); (E.A.G.); (V.V.T.)
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050 Tomsk, Russia; (A.B.B.); (Y.V.K.)
- Science Medical Center, Saratov State University, 410012 Saratov, Russia
| | - Dmitry A. Mudrak
- Department of Pathological Anatomy, Saratov State Medical University, 410012 Saratov, Russia; (D.A.M.); (N.A.N.)
| | - Nikita A. Navolokin
- Department of Pathological Anatomy, Saratov State Medical University, 410012 Saratov, Russia; (D.A.M.); (N.A.N.)
- Experimental Department, Center for Collective Use of Experimental Oncology, Saratov State Medical University, 410012 Saratov, Russia
- State Healthcare Institution, Saratov City Clinical Hospital No. 1 Named after Yu.Ya. Gordeev, 410017 Saratov, Russia
| | - Alla B. Bucharskaya
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050 Tomsk, Russia; (A.B.B.); (Y.V.K.)
- Science Medical Center, Saratov State University, 410012 Saratov, Russia
- Department of Pathological Anatomy, Saratov State Medical University, 410012 Saratov, Russia; (D.A.M.); (N.A.N.)
| | - Yury V. Kistenev
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050 Tomsk, Russia; (A.B.B.); (Y.V.K.)
| | - Valery V. Tuchin
- Institution of Physics, Saratov State University, 410012 Saratov, Russia; (V.D.G.); (E.A.G.); (V.V.T.)
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, 634050 Tomsk, Russia; (A.B.B.); (Y.V.K.)
- Science Medical Center, Saratov State University, 410012 Saratov, Russia
- Institute of Precision Mechanics and Control, FRC “Saratov Scientific Centre of the Russian Academy of Sciences”, 410028 Saratov, Russia
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Effah F, Elzein A, Taiwo B, Baines D, Bailey A, Marczylo T. In Vitro high-throughput toxicological assessment of E-cigarette flavors on human bronchial epithelial cells and the potential involvement of TRPA1 in cinnamon flavor-induced toxicity. Toxicology 2023; 496:153617. [PMID: 37595738 DOI: 10.1016/j.tox.2023.153617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/06/2023] [Accepted: 08/15/2023] [Indexed: 08/20/2023]
Abstract
Electronic cigarettes (ECs) are considered a less hazardous alternative to tobacco smoking but are not harmless. Growing concerns about the safety profiles of flavors in e-liquids underpin the need for this study. Here, we screened 53 nicotine-free flavored e-liquids (across 15 flavor categories) across a 3-point concentration range (0.25%, 0.5%, and 1% v/v) in a high-throughput fashion in human bronchial epithelial (HBEC-3KT) submerged cell cultures to identify 'toxic hits' using in vitro endpoint assays comprising cell count, cell viability, and lactate dehydrogenase (LDH). We observed significant, dose-dependent adverse effects only with cinnamon, vanilla tobacco, and hazelnut e-liquids compared to media-only and PG/VG vehicle controls. Hence, we further analyzed these three flavors for their effects on HBEC-3KT proliferation, mitochondrial health, and oxidative stress. A significant decrease in cell proliferation after 36 h was observed for each e-liquid toxic hit compared to media-only and PG/VG controls. Hazelnut (at all concentrations) and vanilla tobacco (1%) increased cytoplasmic reactive oxygen species generation compared to media-only and PG/VG controls. Conversely, all three flavors at 0.5% and 1% significantly decreased mitochondrial membrane potential compared to PG/VG and media-only controls. Chemical analysis revealed that all three flavors contained volatile organic compounds. We hypothesized that the cytotoxicity of cinnamon might be mediated via TRPA1; however, TRPA1 antagonist AP-18 (10 μM) did not mitigate these effects, and cinnamon significantly increased TRPA1 transcript levels. Therefore, pathways mediating cinnamon's cytotoxicity warrant further investigations. This study could inform public health authorities on the relative health risks assessment following exposure to EC flavor ingredients.
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Affiliation(s)
- Felix Effah
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE London, UK; UK Health Security Agency, Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire OX11 ORQ, UK.
| | - Atallah Elzein
- UK Health Security Agency, Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire OX11 ORQ, UK
| | - Benjamin Taiwo
- Physiology Section, St George's University of London, Cranmer Terrace, SW17 0RE London, UK
| | - Deborah Baines
- Infection and Immunity Institute, St George's University of London, Cranmer Terrace, SW17 0RE London, UK
| | - Alexis Bailey
- Pharmacology Section, St George's University of London, Cranmer Terrace, SW17 0RE London, UK
| | - Tim Marczylo
- UK Health Security Agency, Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire OX11 ORQ, UK.
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8
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Roxlau ET, Pak O, Hadzic S, Garcia-Castro CF, Gredic M, Wu CY, Schäffer J, Selvakumar B, Pichl A, Spiegelberg D, Deutscher J, Bednorz M, Schäfer K, Kraut S, Kosanovic D, Zeidan EM, Kojonazarov B, Herold S, Strielkov I, Guenther A, Wilhelm J, Khalifa MMA, Taye A, Brandes RP, Hecker M, Grimminger F, Ghofrani HA, Schermuly RT, Seeger W, Sommer N, Weissmann N. Nicotine promotes e-cigarette vapour-induced lung inflammation and structural alterations. Eur Respir J 2023; 61:2200951. [PMID: 37105573 PMCID: PMC10285110 DOI: 10.1183/13993003.00951-2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 03/19/2023] [Indexed: 04/29/2023]
Abstract
BACKGROUND Electronic cigarette (e-cigarette) vapour is gaining popularity as an alternative to tobacco smoking and can induce acute lung injury. However, the specific role of nicotine in e-cigarette vapour and its long-term effects on the airways, lung parenchyma and vasculature remain unclear. RESULTS In vitro exposure to nicotine-containing e-cigarette vapour extract (ECVE) or to nicotine-free e-cigarette vapour extract (NF ECVE) induced changes in gene expression of epithelial cells and pulmonary arterial smooth muscle cells (PASMCs), but ECVE in particular caused functional alterations (e.g. a decrease in human and mouse PASMC proliferation by 29.3±5.3% and 44.3±8.4%, respectively). Additionally, acute inhalation of nicotine-containing e-cigarette vapour (ECV) but not nicotine-free e-cigarette vapour (NF ECV) increased pulmonary endothelial permeability in isolated lungs. Long-term in vivo exposure of mice to ECV for 8 months significantly increased the number of inflammatory cells, in particular lymphocytes, compared to control and NF ECV in the bronchoalveolar fluid (BALF) (ECV: 853.4±150.8 cells·mL-1; control: 37.0±21.1 cells·mL-1; NF ECV: 198.6±94.9 cells·mL-1) and in lung tissue (ECV: 25.7±3.3 cells·mm-3; control: 4.8±1.1 cells·mm-3; NF ECV: 14.1±2.2 cells·mm-3). BALF cytokines were predominantly increased by ECV. Moreover, ECV caused significant changes in lung structure and function (e.g. increase in airspace by 17.5±1.4% compared to control), similar to mild tobacco smoke-induced alterations, which also could be detected in the NF ECV group, albeit to a lesser degree. In contrast, the pulmonary vasculature was not significantly affected by ECV or NF ECV. CONCLUSIONS NF ECV components induce cell type-specific effects and mild pulmonary alterations, while inclusion of nicotine induces significant endothelial damage, inflammation and parenchymal alterations.
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Affiliation(s)
- Elsa T Roxlau
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Joint first authors
| | - Oleg Pak
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Joint first authors
| | - Stefan Hadzic
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Claudia F Garcia-Castro
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Marija Gredic
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Cheng-Yu Wu
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Julia Schäffer
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Balachandar Selvakumar
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Sharjah Institute of Medical Research (SIMR), College of Medicine - University of Sharjah (UoS), Sharjah, United Arab Emirates
| | - Alexandra Pichl
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - David Spiegelberg
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Janik Deutscher
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Mariola Bednorz
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Katharina Schäfer
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Simone Kraut
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Djuro Kosanovic
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Esraa M Zeidan
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, El-Minia, Egypt
| | - Baktybek Kojonazarov
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Institute for Lung Health (ILH), Giessen, Germany
| | - Susanne Herold
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Ievgen Strielkov
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Andreas Guenther
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Jochen Wilhelm
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Institute for Lung Health (ILH), Giessen, Germany
| | - Mohamed M A Khalifa
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Minia University, El-Minia, Egypt
| | - Ashraf Taye
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, South Valley University, Qena, Egypt
| | - Ralf P Brandes
- Institute for Cardiovascular Physiology, Goethe University, Cardio-Pulmonary Institute (CPI), Frankfurt, Germany
| | - Matthias Hecker
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Friedrich Grimminger
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Hossein A Ghofrani
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Department of Medicine, Imperial College London, London, UK
| | - Ralph T Schermuly
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Werner Seeger
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
- Institute for Lung Health (ILH), Giessen, Germany
- Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Natascha Sommer
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Norbert Weissmann
- Justus Liebig University, Excellence Cluster Cardio-Pulmonary Institute (CPI), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany
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9
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Tellez CS, Grimes MJ, Juri DE, Do K, Willink R, Dye WW, Wu G, Picchi MA, Belinsky SA. Flavored E-cigarette product aerosols induce transformation of human bronchial epithelial cells. Lung Cancer 2023; 179:107180. [PMID: 36989612 PMCID: PMC10159902 DOI: 10.1016/j.lungcan.2023.107180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/15/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023]
Abstract
OBJECTIVES E-cigarettes are the most commonly used nicotine containing products among youth. In vitro studies support the potential for e-cigarettes to cause cellular stress in vivo; however, there have been no studies to address whether exposure to e-liquid aerosols can induce cell transformation, a process strongly associated with pre-malignancy. We examined whether weekly exposure of human bronchial epithelial cell (HBEC) lines to e-cigarette aerosols would induce transformation and concomitant changes in gene expression and promoter hypermethylation. MATERIALS AND METHODS An aerosol delivery system exposed three HBEC lines to unflavored e-liquid with 1.2% nicotine, 3 flavored products with nicotine, or the Kentucky reference cigarette once a week for 12 weeks. Colony formation in soft agar, RNA-sequencing, and the EPIC Beadchip were used to evaluate transformation, genome-wide expression and methylation changes. RESULTS Jamestown e-liquid aerosol induced transformation of HBEC2 and HBEC26, while unflavored and Blue Pucker transformed HBEC26. Cigarette smoke aerosol transformed HBEC4 and HBEC26 at efficiencies up to 3-fold greater than e-liquids. Transformed clones exhibited extensive reprogramming of the transcriptome with common and distinct gene expression changes observed between the cigarette and e-liquids. Transformation by e-liquids induced alterations in canonical pathways implicated in lung cancer that included axonal guidance and NRF2. Gene methylation, while prominent in cigarette-induced transformed clones, also affected hundreds of genes in HBEC2 transformed by Jamestown. Many genes with altered expression or epigenetic-mediated silencing were also affected in lung tumors from smokers. CONCLUSIONS These studies show that exposure to e-liquid aerosols can induce a pre-malignant phenotype in lung epithelial cells. While the Food and Drug Administration banned the sale of flavored cartridge-based electric cigarettes, consumers switched to using flavored products through other devices. Our findings clearly support expanding studies to evaluate transformation potency for the major categories of e-liquid flavors to better inform risk from these complex mixtures.
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Affiliation(s)
- Carmen S. Tellez
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Marcie J. Grimes
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Daniel E. Juri
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Kieu Do
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Randy Willink
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Wendy W. Dye
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Guodong Wu
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Maria A. Picchi
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
| | - Steven A. Belinsky
- Lung Cancer Program Lovelace Biomedical Research Institute Albuquerque, NM
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10
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Bishop E, East N, Miazzi F, Fiebelkorn S, Breheny D, Gaca M, Thorne D. A contextualised e-cigarette testing strategy shows flavourings do not impact lung toxicity in vitro. Toxicol Lett 2023; 380:1-11. [PMID: 36935081 DOI: 10.1016/j.toxlet.2023.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 02/27/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023]
Abstract
Vaping has the potential to reduce the individual health risks associated with smoking and e-cigarette flavours have been reported to help smokers' transition from cigarettes. In this manuscript, we provide evidence to support the reduced risk potential of e-cigarette aerosols and flavours by assessing commercially available e-liquids (Vuse ePod - Manufactured by British American Tobacco) in a 2D in vitro screening approach. We also analysed selected flavours using a more physiologically relevant 3D (MucilAir) whole aerosol exposure model, measuring toxicity and functional endpoints such as Trans Epithelial Electrical Resistance, Cilia Beat Frequency and Active Area. To contextualise responses, we have compared e-cigarette aerosol to cigarette smoke (1R6F research cigarette) and calculated the percentage reduction using a point of departure approach. We show that aerosolised flavoured e-liquids, (appropriately stewarded) do not increase the overall measured aerosol toxicity when compared to cigarette smoke. In fact, we demonstrate that the measured in vitro cellular toxicity of flavoured e-cigarette products remains >95% reduced when compared to cigarette smoke toxicity, using point of departure (IC80) approach. These data indicate that the overall product toxicity is not increased in a flavour dependent manner and that flavoured e-cigarette products can potentially play a role in tobacco harm reduction.
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Affiliation(s)
- E Bishop
- B.A.T. (Investments) Limited, Regents Park Road, Millbrook, Southampton SO15 8TL, UK
| | - N East
- B.A.T. (Investments) Limited, Regents Park Road, Millbrook, Southampton SO15 8TL, UK
| | - F Miazzi
- B.A.T. (Investments) Limited, Regents Park Road, Millbrook, Southampton SO15 8TL, UK
| | - S Fiebelkorn
- B.A.T. (Investments) Limited, Regents Park Road, Millbrook, Southampton SO15 8TL, UK
| | - D Breheny
- B.A.T. (Investments) Limited, Regents Park Road, Millbrook, Southampton SO15 8TL, UK
| | - M Gaca
- B.A.T. (Investments) Limited, Regents Park Road, Millbrook, Southampton SO15 8TL, UK
| | - D Thorne
- B.A.T. (Investments) Limited, Regents Park Road, Millbrook, Southampton SO15 8TL, UK
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11
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Herbert J, Kelty JS, Laskin JD, Laskin DL, Gow AJ. Menthol flavoring in e-cigarette condensate causes pulmonary dysfunction and cytotoxicity in precision cut lung slices. Am J Physiol Lung Cell Mol Physiol 2023; 324:L345-L357. [PMID: 36692165 PMCID: PMC10026991 DOI: 10.1152/ajplung.00222.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 01/05/2023] [Accepted: 01/14/2023] [Indexed: 01/25/2023] Open
Abstract
E-cigarette consumption is under scrutiny by regulatory authorities due to concerns about product toxicity, lack of manufacturing standards, and increasing reports of e-cigarette- or vaping-associated acute lung injury. In vitro studies have demonstrated cytotoxicity, mitochondrial dysfunction, and oxidative stress induced by unflavored e-cigarette aerosols and flavoring additives. However, e-cigarette effects on the complex lung parenchyma remain unclear. Herein, the impact of e-cigarette condensates with or without menthol flavoring on functional, structural, and cellular responses was investigated using mouse precision cut lung slices (PCLS). PCLS were exposed to e-cigarette condensates prepared from aerosolized vehicle, nicotine, nicotine + menthol, and menthol e-fluids at doses from 50 to 500 mM. Doses were normalized to the glycerin content of vehicle. Video-microscopy of PCLS revealed impaired contractile responsiveness of airways to methacholine and dampened ciliary beating following exposure to menthol-containing condensates at concentrations greater than 300 mM. Following 500 mM menthol-containing condensate exposure, epithelial exfoliation in intrabronchial airways was identified in histological sections of PCLS. Measurement of lactate dehydrogenase release, mitochondrial water-soluble-tetrazolium salt-1 conversion, and glutathione content supported earlier findings of nicotine or nicotine + menthol e-cigarette-induced dose-dependent cytotoxicity and oxidative stress responses. Evaluation of PCLS metabolic activity revealed dose-related impairment of mitochondrial oxidative phosphorylation and glycolysis after exposure to menthol-containing condensates. Taken together, these data demonstrate prominent menthol-induced pulmonary toxicity and impairment of essential physiological functions in the lung, which warrants concerns about e-cigarette consumer safety and emphasizes the need for further investigations of molecular mechanisms of toxicity and menthol effects in an experimental model of disease.
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Affiliation(s)
- Julia Herbert
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, United States
| | - Jacklyn S Kelty
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, United States
| | - Jeffrey D Laskin
- Department of Environmental and Occupational Health and Justice, School of Public Health, Rutgers University, Piscataway, New Jersey, United States
| | - Debra L Laskin
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, United States
| | - Andrew J Gow
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, United States
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12
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Soo J, Easwaran M, Erickson‐DiRenzo E. Impact of Electronic Cigarettes on the Upper Aerodigestive Tract: A Comprehensive Review for Otolaryngology Providers. OTO Open 2023; 7:e25. [PMID: 36998560 PMCID: PMC10046796 DOI: 10.1002/oto2.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/18/2022] [Accepted: 12/02/2022] [Indexed: 02/19/2023] Open
Abstract
Objective The use and effects of electronic (e)-cigarettes (e-cigs) are particularly relevant for otolaryngology providers as tobacco plays a major role in benign and malignant diseases of the upper aerodigestive tract. This review aims to (1) summarize the recent policies regarding e-cigs and important patterns of use and (2) serve as a comprehensive resource for clinical providers on the known biologic and clinical effects of e-cigs on the upper aerodigestive tract. Data Sources PubMed/MEDLINE. Review Methods We conducted a narrative review on (1) general information on e-cig use and informative findings in the lower respiratory system and a comprehensive review on (2) the effects of e-cigs on cell and animal models and the clinical implications of these products on human health as is relevant to otolaryngology. Conclusions Although e-cigs are likely less harmful than conventional cigarettes, preliminary research on e-cigs suggest several deleterious effects including in the upper aerodigestive tract. Due to this, there has been increased interest in restricting e-cig usage, particularly among the adolescent population, and caution in recommending e-cigs to current smokers. Implications for Practice Chronic e-cig use is likely to have clinical implications. It is critical for otolaryngology providers to be aware of the rapidly changing regulations and use patterns regarding e-cigs and how e-cigs influence human health, particularly with regards to the upper aerodigestive tract, to accurately council patients regarding potential risks and benefits of use.
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Affiliation(s)
- Joanne Soo
- Department of Otolaryngology–Head & Neck Surgery Stanford University School of Medicine Stanford California USA
| | - Meena Easwaran
- Department of Otolaryngology–Head & Neck Surgery Stanford University School of Medicine Stanford California USA
| | - Elizabeth Erickson‐DiRenzo
- Department of Otolaryngology–Head & Neck Surgery Stanford University School of Medicine Stanford California USA
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13
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Alhadyan SK, Sivaraman V, Onyenwoke RU. E-cigarette Flavors, Sensory Perception, and Evoked Responses. Chem Res Toxicol 2022; 35:2194-2209. [PMID: 36480683 DOI: 10.1021/acs.chemrestox.2c00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The chemosensory experiences evoked by flavors encompass a number of unique sensations that include olfactory stimuli (smell), gustatory stimuli (taste, i.e., salty, sweet, sour, bitter, and umami (also known as "savoriness")), and chemesthesis (touch). As such, the responses evoked by flavors are complex and, as briefly stated above, involve multiple perceptive mechanisms. The practice of adding flavorings to tobacco products dates back to the 17th century but is likely much older. More recently, the electronic cigarette or "e-cigarette" and its accompanying flavored e-liquids emerged on to the global market. These new products contain no combustible tobacco but often contain large concentrations (reported from 0 to more than 50 mg/mL) of nicotine as well as numerous flavorings and/or flavor chemicals. At present, there are more than 400 e-cigarette brands available along with potentially >15,000 different/unique flavored products. However, surprisingly little is known about the flavors/flavor chemicals added to these products, which can account for >1% by weight of some e-liquids, and their resultant chemosensory experiences, and the US FDA has done relatively little, until recently, to regulate these products. This article will discuss e-cigarette flavors and flavor chemicals, their elicited responses, and their sensory effects in some detail.
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Affiliation(s)
- Shatha K Alhadyan
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Vijay Sivaraman
- Department of Biological and Biomedical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Rob U Onyenwoke
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States.,Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, North Carolina 27707, United States
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14
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Noël A, Ghosh A. Carbonyl Profiles of Electronic Nicotine Delivery System (ENDS) Aerosols Reflect Both the Chemical Composition and the Numbers of E-Liquid Ingredients-Focus on the In Vitro Toxicity of Strawberry and Vanilla Flavors. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:16774. [PMID: 36554655 PMCID: PMC9779252 DOI: 10.3390/ijerph192416774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Propylene glycol (PG) and glycerin (G) are the most widely used humectants in electronic nicotine delivery system (ENDS) devices. Carbonyls are present in aerosols produced when ENDS devices heat PG and G. Whether aerosolized PG and G are innocuous to the lungs has not been established. Here, we determined the chemical profiles of ENDS aerosols containing three humectant ratios (30/70, 50/50 and 70/30, PG/VG), for three flavors (strawberry, vanilla and Catalan cream) containing either 12 or 18 mg/mL of nicotine. Additionally, we examined the in vitro toxicity of the strawberry- and vanilla-flavored ENDS aerosol in human lung epithelial cells (BEAS-2B) exposed at the air-liquid interface for 1 h. For strawberry- and vanilla-flavored aerosols produced by a 3rd-generation ENDS device with the same PG/G ratio, the e-liquid nicotine content of 12 and 18 mg/mL did not transfer to the aerosol with substantial differences in concentrations. Our data also indicate the presence of carbonyls in all three flavored e-cig aerosols analyzed, with levels exceeding 1 µg/puff for acetone, butyraldehyde, and acetaldehyde, in strawberry-, vanilla, and Catalan cream-flavored e-cig aerosols, respectively. Furthermore, closed-system ENDS of the fourth generation emitted trace levels of carbonyls in the aerosols (<0.3 µg/puff), while open-system tank-style ENDS of the third generation produced elevated levels of harmful chemicals, including acrolein (>1 µg/puff), formaldehyde (>5 µg/puff), and m- & p-tolualdehyde (>4 µg/puff). Moreover, under non-cytotoxic conditions, BEAS-2B cells exposed to strawberry-flavored aerosols exhibited significantly increased reactive oxygen and nitric oxide species (ROS/NOS) levels in cell media compared to air controls, while vanilla-flavored ENDS aerosols up-regulated the expression of pro-inflammatory and oxidative stress markers. Our data suggest (a) that ENDS aerosol chemical composition will vary based upon the presence and concentration of the initial e-liquid ingredients, with a pronounced impact of the flavoring components; and (b) short-term exposures to flavored ENDS aerosols may impair lung cells' redox signaling in a flavor-specific manner.
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15
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Effah F, Taiwo B, Baines D, Bailey A, Marczylo T. Pulmonary effects of e-liquid flavors: a systematic review. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2022; 25:343-371. [PMID: 36154615 PMCID: PMC9590402 DOI: 10.1080/10937404.2022.2124563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Electronic cigarettes (ECs) are purported to be tobacco harm-reduction products whose degree of harm has been highly debated. EC use is considered less hazardous than smoking but is not expected to be harmless. Following the banning of e-liquid flavors in countries such as the US, Finland, Ukraine, and Hungary, there are growing concerns regarding the safety profile of e-liquid flavors used in ECs. While these are employed extensively in the food industry and are generally regarded as safe (GRAS) when ingested, GRAS status after inhalation is unclear. The aim of this review was to assess evidence from 38 reports on the adverse effects of flavored e-liquids on the respiratory system in both in vitro and in vivo studies published between 2006 and 2021. Data collected demonstrated greater detrimental effects in vitro with cinnamon (9 articles), strawberry (5 articles), and menthol (10 articles), flavors than other flavors. The most reported effects among these investigations were perturbations of pro-inflammatory biomarkers and enhanced cytotoxicity. There is sufficient evidence to support the toxicological impacts of diacetyl- and cinnamaldehyde-containing e-liquids following human inhalation; however, safety profiles on other flavors are elusive. The latter may result from inconsistencies between experimental approaches and uncertainties due to the contributions from other e-liquid constituents. Further, the relevance of the concentration ranges to human exposure levels is uncertain. Evidence indicates that an adequately controlled and consistent, systematic toxicological investigation of a broad spectrum of e-liquid flavors may be required at biologically relevant concentrations to better inform public health authorities on the risk assessment following exposure to EC flavor ingredients.
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Affiliation(s)
- Felix Effah
- Pharmacology Section, St George’s University of London, London, UK
- Radiation, Chemical and Environmental Hazards, UK Health Security Agency, Didcot, UK
| | - Benjamin Taiwo
- Physiology Section, St George’s University of London, London, UK
| | - Deborah Baines
- Infection and Immunity Institute, St George’s University of London, London, UK
| | - Alexis Bailey
- Pharmacology Section, St George’s University of London, London, UK
| | - Tim Marczylo
- Radiation, Chemical and Environmental Hazards, UK Health Security Agency, Didcot, UK
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16
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Novelli CE, Higginbotham EJ, Kapanke KA, Webber-Ritchey KJ, Parker CH, Simonovich SD. A systematic review examining the pulmonary effects of electronic vapor delivery systems. J Clin Anesth 2022; 82:110952. [PMID: 36007478 DOI: 10.1016/j.jclinane.2022.110952] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 07/28/2022] [Accepted: 08/09/2022] [Indexed: 10/31/2022]
Abstract
STUDY OBJECTIVE Despite the popularity of vaping and electronic vapor delivery systems (EVDS), the healthcare community remains largely unfamiliar with their potential to induce harm. The purpose of this systematic review is to identify how EVDS use affects the pulmonary system in order to support future anesthetic guidelines for patients who vape. DESIGN Systematic Review. An electronic search of databases CINAHL and PubMed was performed in October 2020. STUDY ELIGIBILITY CRITERIA Studies were included if they were deemed original research published in English, if they were performed exclusively in humans or on human tissue, if they examined the effects of EVDS on pulmonary function or tissue, and/or if they produced quantitative data. Studies were excluded if they utilized animal samples, studied subjects under the age of 18, presented expert opinions or reviews, offered qualitative data, reported case studies, or only evaluated EVDS' efficacy as a smoking cessation tool. MAIN RESULTS This review identified six EVDS-induced pulmonary implications warranting anesthetic consideration: alterations in pulmonary function tests, disrupted ventilation, impaired mucociliary clearance, tissue destruction, a disrupted immune response, and oxidative stress with DNA fragmentation. CONCLUSION A total of 38 studies described the effects of EVDS on pulmonary function, airway epithelial tissue, and inflammatory mechanisms that may lead to chronic pulmonary disease. Anesthesia providers are encouraged to assess patients for EVDS use during the preoperative period and use the information generated by this systematic review to drive subsequent care.
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Affiliation(s)
- Corinne E Novelli
- University of Chicago Medical Center, Chicago, IL, United States of America
| | | | - Karen A Kapanke
- Northshore University HealthSystem School of Nurse Anesthesia, Evanston, IL, United States of America.
| | - Kashica J Webber-Ritchey
- School of Nursing, College of Science and Health, DePaul University, 990 W Fullerton, Chicago, IL, United States of America.
| | - Christopher H Parker
- DePaul University Libraries, 2350 N Kenmore Ave, Chicago, IL 60614, United States of America.
| | - Shannon D Simonovich
- School of Nursing, College of Science and Health, DePaul University, 990 W Fullerton, Chicago, IL, United States of America.
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17
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Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways. Respir Res 2022; 23:216. [PMID: 35999544 PMCID: PMC9400210 DOI: 10.1186/s12931-022-02142-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 08/15/2022] [Indexed: 11/10/2022] Open
Abstract
Background Electronic cigarettes (e-cigarettes) are used worldwide as a substitute for conventional cigarettes. Although they are primarily intended to support smoking cessation, e-cigarettes have been identified as a gateway to smoking habits for young people. Multiple recent reports have described the health effects of inhaling e-cigarettes. E-cigarette liquid (e-liquid) is mainly composed of propylene glycol (PG) and glycerol (Gly), and the aerosol generated by these devices primarily contains these two components. Thus, this study aimed to evaluate the effects of PG and Gly on human small airway epithelial cells (SAECs). Methods SAECs were exposed to PG or Gly, and cell proliferation, cell viability, lactate dehydrogenase (LDH) release, DNA damage, cell cycle, and apoptosis were evaluated. Additionally, SAECs derived from chronic obstructive pulmonary disease (COPD) patients (COPD-SAECs) were investigated. Results Exposure of SAECs to PG significantly inhibited proliferation (1%, PG, p = 0.021; 2–4% PG, p < 0.0001) and decreased cell viability (1–4% PG, p < 0.0001) in a concentration-dependent manner. Gly elicited similar effects but to a reduced degree as compared to the same concentration of PG. PG also increased LDH release in a concentration-dependent manner (3% PG, p = 0.0055; 4% PG, p < 0.0001), whereas Gly did not show a significant effect on LDH release. SAECs exposed to 4% PG contained more cells that were positive for phosphorylated histone H2AX (p < 0.0001), a marker of DNA damage, and an increased proportion of cells in the G1 phase (p < 0.0001) and increased p21 expression (p = 0.0005). Moreover, caspase 3/7-activated cells and cleaved poly (ADP-ribose) polymerase 1 expression were increased in SAECs exposed to 4% PG (p = 0.0054). Furthermore, comparing COPD-SAECs to SAECs without COPD in PG exposure, cell proliferation, cell viability, DNA damage and apoptosis were significantly greater in COPD-SAECs. Conclusion PG damaged SAECs more than Gly. In addition, COPD-SAECs were more susceptible to PG than SAECs without COPD. Usage of e-cigarettes may be harmful to the respiratory system, especially in patients with COPD.
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18
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Vivarelli F, Granata S, Rullo L, Mussoni M, Candeletti S, Romualdi P, Fimognari C, Cruz-Chamorro I, Carrillo-Vico A, Paolini M, Canistro D. On the toxicity of e-cigarettes consumption: Focus on pathological cellular mechanisms. Pharmacol Res 2022; 182:106315. [PMID: 35724819 DOI: 10.1016/j.phrs.2022.106315] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 06/09/2022] [Accepted: 06/14/2022] [Indexed: 10/18/2022]
Abstract
Tobacco smoking remains without a doubt one of the leading causes of premature death worldwide. In combination with conventional protocols for smoking cessation, e-cigarettes have been proposed as a useful tool to quit smoking. Advertised as almost free of toxic effects, e-cigarettes have rapidly increased their popularity, becoming a sought-after device, especially among young people. Recently some health concerns about e-cigarette consumption are being raised. It is well known that they can release several toxic compounds, some of which are carcinogenic to humans, and emerging results are now outlining the risks related to the onset of respiratory and cardiovascular diseases and even cancer. The present review shows the emerging evidence about the role of technical components of the devices, the e-liquid composition as well as customization by consumers. The primary topics we discuss are the main toxicological aspects associated with e-cigarette consumption, focusing on the molecular pathways involved. Here it will be shown how exposure to e-cigarette aerosol induces stress/mitochondrial toxicity, DNA breaks/fragmentation following the same pathological pathways triggered by tobacco smoke, including the deregulation of molecular signalling axis associated with cancer progression and cell migration. Risk to fertility and pregnancy, as well as cardiovascular risk associated with e-cigarette use, have also been reported.
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Affiliation(s)
- Fabio Vivarelli
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy.
| | - Silvia Granata
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy; Department of Medicine and Surgery - University of Milano - Bicocca
| | - Laura Rullo
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Matilde Mussoni
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Sanzio Candeletti
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Patrizia Romualdi
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
| | - Carmela Fimognari
- Department for Life Quality Studies, Alma Mater Studiorum-University of Bologna, Corso d'Augusto 237, 47921 Rimini, Italy
| | - Ivan Cruz-Chamorro
- Instituto de Biomedicina de Sevilla, IBiS (Universidad de Sevilla, HUVR, Junta de Andalucía, CSIC), 41013 Seville, Spain; Departamento de Bioquímica Médica y Biología Molecular e Inmunología, Universidad de Sevilla, 41009 Seville, Spain
| | - Antonio Carrillo-Vico
- Instituto de Biomedicina de Sevilla, IBiS (Universidad de Sevilla, HUVR, Junta de Andalucía, CSIC), 41013 Seville, Spain; Departamento de Bioquímica Médica y Biología Molecular e Inmunología, Universidad de Sevilla, 41009 Seville, Spain
| | - Moreno Paolini
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy.
| | - Donatella Canistro
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum-University of Bologna, Via Irnerio 48, 40126 Bologna, Italy
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19
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Marrocco A, Singh D, Christiani DC, Demokritou P. E-Cigarette (E-Cig) Liquid Composition and Operational Voltage Define the In Vitro Toxicity of Δ8Tetrahydrocannabinol/Vitamin E Acetate (Δ8THC/VEA) E-Cig Aerosols. Toxicol Sci 2022; 187:279-297. [PMID: 35478015 PMCID: PMC9154258 DOI: 10.1093/toxsci/kfac047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The 2019 United States outbreak of E-cigarette (e-cig), or Vaping, Associated Acute Lung Injury (EVALI) has been linked to presence of vitamin E acetate (VEA) in Δ8tetrahydrocannabinol (Δ8THC)-containing e-liquids, as supported by VEA detection in patient biological samples. However, the pathogenesis of EVALI and the complex physicochemical properties of e-cig emissions remain unclear, raising concerns on health risks of vaping. This study investigates the effect of Δ8THC/VEA e-liquids and e-cig operational voltage on in vitro toxicity of e-cig aerosols. A novel E-cigExposure Generation System platform was used to generate and characterize e-cig aerosols from a panel of Δ8THC/VEA or nicotine-based e-liquids at 3.7 or 5 V. Human lung Calu-3 cells and THP-1 monocytes were exposed to cell culture media conditioned with collected e-cig aerosol condensate at doses of 85 and 257 puffs/m2 lung surface for 24 h, whereafter specific toxicological endpoints were assessed (including cytotoxicity, metabolic activity, reactive oxygen species generation, apoptosis, and inflammatory cytokines). Higher concentrations of gaseous volatile organic compounds were emitted from Δ8THC/VEA compared with nicotine-based e-liquids, especially at 5 V. Emitted PM2.5 concentrations in aerosol were higher for Δ8THC/VEA at 5 V and averagely for nicotine-based e-liquids at 3.7 V. Overall, aerosols from nicotine-based e-liquids showed higher bioactivity than Δ8THC/VEA aerosols in THP-1 cells, with no apparent differences in Calu-3 cells. Importantly, presence of VEA in Δ8THC and menthol flavoring in nicotine-based e-liquids increased cytotoxicity of aerosols across both cell lines, especially at 5 V. This study systematically investigates the physicochemical and toxicological properties of a model of Δ8THC/VEA and nicotine e-cigarette condensate exposure demonstrating that pyrolysis of these mixtures can generate hazardous toxicants whose synergistic actions potentially drive acute lung injury upon inhalation.
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Affiliation(s)
- Antonella Marrocco
- To whom correspondence should be addressed at Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Harvard University, 665 Huntington Avenue, Building 1, Room 1310, Boston, MA 02115, USA. E-mail:
| | - Dilpreet Singh
- Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts 02115, USA
| | - David C Christiani
- Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts 02115, USA
| | - Philip Demokritou
- Department of Environmental Health, Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts 02115, USA,Department of Environmental and Population Health Bio-Sciences, Environmental Occupational Health Sciences Institute, School of Public Health, Rutgers University, Piscataway, New Jersey 08854, USA
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20
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The Effects of e-Cigarette Aerosol on Oral Cavity Cells and Tissues: A Narrative Review. TOXICS 2022; 10:toxics10020074. [PMID: 35202260 PMCID: PMC8878056 DOI: 10.3390/toxics10020074] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 01/28/2022] [Accepted: 02/04/2022] [Indexed: 02/04/2023]
Abstract
A wealth of research has comprehensively documented the harmful effects of traditional cigarette smoking and nicotine on human health. The lower rate of exposure to harmful chemicals and toxic substances offered by alternative electronic smoking devices (e-cigarettes, vaping, etc.) has made these methods of smoking popular, especially among adolescents and young adults, and they are regarded frequently as safer than regular cigarettes. During vaporization of these so-called e-liquids, toxins, carcinogens and various other chemical substances may be released and inhaled by the user. Data on the potential human health effect attendant on exposure to e-vapor are based mainly on animal and in vitro studies. The oral tissues are the first locus of direct interaction with the components of the inhaled vapor. However, the short-term as well as long-term effects of the exposure are not known. The aim of the review is to briefly present data on the effects of the chemical components and toxins of e-cigarette vapor on oral cavity cells and tissues of oral health.
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21
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Khachatoorian C, McWhirter KJ, Luo W, Pankow JF, Talbot P. Tracing the movement of electronic cigarette flavor chemicals and nicotine from refill fluids to aerosol, lungs, exhale, and the environment. CHEMOSPHERE 2022; 286:131494. [PMID: 34392198 PMCID: PMC8787941 DOI: 10.1016/j.chemosphere.2021.131494] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/09/2021] [Accepted: 07/07/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Given the high concentrations of nicotine and flavor chemicals in EC (electronic cigarette) fluids, it is important to determine how efficiently they transfer to aerosols, how well they are retained by users (exposure), and if they are exhaled into the environment where they settle of surfaces forming ECEAR (EC exhaled aerosol residue). OBJECTIVES To quantify the flavor chemicals and nicotine in refill fluids, inhaled aerosols, and exhaled aerosols. Then deduce their retention and contribution to ECEAR. METHODS Flavor chemicals and nicotine were identified and quantified by GC-MS in two refill fluids, smoking machine-generated aerosols, and aerosols exhaled by 10 human participants (average age 21; 7 males). Machine generated aerosols were made with varying puff durations and two wattages (40 and 80). Participants generated exhale ad libitum; their exhale was quantified, and chemical retention and contribution to ECEAR was modeled. RESULTS "Dewberry Cream" had five dominant (≥1 mg/mL) flavor chemicals (maltol, ethyl maltol, vanillin, ethyl vanillin, furaneol), while "Cinnamon Roll" had one (cinnamaldehyde). Nicotine transferred well to aerosols irrespective of topography; however, transfer efficiencies of flavor chemicals depended on the chemical, puff volume, puff duration, pump head, and EC power. Participants could be classified as "mouth inhalers" or "lung inhalers" based on their exhale of flavor chemicals and nicotine and retention. Lung inhalers had high retention and exhaled low concentrations of EC chemicals. Only mouth inhalers exhaled sufficient concentrations of flavor chemicals/nicotine to contribute to chemical deposition on environmental surfaces (ECEAR). CONCLUSION These data help distinguish two types of EC users, add to our knowledge of chemical exposure during vaping, and provide information useful in regulating EC use.
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Affiliation(s)
- Careen Khachatoorian
- Cell, Molecular, and Developmental Biology Graduate Program, University of California, Riverside, Riverside, CA, USA.
| | - Kevin J McWhirter
- Department of Civil and Environmental Engineering, Portland State University, Portland, OR, USA.
| | - Wentai Luo
- Department of Civil and Environmental Engineering, Portland State University, Portland, OR, USA.
| | - James F Pankow
- Department of Civil and Environmental Engineering, Portland State University, Portland, OR, USA.
| | - Prue Talbot
- Department of Molecular, Cell & Systems Biology University of California, Riverside, Riverside, CA, USA.
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22
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Forest V, Mercier C, Pourchez J. Considerations on dosimetry for in vitro assessment of e-cigarette toxicity. Respir Res 2022; 23:358. [PMID: 36528600 PMCID: PMC9758947 DOI: 10.1186/s12931-022-02286-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
Electronic cigarettes (or e-cigarettes) can be used as smoking cessation aid. Some studies tend to show that they are less hazardous than tobacco cigarettes, even if it does not mean they are completely safe. The huge variation in study designs assessing in vitro toxicity of e-cigarettes aerosol makes it difficult to make comparisons and draw robust and irrefutable conclusions. In this paper, we review this heterogeneity (in terms of e-cigarette products, biological models, and exposure conditions) with a special focus on the wide disparity in the doses used as well as in the way they are expressed. Finally, we discuss the major issue of dosimetry and show how dosimetry tools enable to align data between different exposure systems or data from different laboratories and therefore allow comparisons to help further exploring the risk potential of e-cigarettes.
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Affiliation(s)
- Valérie Forest
- grid.7429.80000000121866389Mines Saint-Etienne, Univ Jean Monnet, INSERM, U1059 Sainbiose, Centre CIS, 158 Cours Fauriel, CS 62362, 42023 Saint-Etienne Cedex 2, France
| | - Clément Mercier
- grid.7429.80000000121866389Mines Saint-Etienne, Univ Jean Monnet, INSERM, U1059 Sainbiose, Centre CIS, 158 Cours Fauriel, CS 62362, 42023 Saint-Etienne Cedex 2, France
| | - Jérémie Pourchez
- grid.7429.80000000121866389Mines Saint-Etienne, Univ Jean Monnet, INSERM, U1059 Sainbiose, Centre CIS, 158 Cours Fauriel, CS 62362, 42023 Saint-Etienne Cedex 2, France
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23
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Goenka S, Simon SR. Effects of E-Cigarette Refill Liquid Flavorings with and without Nicotine on Human Retinal Pigment Epithelial Cells: A Preliminary Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182111655. [PMID: 34770169 PMCID: PMC8582700 DOI: 10.3390/ijerph182111655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/30/2021] [Accepted: 11/03/2021] [Indexed: 02/07/2023]
Abstract
Smoking is an etiologic factor for age-related macular degeneration (AMD). Although cigarette smoke has been extensively researched for retinal pigment epithelial (RPE) cell degeneration, the potential for adverse effects on the retinal epithelium following exposure to flavored e-cigarette refill liquid has never been explored. In this preliminary study, we have examined the effects of 20 e-liquids (10 different flavored nicotine-free and 10 nicotine-rich e-liquids) used in e-cigarettes on the metabolic activity, membrane integrity, and mitochondrial membrane potential of RPE cells. Our results showed that of the flavors studied over the concentration range: 0.5, 1, and 2% v/v for a duration of 48 h, cinnamon was the most toxic and menthol was the second most toxic, while other flavors showed lesser or no cytotoxicity. The presence of nicotine augmented cytotoxicity for cinnamon, menthol, strawberry, vanilla, and banana while for other flavors there was no synergism. Together, our results demonstrate that exposure of RPE to flavored e-cigarette refill liquids caused significant cytotoxicity and may be a risk factor for the development of retinal pathogenesis, although further in-depth studies are necessary.
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Affiliation(s)
- Shilpi Goenka
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, USA;
- Department of Biochemistry and Cellular Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA
- Correspondence:
| | - Sanford R. Simon
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794-5281, USA;
- Department of Biochemistry and Cellular Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA
- Department of Pathology, Stony Brook University, Stony Brook, NY 11794, USA
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24
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Re DB, Hilpert M, Saglimbeni B, Strait M, Ilievski V, Coady M, Talayero M, Wilmsen K, Chesnais H, Balac O, Glabonjat RA, Slavkovich V, Yan B, Graziano J, Navas-Acien A, Kleiman NJ. Exposure to e-cigarette aerosol over two months induces accumulation of neurotoxic metals and alteration of essential metals in mouse brain. ENVIRONMENTAL RESEARCH 2021; 202:111557. [PMID: 34245728 PMCID: PMC8578258 DOI: 10.1016/j.envres.2021.111557] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/12/2021] [Accepted: 06/17/2021] [Indexed: 05/15/2023]
Abstract
Despite a recent increase in e-cigarette use, the adverse human health effects of exposure to e-cigarette aerosol, especially on the central nervous system (CNS), remain unclear. Multiple neurotoxic metals have been identified in e-cigarette aerosol. However, it is unknown whether those metals accumulate in the CNS at biologically meaningful levels. To answer this question, two groups of mice were whole-body exposed twice a day, 5 days a week, for two months, to either a dose of e-cigarette aerosol equivalent to human secondhand exposure, or a 5-fold higher dose. After the last exposure, the olfactory bulb, anterior and posterior frontal cortex, striatum, ventral midbrain, cerebellum, brainstem, remaining brain tissue and spinal cord were collected for metal quantification by inductively coupled plasma mass spectrometry and compared to tissues from unexposed control mice. The two-month exposure caused significant accumulation of several neurotoxic metals in various brain areas - for some metals even at the low exposure dose. The most striking increases were measured in the striatum. For several metals, including Cr, Cu, Fe, Mn, and Pb, similar accumulations are known to be neurotoxic in mice. Decreases in some essential metals were observed across the CNS. Our findings suggest that chronic exposure to e-cigarette aerosol could lead to CNS neurotoxic metal deposition and endogenous metal dyshomeostasis, including potential neurotoxicity. We conclude that e-cigarette-mediated metal neurotoxicity may pose long-term neurotoxic and neurodegenerative risks for e-cigarette users and bystanders.
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Affiliation(s)
- Diane B Re
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA; Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA.
| | - Markus Hilpert
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA.
| | - Brianna Saglimbeni
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA; Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA
| | - Madeleine Strait
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA; Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA
| | - Vesna Ilievski
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA
| | - Maxine Coady
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; Master in Public Health Program, Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Maria Talayero
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA
| | - Kai Wilmsen
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; Master in Public Health Program, Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Helene Chesnais
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA
| | - Olgica Balac
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA
| | - Ronald A Glabonjat
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA
| | - Vesna Slavkovich
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA
| | - Beizhan Yan
- NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA; Lamont-Doherty Earth Observatory, Geochemistry Department, 203 Comer, 61 Route 9W - PO Box 1000, Palisades, NY, 10964-8000, USA
| | - Joseph Graziano
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA
| | - Ana Navas-Acien
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA
| | - Norman J Kleiman
- Department of Environmental Health Sciences, Columbia University, New York, NY, 10032, USA; NIEHS Center for Environmental Health in Northern Manhattan, Columbia University, New York, NY, 10032, USA.
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25
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Park HR, Vallarino J, O'Sullivan M, Wirth C, Panganiban RA, Webb G, Shumyatcher M, Himes BE, Park JA, Christiani DC, Allen J, Lu Q. Electronic cigarette smoke reduces ribosomal protein gene expression to impair protein synthesis in primary human airway epithelial cells. Sci Rep 2021; 11:17517. [PMID: 34471210 PMCID: PMC8410828 DOI: 10.1038/s41598-021-97013-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 08/05/2021] [Indexed: 12/27/2022] Open
Abstract
The widespread use of electronic cigarettes (e-cig) is a serious public health concern; however, mechanisms by which e-cig impair the function of airway epithelial cells-the direct target of e-cig smoke-are not fully understood. Here we report transcriptomic changes, including decreased expression of many ribosomal genes, in airway epithelial cells in response to e-cig exposure. Using RNA-seq we identify over 200 differentially expressed genes in air-liquid interface cultured primary normal human bronchial epithelial (NHBE) exposed to e-cig smoke solution from commercial e-cig cartridges. In particular, exposure to e-cig smoke solution inhibits biological pathways involving ribosomes and protein biogenesis in NHBE cells. Consistent with this effect, expression of corresponding ribosomal proteins and subsequent protein biogenesis are reduced in the cells exposed to e-cig. Gas chromatography/mass spectrometry (GC/MS) analysis identified the presence of five flavoring chemicals designated as 'high priority' in regard to respiratory health, and methylglyoxal in e-cig smoke solution. Together, our findings reveal the potential detrimental effect of e-cig smoke on ribosomes and the associated protein biogenesis in airway epithelium. Our study calls for further investigation into how these changes in the airway epithelium contribute to the current epidemic of lung injuries in e-cig users.
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Affiliation(s)
- Hae-Ryung Park
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - Jose Vallarino
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - Michael O'Sullivan
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - Charlotte Wirth
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - Ronald A Panganiban
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - Gabrielle Webb
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - Maya Shumyatcher
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Blanca E Himes
- Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jin-Ah Park
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - David C Christiani
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA
| | - Joseph Allen
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA.
- Harvard T.H. Chan School of Public Health, Room 404-L401 Park Drive, Boston, MA, 02215, USA.
| | - Quan Lu
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, 02215, USA.
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26
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Bonner E, Chang Y, Christie E, Colvin V, Cunningham B, Elson D, Ghetu C, Huizenga J, Hutton SJ, Kolluri SK, Maggio S, Moran I, Parker B, Rericha Y, Rivera BN, Samon S, Schwichtenberg T, Shankar P, Simonich MT, Wilson LB, Tanguay RL. The chemistry and toxicology of vaping. Pharmacol Ther 2021; 225:107837. [PMID: 33753133 PMCID: PMC8263470 DOI: 10.1016/j.pharmthera.2021.107837] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 02/19/2021] [Accepted: 03/01/2021] [Indexed: 12/20/2022]
Abstract
Vaping is the process of inhaling and exhaling an aerosol produced by an e-cigarette, vape pen, or personal aerosolizer. When the device contains nicotine, the Food and Drug Administration (FDA) lists the product as an electronic nicotine delivery system or ENDS device. Similar electronic devices can be used to vape cannabis extracts. Over the past decade, the vaping market has increased exponentially, raising health concerns over the number of people exposed and a nationwide outbreak of cases of severe, sometimes fatal, lung dysfunction that arose suddenly in otherwise healthy individuals. In this review, we discuss the various vaping technologies, which are remarkably diverse, and summarize the use prevalence in the U.S. over time by youths and adults. We examine the complex chemistry of vape carrier solvents, flavoring chemicals, and transformation products. We review the health effects from epidemiological and laboratory studies and, finally, discuss the proposed mechanisms underlying some of these health effects. We conclude that since much of the research in this area is recent and vaping technologies are dynamic, our understanding of the health effects is insufficient. With the rapid growth of ENDS use, consumers and regulatory bodies need a better understanding of constituent-dependent toxicity to guide product use and regulatory decisions.
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Affiliation(s)
- Emily Bonner
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Yvonne Chang
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Emerson Christie
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Victoria Colvin
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Brittany Cunningham
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Daniel Elson
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Christine Ghetu
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Juliana Huizenga
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Sara J Hutton
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Siva K Kolluri
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Stephanie Maggio
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Ian Moran
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Bethany Parker
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Yvonne Rericha
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Brianna N Rivera
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Samantha Samon
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Trever Schwichtenberg
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Prarthana Shankar
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Michael T Simonich
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Lindsay B Wilson
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA
| | - Robyn L Tanguay
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, Corvallis, OR, USA.
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27
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Tellez CS, Juri DE, Phillips LM, Do K, Yingling CM, Thomas CL, Dye WW, Wu G, Kishida S, Kiyono T, Belinsky SA. Cytotoxicity and Genotoxicity of E-Cigarette Generated Aerosols Containing Diverse Flavoring Products and Nicotine in Oral Epithelial Cell Lines. Toxicol Sci 2021; 179:220-228. [PMID: 33226417 DOI: 10.1093/toxsci/kfaa174] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Electronic cigarettes are the most commonly used nicotine containing product among teenagers. The oral epithelium is the first site of exposure and our recent work revealed considerable diversity among e-liquids for composition and level of chemical constituents that impact nicotine deposition in a human oral-trachea cast and affect the formation of reactive carbonyls. Here, we evaluate the dose response for cytotoxicity and genotoxicity of e-cigarette-generated aerosols from 10 diverse flavored e-liquid products with and without nicotine compared with unflavored in 3 immortalized oral epithelial cell lines. Three e-liquids, Blue Pucker, Love Potion, and Jamestown caused ≥20% cell toxicity assessed by the neutral red uptake assay. Nine products induced significant levels of oxidative stress up to 2.4-fold quantified by the ROS-Glo assay in at least 1 cell line, with dose response seen for Love Potion with and without nicotine across all cell lines. Lipid peroxidation detected by the thiobarbituric acid reactive substances assay was less common among products; however, dose response increases up to 12-fold were seen for individual cell lines. Micronuclei formation indicative of genotoxicity was increased up to 5-fold for some products. Blue Pucker was the most genotoxic e-liquid, inducing micronuclei across all cell lines irrespective of nicotine status. A potency score derived from all assays identified Blue Pucker and Love Potion as the most hazardous e-liquids. These in vitro acute exposure studies provide new insight about the potential for some flavored vaping products to induce significant levels of oxidative stress and genotoxicity.
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Affiliation(s)
- Carmen S Tellez
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Daniel E Juri
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Loryn M Phillips
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Kieu Do
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Christin M Yingling
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Cindy L Thomas
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Wendy W Dye
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Guodong Wu
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
| | - Shosei Kishida
- Departments of Biochemistry and Genetics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Tohru Kiyono
- Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Chiba, Japan
| | - Steven A Belinsky
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108
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28
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Jarrell ZR, Smith MR, He X, Orr M, Jones DP, Go YM. Firsthand and Secondhand Exposure Levels of Maltol-Flavored Electronic Nicotine Delivery System Vapors Disrupt Amino Acid Metabolism. Toxicol Sci 2021; 182:70-81. [PMID: 34009373 DOI: 10.1093/toxsci/kfab051] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Electronic nicotine delivery system (ENDS) use has become a popular, generally regarded as safe, alternative to tobacco use. The e-liquids used for ENDS vapor generation commonly contain flavoring agents, such as maltol, which have been subjected to little investigation of their effects on lung health from ENDS usage. In the present study, we examined the impacts of firsthand (3.9 mM) and secondhand (3.9 µM) exposure levels to maltol-flavored ENDS vapors on lung metabolism. Human lung bronchial epithelial cells were exposed to ENDS vapors using a robotic system for controlled generation and delivery of exposures, and the effects on metabolism were evaluated using high-resolution metabolomics. The results show that maltol in e-liquids impacts lung airway epithelial cell metabolism at both firsthand and secondhand exposure levels. The effects of maltol were most notably seen in amino acid metabolism while oxidative stress was observed with exposure to all ENDS vapors including e-liquids alone and maltol-contained e-liquids. Many effects of firsthand exposure were also observed with secondhand exposure, suggesting need for systematic investigation of both firsthand and secondhand effects of flavored ENDS vapors on lung metabolism and risk of lung disease.
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Affiliation(s)
- Zachery R Jarrell
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University, Atlanta, Georgia 30322
| | - Matthew Ryan Smith
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University, Atlanta, Georgia 30322
| | - Xiaojia He
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University, Atlanta, Georgia 30322
| | - Michael Orr
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University, Atlanta, Georgia 30322
| | - Dean P Jones
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University, Atlanta, Georgia 30322
| | - Young-Mi Go
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Emory University, Atlanta, Georgia 30322
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29
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The impact of vaping on ocular health: a literature review. Int Ophthalmol 2021; 41:2925-2932. [PMID: 33860887 DOI: 10.1007/s10792-021-01842-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 04/03/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Vaping, or the use of electronic cigarettes, was initially introduced as a step toward smoking cessation, but has become an increasingly popular option for smokers. Though advertised as safer than conventional cigarettes, these devices have been found to contain carcinogenic chemicals, air pollutants, and heavy metals. The purpose of this article is to shed light on the known effects of vaping on the ocular setting and raise the discussion about additional potential effects that may call for further investigation. METHODS A comprehensive literature search was conducted for publications pertaining to the effects of vaping on the eye. Relevant studies and findings were summarized in this article. RESULTS It was found that aldehydes and free radicals present in electronic cigarettes may induce a disturbance in tear film stability, and vape flavorings may damage the lipid layer through peroxidation. Corneal staining has been shown to appear following exposure to e-cigarette vapor, with nicotine and acrolein potentially inducing an inflammatory response in corneal epithelial cells. In addition, nicotine has been shown to induce nystagmus, exert vasoconstrictive effects on ocular blood flow, and may interfere with retinal light-adapted vision. Vape-related explosions, though unpredictable, may also result in decreased visual acuity along with long-term ocular trauma. CONCLUSION Research discussing both the short-term and long-term effects of vaping on the eye is limited. However, the potential harms of substances such as nicotine and aldehydes warrant additional investigation and increased education about the detriment that electronic cigarettes may inflict on sensitive organs.
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30
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Escobar YNH, Morrison CB, Chen Y, Hickman E, Love CA, Rebuli ME, Surratt JD, Ehre C, Jaspers I. Differential responses to e-cig generated aerosols from humectants and different forms of nicotine in epithelial cells from nonsmokers and smokers. Am J Physiol Lung Cell Mol Physiol 2021; 320:L1064-L1073. [PMID: 33825493 DOI: 10.1152/ajplung.00525.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In the United States, millions of adults use electronic cigarettes (e-cigs), and a majority of these users are former or current cigarette smokers. It is unclear, whether prior smoking status affects biological responses induced by e-cigs. In this study, differentiated human nasal epithelial cells (hNECs) from nonsmokers and smokers at air-liquid interface were acutely exposed to the e-cig generated aerosols of humectants, propylene glycol (PG), and glycerol (GLY). Mucin levels were examined in the apical washes, and cytokine levels were assessed in the basolateral supernatants 24 h postexposure. The aerosol from the GLY exposure increased mucin 5, subtype AC (MUC5AC) levels in the apical wash of hNECs from nonsmokers, but not smokers. However, the aerosol from GLY induced pro-inflammatory responses in hNECs from smokers. We also exposed hNECs from nonsmokers and smokers to e-cig generated aerosol from PG:GLY with freebase nicotine or nicotine salt. The PG:GLY with freebase nicotine exposure increased MUC5AC and mucin 5, subtype B (MUC5B) levels in hNECs from nonsmokers, but the nicotine salt exposure did not. The PG:GLY with nicotine salt exposure increased pro-inflammatory cytokines in hNECs from smokers, which was not seen with the freebase nicotine exposure. Taken together, these data indicate that the e-cig generated aerosols from the humectants, mostly GLY, and the type of nicotine used cause differential effects in airway epithelial cells from nonsmokers and smokers. As e-cig use is increasing, it is important to understand that the biological effects of e-cig use are likely dependent on prior cigarette smoke exposure.
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Affiliation(s)
- Yael-Natalie H Escobar
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina at Chapel Hill, North Carolina
| | - Cameron B Morrison
- Marsico Lung Institute, University of North Carolina at Chapel Hill, North Carolina
| | - Yuzhi Chen
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, North Carolina
| | - Elise Hickman
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina at Chapel Hill, North Carolina
| | - Charlotte A Love
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina at Chapel Hill, North Carolina
| | - Meghan E Rebuli
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina at Chapel Hill, North Carolina.,Department of Pediatrics, University of North Carolina at Chapel Hill, North Carolina
| | - Jason D Surratt
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill, North Carolina.,Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, North Carolina.,Department of Pediatrics, University of North Carolina at Chapel Hill, North Carolina
| | - Ilona Jaspers
- Curriculum in Toxicology and Environmental Medicine, University of North Carolina at Chapel Hill, North Carolina.,Department of Pediatrics, University of North Carolina at Chapel Hill, North Carolina
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31
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Yan B, Zagorevski D, Ilievski V, Kleiman NJ, Re DB, Navas-Acien A, Hilpert M. Identification of newly formed toxic chemicals in E-cigarette aerosols with Orbitrap mass spectrometry and implications on E-cigarette control. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2021; 27:141-148. [PMID: 34448631 PMCID: PMC9035225 DOI: 10.1177/14690667211040207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The increasing use of electronic nicotine delivery systems (ENDS) is of concern due to multiple emerging adverse health effects. Most analyses of the harmful chemicals of ENDS have targeted metals or carbonyls generated by thermal decomposition of carrier liquids such as propylene glycol. However, new complex compounds not routinely identified and with unknown health consequences could be formed. ENDS aerosol samples were collected by the direct aerosol droplet deposition method. Untargeted analysis was performed using Orbitrap mass spectrometry with high mass accuracy. We identified more than 30 "features" in the aerosol characterized by pairs of the mass-to-charge ratio "m/z" of the compound and the retention time. We identified several compounds containing nicotine and propylene glycol (NIC-PG), whose abundance relative to nicotine increased along with vaping power used. On the basis of the prediction by the Environmental Protection Agency Toxicity Estimation Software Tool, these compounds exert developmental toxicity. In addition, a nitrogen-containing compound, likely tributylamine (a known lung irritant), was identified based on the molecular weight. This compound has not been previously identified in ENDS e-liquids and aerosols. ENDS produce not only small toxic compounds such as aldehydes, but also large complex toxic compounds such as NIC-PG. Predicted development toxicity for NIC-PG is concerning for fetal development in pregnant women who use ENDS, children exposed to secondhand or thirdhand ENDS aerosols, and teenage ENDS users whose brains are still developing. The strong positive association between NIC-PG levels and ENDS power output supports regulating high-powered ENDS.
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Affiliation(s)
- Beizhan Yan
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA
| | - Dimitri Zagorevski
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy NY, 12180, USA
| | - Vesna Ilievski
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Norman J. Kleiman
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Diane B. Re
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Ana Navas-Acien
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Markus Hilpert
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
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32
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Toxicology of flavoring- and cannabis-containing e-liquids used in electronic delivery systems. Pharmacol Ther 2021; 224:107838. [PMID: 33746051 DOI: 10.1016/j.pharmthera.2021.107838] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 03/11/2021] [Indexed: 12/15/2022]
Abstract
Electronic cigarettes (e-cigarettes) were introduced in the United States in 2007 and by 2014 they were the most popular tobacco product amongst youth and had overtaken use of regular tobacco cigarettes. E-cigarettes are used to aerosolize a liquid (e-liquid) that the user inhales. Flavorings in e-liquids is a primary reason for youth to initiate use of e-cigarettes. Evidence is growing in the scientific literature that inhalation of some flavorings is not without risk of harm. In this review, 67 original articles (primarily cellular in vitro) on the toxicity of flavored e-liquids were identified in the PubMed and Scopus databases and evaluated critically. At least 65 individual flavoring ingredients in e-liquids or aerosols from e-cigarettes induced toxicity in the respiratory tract, cardiovascular and circulatory systems, skeletal system, and skin. Cinnamaldehyde was most frequently reported to be cytotoxic, followed by vanillin, menthol, ethyl maltol, ethyl vanillin, benzaldehyde and linalool. Additionally, modern e-cigarettes can be modified to aerosolize cannabis as dried plant material or a concentrated extract. The U.S. experienced an outbreak of lung injuries, termed e-cigarette, or vaping, product use-associated lung injury (EVALI) that began in 2019; among 2,022 hospitalized patients who had data on substance use (as of January 14, 2020), 82% reported using a delta-9-tetrahydrocannabinol (main psychoactive component in cannabis) containing e-cigarette, or vaping, product. Our literature search identified 33 articles related to EVALI. Vitamin E acetate, a diluent and thickening agent in cannabis-based products, was strongly linked to the EVALI outbreak in epidemiologic and laboratory studies; however, e-liquid chemistry is highly complex, and more than one mechanism of lung injury, ingredient, or thermal breakdown product may be responsible for toxicity. More research is needed, particularly with regard to e-cigarettes (generation, power settings, etc.), e-liquids (composition, bulk or vaped form), modeled systems (cell type, culture type, and dosimetry metrics), biological monitoring, secondhand exposures and contact with residues that contain nicotine and flavorings, and causative agents and mechanisms of EVALI toxicity.
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33
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Rebuli ME, Glista-Baker E, Hoffman JR, Duffney PF, Robinette C, Speen AM, Pawlak EA, Dhingra R, Noah TL, Jaspers I. Electronic-Cigarette Use Alters Nasal Mucosal Immune Response to Live-attenuated Influenza Virus. A Clinical Trial. Am J Respir Cell Mol Biol 2021; 64:126-137. [PMID: 33095645 PMCID: PMC7781000 DOI: 10.1165/rcmb.2020-0164oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Inhalation of tobacco smoke has been linked to increased risk of viral infection, such as influenza. Inhalation of electronic-cigarette (e-cigarette) aerosol has also recently been linked to immune suppression within the respiratory tract, specifically the nasal mucosa. We propose that changes in the nasal mucosal immune response modify antiviral host-defense responses in e-cigarette users. Nonsmokers, cigarette smokers, and e-cigarette users were inoculated with live-attenuated influenza virus (LAIV) to safely examine the innate immune response to influenza infection. Before and after LAIV inoculation, we collected nasal epithelial-lining fluid, nasal lavage fluid, nasal-scrape biopsy specimens, urine, and blood. Endpoints examined include cytokines and chemokines, influenza-specific IgA, immune-gene expression, and markers of viral load. Statistical analysis included primary comparisons of cigarette and e-cigarette groups with nonsmokers, as well as secondary analysis of demographic factors as potential modifiers. Markers of viral load did not differ among the three groups. Nasal-lavage-fluid anti-LAIV IgA levels increased in nonsmokers after LAIV inoculation but did not increase in e-cigarette users and cigarette smokers. LAIV-induced gene-expression changes in nasal biopsy specimens differed in cigarette smokers and e-cigarette users as compared with nonsmokers, with a greater number of genes changed in e-cigarette users, mostly resulting in decreased expression. The top downregulated genes in cigarette smokers were SMPD3, NOS2A, and KLRB1, and the top downregulated genes in e-cigarette users were MR1, NT5E, and HRAS. Similarly, LAIV-induced cytokine levels in nasal epithelial-lining fluid differed among the three groups, including decreased antiviral host-defense mediators (IFNγ, IL6, and IL12p40). We also detected that sex interacted with tobacco-product exposure to modify LAIV-induced immune-gene expression. Our results demonstrate that e-cigarette use altered nasal LAIV-induced immune responses, including gene expression, cytokine and chemokine release, and LAIV-specific IgA levels. Together, these data suggest that e-cigarette use induces changes in the nasal mucosa that are consistent with the potential for altered respiratory antiviral host-defense function. Clinical trial registered with www.clinicaltrials.gov (NCT 02019745).
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Affiliation(s)
- Meghan E Rebuli
- Curriculum in Toxicology and Environmental Medicine.,Center for Environmental Medicine, Asthma and Lung Biology, and.,Department of Pediatrics, School of Medicine
| | | | - Jessica R Hoffman
- Curriculum for the Environment and Ecology, College of Arts and Sciences
| | | | | | - Adam M Speen
- Curriculum in Toxicology and Environmental Medicine
| | - Erica A Pawlak
- Center for Environmental Medicine, Asthma and Lung Biology, and
| | - Radhika Dhingra
- Institute for Environmental Health Solutions, and.,Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Terry L Noah
- Center for Environmental Medicine, Asthma and Lung Biology, and.,Department of Pediatrics, School of Medicine
| | - Ilona Jaspers
- Curriculum in Toxicology and Environmental Medicine.,Center for Environmental Medicine, Asthma and Lung Biology, and.,Department of Pediatrics, School of Medicine.,Institute for Environmental Health Solutions, and
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34
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Zhang R, Jones MM, Dornsife RE, Wu T, Sivaraman V, Tarran R, Onyenwoke RU. JUUL e-liquid exposure elicits cytoplasmic Ca 2+ responses and leads to cytotoxicity in cultured airway epithelial cells. Toxicol Lett 2021; 337:46-56. [PMID: 33253780 PMCID: PMC7772262 DOI: 10.1016/j.toxlet.2020.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 10/27/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022]
Abstract
RATIONALE The popularity of new and emerging tobacco products such as E-cigarettes (E-cigs) is rapidly expanding worldwide. However, uncertainties surrounding the potential health consequences due to the use of such products exist and warrant further study. METHODS Cultured A549 and Calu-3 airway epithelia were exposed to three out of the eight types of JUUL brand e-liquids ("Mint", "Virginia Tobacco" and "Menthol", all containing 3% nicotine at 1% and 3% (vol/vol) dilutions) and assessed for viability using a resazurin-based assay. Intracellular Ca2+ levels were measured using fluorescent indicators and pro-inflammatory cytokine levels were monitored by quantitative PCR (qPCR). Cultures were also analyzed by flow cytometry to evaluate apoptotic markers and cell viability. RESULTS Exposing the airway epithelial cells to the flavored JUUL e-liquids led to significant cytotoxicity, with the "Mint" flavor being the overall most cytotoxic. The "Mint" flavored e-liquid also led to significant elevations in intracellular Ca2+ and upregulation of the pro-inflammatory cytokine IL-6 and early apoptotic marker Annexin V. CONCLUSIONS JUUL e-liquid challenge resulted in a loss of airway epithelial cell viability, induced pro-inflammatory responses and eventually caused apoptosis.
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Affiliation(s)
- Rui Zhang
- Department of Respiratory and Critical Care Medicine, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, PR China; Biomanufacturing Research Institute and Technology Enterprise (BRITE), Durham, NC, United States
| | - Myles M Jones
- Department of Biological and Biomedical Sciences, Durham, NC, United States
| | - Ronna E Dornsife
- Biomanufacturing Research Institute and Technology Enterprise (BRITE), Durham, NC, United States
| | - Tongde Wu
- Biomanufacturing Research Institute and Technology Enterprise (BRITE), Durham, NC, United States; Department of Pharmaceutical Sciences, North Carolina Central University, Durham, NC, United States
| | - Vijay Sivaraman
- Department of Biological and Biomedical Sciences, Durham, NC, United States
| | - Robert Tarran
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Rob U Onyenwoke
- Biomanufacturing Research Institute and Technology Enterprise (BRITE), Durham, NC, United States; Department of Pharmaceutical Sciences, North Carolina Central University, Durham, NC, United States.
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35
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Wills TA, Soneji SS, Choi K, Jaspers I, Tam EK. E-cigarette use and respiratory disorders: an integrative review of converging evidence from epidemiological and laboratory studies. Eur Respir J 2021; 57:13993003.01815-2019. [PMID: 33154031 PMCID: PMC7817920 DOI: 10.1183/13993003.01815-2019] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 10/10/2020] [Indexed: 12/11/2022]
Abstract
Background Use of electronic cigarettes (e-cigarettes) is prevalent among adolescents and young adults, but there has been limited knowledge about health consequences in human populations. We conduct a systematic review and meta-analysis of results on respiratory disorders from studies of general-population samples and consider the mapping of these results to findings about biological processes linked to e-cigarettes in controlled laboratory studies. Method We conducted a literature search and meta-analysis of epidemiological studies on the association of e-cigarette use with asthma and with COPD. We discuss findings from laboratory studies about effects of e-cigarettes on four biological processes: cytotoxicity, oxidative stress/inflammation, susceptibility to infection and genetic expression. Results Epidemiological studies, both cross-sectional and longitudinal, show a significant association of e-cigarette use with asthma and COPD, controlling for cigarette smoking and other covariates. For asthma (n=15 studies), the pooled adjusted odds ratio (aOR) was 1.39 (95% CI 1.28–1.51); for COPD (n=9 studies) the aOR was 1.49 (95% CI 1.36–1.65). Laboratory studies consistently show an effect of e-cigarettes on biological processes related to respiratory harm and susceptibility to illness, with e-cigarette conditions differing significantly from clean-air controls, although sometimes less than for cigarettes. Conclusions The evidence from epidemiological studies meets established criteria for consistency, strength of effect, temporality, and in some cases a dose–response gradient. Biological plausibility is indicated by evidence from multiple laboratory studies. We conclude that e-cigarette use has consequences for asthma and COPD, which is of concern for respirology and public health. Epidemiological studies show a relationship of e-cigarette use with asthma and COPD, and laboratory studies show their adverse effects on four biological processes. It can be concluded that e-cigarette use is of significant concern for public health.https://bit.ly/3drH4pj
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Affiliation(s)
- Thomas A Wills
- Cancer Prevention Program, University of Hawaii Cancer Center, Honolulu, HI, USA
| | - Samir S Soneji
- Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Kelvin Choi
- Division of Intramural Research, National Institute on Minority Health and Health Disparities, Bethesda, MD, USA
| | - Ilona Jaspers
- Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Elizabeth K Tam
- Dept of Medicine, John A. Burns School of Medicine, Honolulu, HI, USA
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36
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Bracken-Clarke D, Kapoor D, Baird AM, Buchanan PJ, Gately K, Cuffe S, Finn SP. Vaping and lung cancer - A review of current data and recommendations. Lung Cancer 2021; 153:11-20. [PMID: 33429159 DOI: 10.1016/j.lungcan.2020.12.030] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/15/2020] [Accepted: 12/19/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Lung cancer is the most common cause of cancer mortality worldwide and, while tobacco smoke remains the primary cause, there is increasing concern that vaping and E-cigarette use may also increase lung cancer risk. This review concentrates on the current data, scholarship and active foci of research regarding potential cancer risk and oncogenic mechanisms of vaping and lung cancer. MATERIALS AND METHODS We performed a literature review of current and historical publications on lung cancer oncogenesis, vaping device/e-liquid contents and daughter products, molecular oncogenic mechanisms and the fundamental, potentially oncogenic, effects of electronic cigarette smoke/e-liquid products. RESULTS E-cigarette devices and vaping fluids demonstrably contain a series of both definite and probable oncogens including nicotine derivatives (e.g. nitrosnornicotine, nitrosamine ketone), polycyclic aromatic hydrocarbons, heavy metals (including organometal compounds) and aldehydes/other complex organic compounds. These arise both as constituents of the e-liquid (with many aldehydes and other complex organics used as flavourings) and as a result of pyrolysis/complex organic reactions in the electronic cigarette device (including unequivocal carcinogens such as formaldehyde - formed from pyrolysis of glycerol). Various studies demonstrate in vitro transforming and cytotoxic activity of these derivatives. E-cigarette device use has been significantly increasing - particularly amongst the younger cohort and non-smokers; thus, this is an area of significant concern for the future. CONCLUSION Although research remains somewhat equivocal, there is clear reason for concern regarding the potential oncogenicity of E-Cigarettes/E-Liquids with a strong basic and molecular science basis. Given lag times (extrapolating from tobacco smoke data) of perhaps 20 years, this may have significant future public health implications. Thus, the authors feel further study in this field is strongly warranted and consideration should be made for tighter control and regulation of these products.
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Affiliation(s)
| | - Dhruv Kapoor
- Department of Medical Oncology, St James' Hospital, Dublin, Ireland
| | - Anne Marie Baird
- School of Medicine, Trinity Translational Medicine Institute, Trinity College Dublin, Ireland
| | - Paul James Buchanan
- DCU Cancer Research, Faculty of Science and Health, Dublin City University, Dublin, Ireland; National Institute of Cellular Biotechnology, Dublin City University, Dublin, Ireland
| | - Kathy Gately
- Department of Clinical Medicine, Trinity College School of Medicine and St James's Hospital, Dublin, Ireland
| | - Sinead Cuffe
- Department of Medical Oncology, St James' Hospital, Dublin, Ireland
| | - Stephen P Finn
- Department of Pathology, St James' Hospital and Trinity College School of Medicine, Dublin, Ireland
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37
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Abouassali O, Chang M, Chidipi B, Martinez JL, Reiser M, Kanithi M, Soni R, McDonald TV, Herweg B, Saiz J, Calcul L, Noujaim SF. In vitro and in vivo cardiac toxicity of flavored electronic nicotine delivery systems. Am J Physiol Heart Circ Physiol 2021; 320:H133-H143. [PMID: 33216635 PMCID: PMC7847071 DOI: 10.1152/ajpheart.00283.2020] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 10/17/2020] [Accepted: 11/09/2020] [Indexed: 01/06/2023]
Abstract
The usage of flavored electronic nicotine delivery systems (ENDS) is popular, specifically in the teen and young adult age-groups. The possible cardiac toxicity of the flavoring aspect of ENDS is largely unknown. Vaping, a form of electronic nicotine delivery, uses "e-liquid" to generate "e-vapor," an aerosolized mixture of nicotine and/or flavors. We report our investigation into the cardiotoxic effects of flavored e-liquids. E-vapors containing flavoring aldehydes such as vanillin and cinnamaldehyde, as indicated by mass spectrometry, were more toxic in HL-1 cardiomyocytes than fruit-flavored e-vapor. Exposure of human induced pluripotent stem cell-derived cardiomyocytes to cinnamaldehyde or vanillin-flavored e-vapor affected the beating frequency and prolonged the field potential duration of these cells more than fruit-flavored e-vapor. In addition, vanillin aldehyde-flavored e-vapor reduced the human ether-à-go-go-related gene (hERG)-encoded potassium current in transfected human embryonic kidney cells. In mice, inhalation exposure to vanillin aldehyde-flavored e-vapor for 10 wk caused increased sympathetic predominance in heart rate variability measurements. In vivo inducible ventricular tachycardia was significantly longer, and in optical mapping, the magnitude of ventricular action potential duration alternans was significantly larger in the vanillin aldehyde-flavored e-vapor-exposed mice than in controls. We conclude that the widely popular flavored ENDS are not harm free, and they have a potential for cardiac harm. More studies are needed to further assess their cardiac safety profile and long-term health effects.NEW & NOTEWORTHY The use of electronic nicotine delivery systems (ENDS) is not harm free. It is not known whether ENDS negatively affect cardiac electrophysiological function. Our study in cell lines and in mice shows that ENDS can compromise cardiac electrophysiology, leading to action potential instability and inducible ventricular arrhythmias. Further investigations are necessary to assess the long-term cardiac safety profile of ENDS products in humans and to better understand how individual components of ENDS affect cardiac toxicity.
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Affiliation(s)
- Obada Abouassali
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Mengmeng Chang
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Bojjibabu Chidipi
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | | | - Michelle Reiser
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Manasa Kanithi
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Ravi Soni
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Thomas V McDonald
- Division of Cardiology, Department of Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Bengt Herweg
- Division of Cardiology, Department of Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Javier Saiz
- Ci2 B, Universitat Politècnica de València, Valencia, Spain
| | - Laurent Calcul
- Department of Chemistry, College of Arts and Sciences, University of South Florida, Tampa, Florida
| | - Sami F Noujaim
- Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
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38
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Omaiye EE, Luo W, McWhirter KJ, Pankow JF, Talbot P. Electronic Cigarette Refill Fluids Sold Worldwide: Flavor Chemical Composition, Toxicity, and Hazard Analysis. Chem Res Toxicol 2020; 33:2972-2987. [PMID: 33225688 PMCID: PMC8166200 DOI: 10.1021/acs.chemrestox.0c00266] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Flavor chemicals in electronic cigarette (EC) fluids, which may negatively impact human health, have been studied in a limited number of countries/locations. To gain an understanding of how the composition and concentrations of flavor chemicals in ECs are influenced by product sale location, we evaluated refill fluids manufactured by one company (Ritchy LTD) and purchased worldwide. Flavor chemicals were identified and quantified using gas chromatography/mass spectrometry (GC/MS). We then screened the fluids for their effects on cytotoxicity (MTT assay) and proliferation (live-cell imaging) and tested authentic standards of specific flavor chemicals to identify those that were cytotoxic at concentrations found in refill fluids. A total of 126 flavor chemicals were detected in 103 bottles of refill fluid, and their number per/bottle ranged from 1-50 based on our target list. Two products had none of the flavor chemicals on our target list, nor did they have any nontargeted flavor chemicals. A total of 28 flavor chemicals were present at concentrations ≥1 mg/mL in at least one product, and 6 of these were present at concentrations ≥10 mg/mL. The total flavor chemical concentration was ≥1 mg/mL in 70% of the refill fluids and ≥10 mg/mL in 26%. For sub-brand duplicate bottles purchased in different countries, flavor chemical concentrations were similar and induced similar responses in the in vitro assays (cytotoxicity and cell growth inhibition). The levels of furaneol, benzyl alcohol, ethyl maltol, ethyl vanillin, corylone, and vanillin were significantly correlated with cytotoxicity. The margin of exposure calculations showed that pulegone and estragole levels were high enough in some products to present a nontrivial calculated risk for cancer. Flavor chemical concentrations in refill fluids often exceeded concentrations permitted in other consumer products. These data support the regulation of flavor chemicals in EC products to reduce their potential for producing both cancer and noncancer toxicological effects.
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Affiliation(s)
- Esther E. Omaiye
- Environmental Toxicology Graduate Program, University of California Riverside, California, USA
- Department of Molecular, Cell, and Systems Biology. University of California, Riverside, California, USA
| | - Wentai Luo
- Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
- Department of Chemistry Portland State University. Portland, Oregon, USA
| | - Kevin J. McWhirter
- Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
| | - James F. Pankow
- Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
- Department of Chemistry Portland State University. Portland, Oregon, USA
| | - Prue Talbot
- Department of Molecular, Cell, and Systems Biology. University of California, Riverside, California, USA
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39
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Kaur G, Gaurav A, Lamb T, Perkins M, Muthumalage T, Rahman I. Current Perspectives on Characteristics, Compositions, and Toxicological Effects of E-Cigarettes Containing Tobacco and Menthol/Mint Flavors. Front Physiol 2020; 11:613948. [PMID: 33329065 PMCID: PMC7710937 DOI: 10.3389/fphys.2020.613948] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 10/23/2020] [Indexed: 11/13/2022] Open
Abstract
Electronic nicotine delivery systems/devices (ENDS) such as electronic cigarettes (e-cigarettes) have been made available globally, with the intent to reduce tobacco smoking. To make these products more appealing to young adults, many brands have added flavoring agents. However, these flavoring agents are shown to progressively result in lung toxicity when inhaled via e-cigarettes. While recent federal regulations have banned the sale of flavored e-cigarettes other than tobacco or menthol flavors, concerns have been raised about the health effects of even these flavors. In this review, we evaluate the current toxicological data with regard to effects upon exposure in animal models and in vitro cell culture for these popular flavorants. We have tabulated the current e-cigarette products containing these most common flavors (menthol, mint, and tobacco) in the market. We have also indicated the prevalence of tobacco and menthol-flavor use among e-cigarette users and highlighted the possible challenges and benefits that will result from new federal regulations.
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Affiliation(s)
- Gurjot Kaur
- School of Pharmaceutical Sciences, Shoolini University, Solan, India
| | - Anshuman Gaurav
- School of Pharmaceutical Sciences, Shoolini University, Solan, India
| | - Thomas Lamb
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Melanie Perkins
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Thivanka Muthumalage
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
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40
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Correia-Álvarez E, Keating JE, Glish G, Tarran R, Sassano MF. Reactive Oxygen Species, Mitochondrial Membrane Potential, and Cellular Membrane Potential Are Predictors of E-Liquid Induced Cellular Toxicity. Nicotine Tob Res 2020; 22:S4-S13. [PMID: 33320253 PMCID: PMC8493666 DOI: 10.1093/ntr/ntaa177] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 09/08/2020] [Indexed: 12/22/2022]
Abstract
Introduction The use of flavors in electronic cigarettes appeals to adults and
never-smoking youth. Consumption has rapidly increased over the last decade,
and in the U.S. market alone, there are over 8000 unique flavors. The U.S.
Food and Drug Administration (FDA) has begun to regulate e-liquids, but many
have not been tested, and their impact, both at the cellular level, and on
human health remains unclear. Methods We tested e-liquids on the human cell line HEK293T and measured toxicity,
mitochondrial membrane potential
(ΔΨ m), reactive oxygen species
production (ROS), and cellular membrane potential
(Vm) using high-throughput screening (HTS)
approaches. Our HTS efforts included single-dose and 16-point
dose–response curves, which allowed testing of ≥90
commercially available e-liquids in parallel to provide a rapid assessment
of cellular effects as a proof of concept for a fast, preliminary toxicity
method. We also investigated the chemical composition of the flavors via gas
chromatography–mass spectrometry. Results We found that e-liquids caused a decrease in
ΔΨ m and
Vm and an increase in ROS production and
toxicity in a dose-dependent fashion. In addition, the presence of five
specific chemical components: vanillin, benzyl alcohol, acetoin,
cinnamaldehyde, and methyl-cyclopentenolone, but not nicotine, were linked
with the changes observed in the cellular traits studied. Conclusion Our data suggest that ΔΨ m, ROS,
Vm, and toxicity may be indicative of the
extent of cell death upon e-liquid exposure. Further research on the effect
of flavors should be prioritized to help policy makers such as the FDA to
regulate e-liquid composition. Implications E-liquid cellular toxicity can be predicted using parameters amenable to HTS.
Our data suggest that ΔΨ m, ROS,
Vm, and toxicity may be indicative of the
extent of cell death upon e-liquid exposure, and this toxicity is linked to
the chemical composition, that is, flavoring components. Further research on
the effect of flavors should be prioritized to help policy makers such as
the FDA to regulate e-liquid composition.
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Affiliation(s)
- Eva Correia-Álvarez
- Department of Cell Biology and Physiology, University of North
Carolina, Chapel Hill, NC
| | - James E Keating
- Department of Chemistry, University of North Carolina,
Chapel Hill, NC
| | - Gary Glish
- Department of Chemistry, University of North Carolina,
Chapel Hill, NC
| | - Robert Tarran
- Department of Cell Biology and Physiology, University of North
Carolina, Chapel Hill, NC
| | - M Flori Sassano
- Department of Cell Biology and Physiology, University of North
Carolina, Chapel Hill, NC
- Corresponding Author: M. Flori Sassano, PhD, Department of Cell
Biology and Physiology, University of North Carolina 115 Mason Farm Road, Chapel
Hill, NC 27599-7544, USA. Telephone: 919-966-7053; Fax: 919-966-6927; E-mail:
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41
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Ween MP, Moshensky A, Thredgold L, Bastian NA, Hamon R, Badiei A, Nguyen PT, Herewane K, Jersmann H, Bojanowski CM, Shin J, Reynolds PN, Crotty Alexander LE, Hodge SJ. E-cigarettes and health risks: more to the flavor than just the name. Am J Physiol Lung Cell Mol Physiol 2020; 320:L600-L614. [PMID: 33295836 DOI: 10.1152/ajplung.00370.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The growing interest in regulating flavored E-liquids must incorporate understanding of the "flavoring profile" of each E-liquid-which flavorings (flavoring chemicals) are present and at what concentrations not just focusing on the flavor on the label. We investigated the flavoring profile of 10 different flavored E-liquids. We assessed bronchial epithelial cell viability and apoptosis, phagocytosis of bacteria and apoptotic cells by macrophages after exposure to E-cigarette vapor extract (EVE). We validated our data in normal human bronchial epithelial cells (NHBE) and alveolar macrophages (AM) from healthy donors. We also assessed cytokine release and validated in the saliva from E-cigarette users. Increased necrosis/apoptosis (16.1-64.5% apoptosis) in 16HBE cells was flavor dependent, and NHBEs showed an increased susceptibility to flavors. In THP-1 differentiated macrophages phagocytosis was also flavor dependent, with AM also showing increased susceptibility to flavors. Further, Banana and Chocolate were shown to reduce surface expression of phagocytic target recognition receptors on alveolar macrophages. Banana and Chocolate increased IL-8 secretion by NHBE, whereas all 4 flavors reduced AM IL-1β secretion, which was also reduced in the saliva of E-cigarette users compared with healthy controls. Flavorant profiles of E-liquids varied from simple 2 compound mixtures to complex mixtures containing over a dozen flavorants. E-liquids with high benzene content, complex flavoring profiles, high chemical concentration had the greatest impacts. The Flavorant profile of E-liquids is key to disruption of the airway status quo by increasing bronchial epithelial cell apoptosis, causing alveolar macrophage phagocytic dysfunction, and altering airway cytokines.
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Affiliation(s)
- M P Ween
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - A Moshensky
- Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System, San Diego, California.,Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, California
| | - L Thredgold
- Department of Occupational and Environmental Health, School of Public Health, University of Adelaide, Adelaide, South Australia, Australia
| | - N A Bastian
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - R Hamon
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,Centre for Cancer Biology, SA Pathology and the University of South Australia, Adelaide, South Australia, Australia
| | - A Badiei
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - P T Nguyen
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - K Herewane
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - H Jersmann
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - C M Bojanowski
- Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System, San Diego, California.,Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, California
| | - J Shin
- Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System, San Diego, California.,Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, California
| | - P N Reynolds
- Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
| | - L E Crotty Alexander
- Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System, San Diego, California.,Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, La Jolla, California
| | - S J Hodge
- School of Medicine, University of Adelaide, Adelaide, South Australia, Australia
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42
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Woodall M, Jacob J, Kalsi KK, Schroeder V, Davis E, Kenyon B, Khan I, Garnett JP, Tarran R, Baines DL. E-cigarette constituents propylene glycol and vegetable glycerin decrease glucose uptake and its metabolism in airway epithelial cells in vitro. Am J Physiol Lung Cell Mol Physiol 2020; 319:L957-L967. [PMID: 32996783 PMCID: PMC7792687 DOI: 10.1152/ajplung.00123.2020] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/11/2020] [Accepted: 09/11/2020] [Indexed: 02/07/2023] Open
Abstract
Electronic nicotine delivery systems, or e-cigarettes, utilize a liquid solution that normally contains propylene glycol (PG) and vegetable glycerin (VG) to generate vapor and act as a carrier for nicotine and flavorings. Evidence indicated these "carriers" reduced growth and survival of epithelial cells including those of the airway. We hypothesized that 3% PG or PG mixed with VG (3% PG/VG, 55:45) inhibited glucose uptake in human airway epithelial cells as a first step to reducing airway cell survival. Exposure of H441 or human bronchiolar epithelial cells (HBECs) to PG and PG/VG (30-60 min) inhibited glucose uptake and mitochondrial ATP synthesis. PG/VG inhibited glycolysis. PG/VG and mannitol reduced cell volume and height of air-liquid interface cultures. Mannitol, but not PG/VG, increased phosphorylation of p38 MAPK. PG/VG reduced transepithelial electrical resistance, which was associated with increased transepithelial solute permeability. PG/VG decreased fluorescence recovery after photobleaching of green fluorescent protein-linked glucose transporters GLUT1 and GLUT10, indicating that glucose transport function was compromised. Puffing PG/VG vapor onto the apical surface of primary HBECs for 10 min to mimic the effect of e-cigarette smoking also reduced glucose transport. In conclusion, short-term exposure to PG/VG, key components of e-cigarettes, decreased glucose transport and metabolism in airway cells. We propose that this was a result of PG/VG reduced cell volume and membrane fluidity, with further consequences on epithelial barrier function. Taking these results together, we suggest these factors contribute to reduced defensive properties of the epithelium. We propose that repeated/chronic exposure to these agents are likely to contribute to airway damage in e-cigarette users.
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Affiliation(s)
- M. Woodall
- Institute for Infection and Immunity, St George’s, University of London, Tooting, London, United Kingdom
| | - J. Jacob
- Institute for Infection and Immunity, St George’s, University of London, Tooting, London, United Kingdom
| | - K. K. Kalsi
- Institute for Infection and Immunity, St George’s, University of London, Tooting, London, United Kingdom
| | - V. Schroeder
- Immunology and Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - E. Davis
- Marsico Lung Institute and Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina
| | - B. Kenyon
- Marsico Lung Institute and Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina
| | - I. Khan
- Institute for Infection and Immunity, St George’s, University of London, Tooting, London, United Kingdom
| | - J. P. Garnett
- Immunology and Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - R. Tarran
- Marsico Lung Institute and Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina
| | - D. L. Baines
- Institute for Infection and Immunity, St George’s, University of London, Tooting, London, United Kingdom
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43
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Wills TA, Soneji SS, Choi K, Jaspers I, Tam EK. E-cigarette use and respiratory disorders: an integrative review of converging evidence from epidemiological and laboratory studies. Eur Respir J 2020. [PMID: 33154031 DOI: 10.1183/13993003.01815‐2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Use of electronic cigarettes (e-cigarettes) is prevalent among adolescents and young adults, but there has been limited knowledge about health consequences in human populations. We conduct a systematic review and meta-analysis of results on respiratory disorders from studies of general-population samples and consider the mapping of these results to findings about biological processes linked to e-cigarettes in controlled laboratory studies. METHOD We conducted a literature search and meta-analysis of epidemiological studies on the association of e-cigarette use with asthma and with COPD. We discuss findings from laboratory studies about effects of e-cigarettes on four biological processes: cytotoxicity, oxidative stress/inflammation, susceptibility to infection and genetic expression. RESULTS Epidemiological studies, both cross-sectional and longitudinal, show a significant association of e-cigarette use with asthma and COPD, controlling for cigarette smoking and other covariates. For asthma (n=15 studies), the pooled adjusted odds ratio (aOR) was 1.39 (95% CI 1.28-1.51); for COPD (n=9 studies) the aOR was 1.49 (95% CI 1.36-1.65). Laboratory studies consistently show an effect of e-cigarettes on biological processes related to respiratory harm and susceptibility to illness, with e-cigarette conditions differing significantly from clean-air controls, although sometimes less than for cigarettes. CONCLUSIONS The evidence from epidemiological studies meets established criteria for consistency, strength of effect, temporality, and in some cases a dose-response gradient. Biological plausibility is indicated by evidence from multiple laboratory studies. We conclude that e-cigarette use has consequences for asthma and COPD, which is of concern for respirology and public health.
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Affiliation(s)
- Thomas A Wills
- Cancer Prevention Program, University of Hawaii Cancer Center, Honolulu, HI, USA
| | - Samir S Soneji
- Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Kelvin Choi
- Division of Intramural Research, National Institute on Minority Health and Health Disparities, Bethesda, MD, USA
| | - Ilona Jaspers
- Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Elizabeth K Tam
- Dept of Medicine, John A. Burns School of Medicine, Honolulu, HI, USA
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44
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Ghosh A, Beyazcicek O, Davis ES, Onyenwoke RU, Tarran R. Cellular effects of nicotine salt-containing e-liquids. J Appl Toxicol 2020; 41:493-505. [PMID: 33034066 DOI: 10.1002/jat.4060] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 12/30/2022]
Abstract
"Pod-based" e-cigarettes such as JUUL are currently the most prevalent electronic nicotine delivery systems (ENDS) in the United States. JUUL-type ENDS utilize nicotine salts protonated with benzoic acid rather than freebase nicotine. However, limited information is available on the cellular effects of these products. Cytoplasmic Ca2+ is a universal second messenger that controls many cellular functions including cell growth and cell death. Of note, dysregulation of cell Ca2+ homeostasis has been linked with several disease processes including autoimmune disease and several types of cancer. We exposed HEK293T cells and THP-1 macrophage-like cells to different JUUL e-liquids. We evaluated their effects on cellular viability and Ca2+ signaling by measuring fluorescence from calcein-AM/propidium iodide and Fluo-4, respectively. E-liquid autofluorescence was used to look for e-liquid permeation into cells. To identify the mechanisms behind the Ca2+ responses, different inhibitors of Ca2+ channels and phospholipase C signaling were used. JUUL e-liquids caused significant cytotoxic effects, with "Mint" flavor being the most cytotoxic. The Mint flavored e-liquid also caused a significant elevation in cytoplasmic Ca2+ . Using autofluorescence, the permeation of JUUL e-liquids into live cells was confirmed, indicating that intracellular organelles are directly exposed to e-liquids. Further studies identified the endoplasmic reticulum as being the source of e-liquid-induced changes in cytoplasmic Ca2+ . Nicotine salt-based e-liquids cause cytotoxicity and elevate cytoplasmic Ca2+ , indicating that they can exert biological effects beyond what would be expected with nicotine alone. These effects are flavor-dependent, and we propose that flavored e-liquids be reassessed for potential lung toxicity.
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Affiliation(s)
- Arunava Ghosh
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ozge Beyazcicek
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Eric S Davis
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rob U Onyenwoke
- Biomanufacturing Research Institute and Technology Enterprise, North Carolina Central University, Durham, North Carolina, USA
| | - Robert Tarran
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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45
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Wills TA, Choi K, Pagano I. E-Cigarette Use Associated With Asthma Independent of Cigarette Smoking and Marijuana in a 2017 National Sample of Adolescents. J Adolesc Health 2020; 67:524-530. [PMID: 32336559 PMCID: PMC8248447 DOI: 10.1016/j.jadohealth.2020.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/15/2020] [Accepted: 03/03/2020] [Indexed: 02/06/2023]
Abstract
PURPOSE Knowledge about the health consequences of e-cigarette use in adolescence remains limited. Available studies of asthma among adolescents are based on data collected five or more years ago, and evidence from more recent generations of e-cigarette products is needed. METHODS We analyzed data from the 2017 Youth Risk Behavior Survey, a cross-sectional study with a representative U.S. national sample of high school students. Multivariable analyses tested for associations of ever and 30-day e-cigarette use with asthma controlling for cigarette smoking, marijuana use, demographics, and obesity. RESULTS A significant association with asthma was found for ever use of e-cigarettes, adjusted odds ratio (AOR) = 1.15 (confidence interval [CI], 1.02-1.30; p = .02) and for currently using e-cigarettes, AOR = 1.30 (CI, 1.10-1.53; p = .002). Also related to asthma were current cigarette smoking, AOR = 1.24 (CI, 1.03-1.51; p = .03) and obesity, AOR = 1.48 (CI, 1.30-1.68; p < .0001). E-cigarettes had an additive effect for asthma beyond smoking (p = .03). Differentials in asthma prevalence by race/ethnicity were found, with lower prevalence of asthma for non-Hispanic Asian (p = .02) and Hispanic (p = .03) and higher prevalence for non-Hispanic black (p < .0001) and non-Hispanic multirace (p < .0001) relative to non-Hispanic white populations. CONCLUSIONS E-cigarette use was significantly associated with asthma in recent data on adolescents, controlling for several disease-relevant covariates. The results are consistent with studies based on previous generations of e-cigarettes and support the significance of e-cigarettes as a continuing public health concern.
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Affiliation(s)
- Thomas A Wills
- Cancer Prevention Program, University of Hawaii Cancer Center, Honolulu, Hawaii.
| | - Kelvin Choi
- Division of Intramural Research, National Institute on Minority Health and Health Disparities, Bethesda, Maryland
| | - Ian Pagano
- Cancer Prevention Program, University of Hawaii Cancer Center, Honolulu, Hawaii
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Affiliation(s)
- Sylvia Knapp
- Department of Medicine 1 Medical University of Vienna Vienna, Austria
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The flavoring and not the nicotine content is a decisive factor for the effects of refill liquids of electronic cigarette on the redox status of endothelial cells. Toxicol Rep 2020; 7:1095-1102. [PMID: 32953462 PMCID: PMC7484539 DOI: 10.1016/j.toxrep.2020.08.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 11/21/2022] Open
Abstract
The pattern of the effect on Ea.hy926 redox status differs among flavored e-liquids. Tobacco flavored e-liquids increase ROS generation with concomitant increase in TBARS. Vanilla flavored e-liquids profile depends on the nicotine content. Apple/mint flavored e-liquids activate the cellular antioxidant defense. Flavorings and not the nicotine content play a key role in free radical generation.
Electronic cigarettes are constantly gaining ground as they are considered less harmful than conventional cigarettes, and there is also the perception that they may serve as a potential smoking cessation tool. Although the acute effects of electronic cigarette use have been extensively studied, the long-term potential adverse effects on human health remain largely unknown. It has been well-established that oxidative stress is involved in the development of various pathological conditions. So far, most studies on e-cigarettes concern the effects on the respiratory system while fewer have focused on the vascular system. In the present study, we attempted to reveal the effects of electronic cigarette refill liquids on the redox state of human endothelial cells (EA.hy926 cell line). For this purpose, the cytotoxic effect of three e-liquids with different flavors (tobacco, vanilla, apple/mint) and nicotine concentrations (0, 6, 12, 18 mg/ml) were initially examined for their impact on cell viability of EA.hy926 cells. Then, five redox biomarkers [reduced form of glutathione (GSH), reactive oxygen species (ROS), total antioxidant capacity (TAC), thiobarbituric acid reactive substances (TBARS) and protein carbonyls (CARBS)] were measured. The results showed a disturbance in the redox balance in favor of free radicals in tobacco flavored e-liquids while vanilla flavored e-liquids exhibited a more complex profile depending on the nicotine content. The most interesting finding of the present study concerns the apple/mint flavored e-liquids that seemed to activate the cellular antioxidant defense and, thus, to protect the cells from the adverse effects of free radicals. Conclusively, it appears that the flavorings and not the nicotine content play a key role in the oxidative stress-induced toxicity of the e-liquids.
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Key Words
- 8-OH-dG, 8-hydroxy-deoxyguanosine
- CARBS, protein carbonyls
- CO, carbon monoxide
- DCF-DA, 2′,7′-dichlorodihydrofluorescein diacetate
- DMEM, Dulbecco’s modified Eagle’s medium
- DNPH, 2,4-dinitrophenylhydrazine
- DPPH, 2,2-diphenyl-1-picrylhydrazyl
- DPPHH, 2,2-diphenyl-1-picrylhydrazine
- E-cigarettes
- E-liquids
- ENDS, electronic nicotine delivery systems
- EPR, electronic paramagnetic resonance
- Endothelial cells
- FSC, forward light scattering
- GSH
- GSH, reduced form of glutathione
- HCL, hydrochloric acid
- HCN, hydrogen cyanide
- MDA, malondialdehyde
- Oxidative stress
- PBS, phosphate buffered saline
- PG, propylene glycol
- ROS
- ROS, reactive oxygen species
- SSC, side light scattering
- TAC, total antioxidant capacity
- TBA, thiobarbituric acid
- TBARS, thiobarbituric acid reactive substances
- TCA, trichloroacetic acid
- Tris-HCl, trishydroxymethylaminomethane hydrochloride
- VG, vegetable glycerin
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Escobar YNH, Nipp G, Cui T, Petters SS, Surratt JD, Jaspers I. In Vitro Toxicity and Chemical Characterization of Aerosol Derived from Electronic Cigarette Humectants Using a Newly Developed Exposure System. Chem Res Toxicol 2020; 33:1677-1688. [PMID: 32223225 DOI: 10.1021/acs.chemrestox.9b00490] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In the United States, the recent surge of electronic cigarette (e-cig) use has raised questions concerning the safety of these devices. This study seeks to assess the pro-inflammatory and cellular stress effects of the vaped humectants propylene glycol (PG) and glycerol (GLY) on airway epithelial cells (16HBE cells and differentiated human bronchial epithelial cells) with a newly developed aerosol exposure system. This system allows for chemical characterization of e-cig generated aerosol particles as well as in vitro exposures of 16HBE cells at an air-liquid interface to vaped PG and GLY aerosol. Our data demonstrate that the process of vaping results in the formation of PG- and GLY-derived oligomers in the aerosol particles. Our in vitro data demonstrate an increase in pro-inflammatory cytokines IL-6 and IL-8 levels in response to vaped PG and GLY exposures. Vaped GLY also causes an increase in cellular stress signals HMOX1, NQO1, and carbonylated proteins when the e-cig device is operated at high wattages. Additionally, we find that the exposure of vaped PG causes elevated IL-6 expression, while the exposure of vaped GLY increases HMOX1 expression in human bronchial epithelial cells when the device is operated at high wattages. These findings suggest that vaporizing PG and GLY results in the formation of novel compounds and the exposure of vaped PG and GLY are detrimental to airway cells. Since PG and/or GLY is universally contained in all e-cig liquids, we conclude that these components alone can cause harm to the airway epithelium.
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Affiliation(s)
| | - Grace Nipp
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, North Carolina 27599, United States
| | - Tianqu Cui
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, North Carolina 27599, United States
| | - Sarah S Petters
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, North Carolina 27599, United States
| | - Jason D Surratt
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, North Carolina 27599, United States
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Lavacchi D, Roviello G, Rodriquenz MG. Electronic nicotine delivery systems (ENDS): not still ready to put on END. J Thorac Dis 2020; 12:3857-3865. [PMID: 32802467 PMCID: PMC7399423 DOI: 10.21037/jtd.2019.12.124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In recent years, the marketing of electronic nicotine delivery systems (ENDS) has changed the attitudes of people towards tobacco products. In addition, ENDS are becoming very popular among youth. Since a high percentage of young people use these delivery systems as the first products containing nicotine, the acute and chronic exposure to ENDS emissions and nicotine-induced effects on the adolescent's brain deserve a special attention. Given the extremely varied types of ENDS and the heterogeneous concentrations of substances emitted by specific devices, an overall risk assessment is particularly difficult. Here we critically review the evidence on the safety profile of ENDS, we also discuss the global policies with the leading role of the World Health Organization (WHO), which provides updated information and indications that must guide community and individual choices.
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Affiliation(s)
- Daniele Lavacchi
- School of Human Health Sciences, University of Florence, Florence, Italy
| | | | - Maria Grazia Rodriquenz
- Division of Medical Oncology, Department of Onco-Hematology, IRCCS-CROB, Referral Cancer Center of Basilicata, Rionero, Vulture, PZ, Italy
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Ebersole J, Samburova V, Son Y, Cappelli D, Demopoulos C, Capurro A, Pinto A, Chrzan B, Kingsley K, Howard K, Clark N, Khlystov A. Harmful chemicals emitted from electronic cigarettes and potential deleterious effects in the oral cavity. Tob Induc Dis 2020; 18:41. [PMID: 32435175 PMCID: PMC7233525 DOI: 10.18332/tid/116988] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/20/2019] [Accepted: 01/22/2020] [Indexed: 12/29/2022] Open
Abstract
Use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes (e-cigs), is increasing across the US population and is particularly troubling due to their adoption by adolescents, teens, and young adults. The industry’s marketing approach for these instruments of addiction has been to promote them as a safer alternative to tobacco, a behavioral choice supporting smoking cessation, and as the ‘cool’ appearance of vaping with flavored products (e.g. tutti frutti, bubble gum, and buttered popcorn etc.). Thus, there is a clear need to better document the health outcomes of e-cig use in the oral cavity of the addicted chronic user. There appears to be an array of environmental toxins in the vapors, including reactive aldehydes and carbonyls resulting from the heating elements action on fluid components, as well as from the composition of chemical flavoring agents. The chemistry of these systems shows that the released vapors from the e-cigs frequently contain levels of environmental toxins that considerably exceed federal occupational exposure limits. Additionally, the toxicants in the vapors appear to be retained in the host fluids/tissues at levels often approximating 90% of the levels in the e-cig vapors. These water-soluble reactive toxins can challenge the oral cavity constituents, potentially contributing to alterations in the autochthonous microbiome and host cells critical for maintaining oral homeostasis. This review updates the existing chemistry/environmental aspects of e-cigs, as well as providing an overview of the somewhat limited data on potential oral health effects that could occur across the lifetime of daily e-cig users.
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Affiliation(s)
- Jeffrey Ebersole
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Vera Samburova
- Organic Analytical Laboratory, Division of Atmospheric Sciences, Desert Research Institute, Reno, United States
| | - Yeongkwon Son
- Organic Analytical Laboratory, Division of Atmospheric Sciences, Desert Research Institute, Reno, United States
| | - David Cappelli
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Christina Demopoulos
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Antonina Capurro
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Andres Pinto
- Oral and Maxillofacial Medicine and Diagnostic Sciences, School of Dental Medicine, Case Western University, Cleveland, United States
| | - Brian Chrzan
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Karl Kingsley
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Katherine Howard
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Nathaniel Clark
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
| | - Andrey Khlystov
- Department of Biomedical Sciences, School of Dental Medicine, University of Nevada Las Vegas, Las Vegas, United States
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