1
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Ito H, Shigeto A, Hashizume T. A solvent-free squeezing method for extraction of collected mass from aerosols of electronic cigarettes and heated tobacco products. J Chromatogr A 2024; 1727:465009. [PMID: 38776605 DOI: 10.1016/j.chroma.2024.465009] [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: 12/29/2023] [Revised: 05/10/2024] [Accepted: 05/17/2024] [Indexed: 05/25/2024]
Abstract
Previous in vitro toxicological assessments have demonstrated that almost no mutagenic and genotoxic activities in electronic cigarette (e-cigarette) and heated tobacco product (HTP) aerosols were detected even at the maximum recommended concentration. To accurately compare the toxicity levels between cigarette smoke and e-cigarette or HTP aerosols, higher exposure concentrations increasing the possibility to detect toxicity in in vitro tests are necessary, while avoiding solvent-induced toxicity. This study aimed to develop a solvent-free extraction method to obtain concentrated aerosol extracts for improved toxicological evaluation. Our novel approach involved squeezing several Cambridge filter pads, which collected aerosol constituents, in closed containers to achieve solvent-free extraction with comparable efficiency to the conventional method using organic solvents. The optimized squeezing method yielded extracts with concentrations approximately 10 times higher than those obtained in conventional extraction methods. Yield comparison of various constituents, such as flavoring compounds, in e-cigarette aerosol extracts revealed similar extraction efficiencies between the squeezing and conventional methods. However, the extraction efficiency for constituents with high log Pow values, predominantly found in HTP aerosol extracts, was unacceptably low using the squeezing method. In addition, solvent-free centrifuging, another type of extraction method, exhibited unsatisfactory results for even e-cigarette aerosols compared with the conventional method. Our findings suggest that the solvent-free squeezing method is suitable for extracting aerosol collected mass from e-cigarette aerosol but not from HTP aerosol. We anticipate that the solvent-free squeezing method will contribute to a deeper understanding of toxicological differences between e-cigarettes and conventional combustible cigarettes.
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Affiliation(s)
- Hiroshi Ito
- Scientific Product Assessment Center, R&D group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan
| | - Atsushi Shigeto
- Scientific Product Assessment Center, R&D group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan
| | - Tsuneo Hashizume
- Scientific Product Assessment Center, R&D group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan.
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2
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Fu F, Li X, Chen Y, Li L, Dou J, Liang K, Chen Y, Lu Y, Huang Y. Genotoxicity and cytotoxicity evaluation of a heat-not-burn product. MUTATION RESEARCH. GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2024; 897:503784. [PMID: 39054007 DOI: 10.1016/j.mrgentox.2024.503784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/26/2024] [Accepted: 05/27/2024] [Indexed: 07/27/2024]
Abstract
'Heat-not-burn' products (HnBP) contain lower levels of harmful substances than traditional cigarettes, but the use of these products warrants further toxicological evaluation. We have compared the cytotoxicity and genotoxicity of a heat-not burn product with conventional cigarettes, in vivo and in vitro. Male Sprague Dawley rats were exposed to mainstream smoke from conventional cigarettes or a HnBP, for 4 or 28 days, followed by isolation of bone marrow polychromatic erythrocytes (PCE) and histological examination of the testes. Chinese hamster lung fibroblast cells were exposed in vitro to total particulate matter from cigarette smoke obtained through Cambridge filters. The cytotoxicity and genotoxicity of total particulate matter were assessed by the neutral red uptake assay, chromosome aberration assay, in vitro micronucleus test, comet assay, and Ames assay. In the short-term exposure rat models, only the conventional-cigarettes group showed a significant increase in the ratio of micronuclei to total PCE. There was no significant difference in rat testis histology in the long-term exposure models. In vitro, in the neutral red uptake assay, the HnBP product showed lower cytotoxicity than conventional cigarettes. Conventional cigarettes showed greater genotoxicity in the chromosome aberration assay, high-dose Ames tests with exogenous metabolic activation, and micronucleus tests. In summary, our results suggest that HnBP have lower cytotoxicity and genotoxicity than conventional cigarettes.
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Affiliation(s)
- Fudong Fu
- Department of Pulmonary and Critical Care Medicine, and Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaoyu Li
- Department of Pulmonary and Critical Care Medicine, and Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China
| | - Younan Chen
- Department of Pulmonary and Critical Care Medicine, and Institutes for Systems Genetics, Frontiers Science Center for Disease-related Molecular Network, West China Hospital, Sichuan University, Chengdu, China; Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - Lan Li
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiexiong Dou
- Sichuan Center for Disease Control and Prevention, Chengdu 610044, China
| | - Kun Liang
- Harmful Components and Tar Reduction in Cigarette Key Laboratory of Sichuan Province, Chengdu 610101, China; New Tobacco Products Engineering and Technology Research Center of Sichuan Province, Chengdu 610101 China
| | - Yexian Chen
- Harmful Components and Tar Reduction in Cigarette Key Laboratory of Sichuan Province, Chengdu 610101, China; New Tobacco Products Engineering and Technology Research Center of Sichuan Province, Chengdu 610101 China
| | - Yanrong Lu
- Key Laboratory of Transplant Engineering and Immunology, NHFPC, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yuchuan Huang
- Harmful Components and Tar Reduction in Cigarette Key Laboratory of Sichuan Province, Chengdu 610101, China; New Tobacco Products Engineering and Technology Research Center of Sichuan Province, Chengdu 610101 China.
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3
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Fearon IM, Cordery SF, Fitzpatrick M, Weaver S, Stevenson M, Grandolfo E, Malt L, Thompson K, Nahde T. A Scoping Review of Behavioural Studies on Heated Tobacco Products. Cureus 2024; 16:e65773. [PMID: 39211653 PMCID: PMC11361622 DOI: 10.7759/cureus.65773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2024] [Indexed: 09/04/2024] Open
Abstract
Heated tobacco products (HTPs) are electronic devices that heat tobacco sticks to temperatures much lower than those which cause pyrolysis and combustion in cigarettes. While this electrical heating causes the formation of an inhalable aerosol which contains nicotine, the aerosol from HTPs contains significantly fewer and lower levels of the harmful and potentially harmful chemicals found in cigarette smoke. As a result, HTP use potentially conveys reduced risks to health compared to cigarette smoking. While this relative reduction in individual health risk is becoming clearer, what is less certain is the impact of HTPs on overall population‑level health, taking into account both the potential positive impact on adult smokers who completely switch to using HTPs and any unintended impacts such as use by tobacco non‑users and particularly by youth. The aim of this scoping review was to collate and evaluate the published scientific evidence to date, with a cut‑off of 1 January 2024, investigating the impact of HTPs on population‑level health. This evaluation suggests that HTP use is almost exclusively observed among those with a history of cigarette smoking, and there is a growing body of evidence for the ability of HTPs to provide support for adult smokers to transition away from cigarette smoking, in the absence of any significant "gateway" into tobacco use initiation. Many studies have reported a significant degree of dual use of cigarettes and HTPs, and efforts to assess the reasons for such patterns of use, whether these provide overall exposure reductions, and whether dual use acts as a bridge towards a complete transition away from cigarette smoking, requires further investigation. In addition, correction of the widespread and increasing misperceptions of HTPs among adult smokers is recommended to promote HTP uptake as a potentially less harmful alternative to smoking in this population.
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Affiliation(s)
- Ian M Fearon
- Scientific Research, whatIF? Consulting Ltd., Harwell, GBR
| | - Sarah F Cordery
- Group Science and Regulatory Affairs, Imperial Brands PLC, Bristol, GBR
| | | | - Sarah Weaver
- Group Science and Regulatory Affairs, Imperial Brands PLC, Bristol, GBR
| | - Matthew Stevenson
- Group Science and Regulatory Affairs, Imperial Brands PLC, Bristol, GBR
| | - Erika Grandolfo
- Group Science and Regulatory Affairs, Imperial Brands PLC, Bristol, GBR
| | - Layla Malt
- Group Science and Regulatory Affairs, Imperial Brands PLC, Bristol, GBR
| | - Keith Thompson
- Scientific Consultant, Elucid8 Holdings Ltd., Newtownabbey, GBR
| | - Thomas Nahde
- Group Science and Regulatory Affairs, Imperial Brands Reemtsma, Hamburg, DEU
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4
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Thorne D, McHugh D, Simms L, Lee KM, Fujimoto H, Moses S, Gaca M. Applying new approach methodologies to assess next-generation tobacco and nicotine products. FRONTIERS IN TOXICOLOGY 2024; 6:1376118. [PMID: 38938663 PMCID: PMC11208635 DOI: 10.3389/ftox.2024.1376118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/30/2024] [Indexed: 06/29/2024] Open
Abstract
In vitro toxicology research has accelerated with the use of in silico, computational approaches and human in vitro tissue systems, facilitating major improvements evaluating the safety and health risks of novel consumer products. Innovation in molecular and cellular biology has shifted testing paradigms, with less reliance on low-throughput animal data and greater use of medium- and high-throughput in vitro cellular screening approaches. These new approach methodologies (NAMs) are being implemented in other industry sectors for chemical testing, screening candidate drugs and prototype consumer products, driven by the need for reliable, human-relevant approaches. Routine toxicological methods are largely unchanged since development over 50 years ago, using high-doses and often employing in vivo testing. Several disadvantages are encountered conducting or extrapolating data from animal studies due to differences in metabolism or exposure. The last decade saw considerable advancement in the development of in vitro tools and capabilities, and the challenges of the next decade will be integrating these platforms into applied product testing and acceptance by regulatory bodies. Governmental and validation agencies have launched and applied frameworks and "roadmaps" to support agile validation and acceptance of NAMs. Next-generation tobacco and nicotine products (NGPs) have the potential to offer reduced risks to smokers compared to cigarettes. These include heated tobacco products (HTPs) that heat but do not burn tobacco; vapor products also termed electronic nicotine delivery systems (ENDS), that heat an e-liquid to produce an inhalable aerosol; oral smokeless tobacco products (e.g., Swedish-style snus) and tobacco-free oral nicotine pouches. With the increased availability of NGPs and the requirement of scientific studies to support regulatory approval, NAMs approaches can supplement the assessment of NGPs. This review explores how NAMs can be applied to assess NGPs, highlighting key considerations, including the use of appropriate in vitro model systems, deploying screening approaches for hazard identification, and the importance of test article characterization. The importance and opportunity for fit-for-purpose testing and method standardization are discussed, highlighting the value of industry and cross-industry collaborations. Supporting the development of methods that are accepted by regulatory bodies could lead to the implementation of NAMs for tobacco and nicotine NGP testing.
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Affiliation(s)
- David Thorne
- BAT (Investments) Ltd., Southampton, Hampshire, United Kingdom
| | - Damian McHugh
- PMI R&D Philip Morris Products S. A., Neuchâtel, Switzerland
| | - Liam Simms
- Imperial Brands, Bristol, United Kingdom
| | - K. Monica Lee
- Altria Client Services LLC, Richmond, VA, United States
| | | | | | - Marianna Gaca
- BAT (Investments) Ltd., Southampton, Hampshire, United Kingdom
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5
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Cordery S, Thompson K, Stevenson M, Simms L, Chapman F, Grandolfo E, Malt L, Weaver S, Fearon IM, Nahde T. The Product Science of Electrically Heated Tobacco Products: An Updated Narrative Review of the Scientific Literature. Cureus 2024; 16:e61223. [PMID: 38939262 PMCID: PMC11209752 DOI: 10.7759/cureus.61223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/28/2024] [Indexed: 06/29/2024] Open
Abstract
Heated tobacco products represent a novel category of tobacco products in which a tobacco consumable is heated to a temperature that releases nicotine from the tobacco leaf but not to a temperature sufficient to cause combustion. Heated tobacco products may therefore have the potential to be a less harmful alternative for adult smokers who would otherwise continue to smoke cigarettes, as their use should result in exposure to substantially fewer and lower levels of toxicants. This update represents a two-year extension to our previous narrative review, which covered peer-reviewed journal articles published up to August 31, 2021. The scientific evidence published between 2021 and 2023 continues to indicate that aerosols produced from heated tobacco products contain fewer and substantially lower levels of harmful and potentially harmful constituents and that these observed reductions consistently translate to reduced biological effects in both in vitro and in vivo toxicological studies. Biomarker and clinical data from studies in which product use is controlled within a clinical setting continue to suggest changes in levels of biomarkers of exposure, biomarkers of potential harm, and clinical endpoints indicating the potential for reduced harm with switching to exclusive use of heated tobacco products in adult smokers. Overall, the available peer-reviewed scientific evidence continues to indicate that heated tobacco products offer promise as a potentially less harmful alternative to cigarettes, and as such, the conclusions of our original narrative review remain valid.
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Affiliation(s)
- Sarah Cordery
- Group Science and Regulatory Affairs, Imperial Brands Plc., Bristol, GBR
| | - Keith Thompson
- Independent Scientific Consultant, Elucid8 Holdings Ltd., Coleraine, GBR
| | - Matthew Stevenson
- Group Science and Regulatory Affairs, Imperial Brands Plc., Bristol, GBR
| | - Liam Simms
- Group Science and Regulatory Affairs, Imperial Brands Plc., Bristol, GBR
| | - Fiona Chapman
- Group Science and Regulatory Affairs, Imperial Brands Plc., Bristol, GBR
| | - Erika Grandolfo
- Group Science and Regulatory Affairs, Imperial Brands Plc., Bristol, GBR
| | - Layla Malt
- Group Science and Regulatory Affairs, Imperial Brands Plc., Bristol, GBR
| | - Sarah Weaver
- Group Science and Regulatory Affairs, Imperial Brands Plc., Bristol, GBR
| | - Ian M Fearon
- Scientific Research, whatIF? Consulting Ltd., Harwell, GBR
| | - Thomas Nahde
- Group Science and Regulatory Affairs, Imperial Brands Reemtsma, Hamburg, DEU
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6
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Keyser BM, Leverette R, McRae R, Wertman J, Shutsky T, Jordan K, Szeliga K, Makena P. In vitro toxicological evaluation of glo menthol and non-menthol heated tobacco products. Toxicology 2024; 504:153801. [PMID: 38614204 DOI: 10.1016/j.tox.2024.153801] [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: 03/26/2024] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 04/15/2024]
Abstract
Heated tobacco products (HTPs) are non-combustible, inhaled tobacco products that generate an aerosol with fewer and lower levels of toxicants, with a potential to reduce risk relative to cigarette smoking. Here, we assessed in vitro toxicological effects of three menthol (glo neo neoCLICK, neo Smooth Menthol and Fresh Menthol) and one non-menthol (neo Smooth Tobacco) variants of glo HTP, along with market comparators for cigarettes and HTPs. Limited chemical characterization of the study products revealed significantly lower levels of acetaldehyde, acrolein, crotanaldehyde and formaldehyde in test samples from HTPs than those from cigarettes. The glo HTPs were non-mutagenic in the bacterial reverse mutagenesis assay. Although, the whole aerosol exposures of glo HTPs were classified as genotoxic in the in vitro micronucleus assay, and cytotoxic in the NRU (monolayer) and MTT (3 dimensional EpiAirway™ tissues) assays, the cigarette comparators were the most toxic study products in each of these assessments. Further, glo HTPs elicited oxidative stress responses only at the highest dose tested, whereas the cigarette comparators were potent inducers of oxidative stress at substantially lower doses in the EpiAirway tissues. The comparator (non-glo) HTP results were similar to the glo HTPs in these assays. Thus, the glo HTPs exhibit substantially lower toxicity compared to cigarettes.
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Affiliation(s)
- Brian M Keyser
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA.
| | - Robert Leverette
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA
| | - Reagan McRae
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA
| | - John Wertman
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA
| | - Tom Shutsky
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA
| | - Kristen Jordan
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA
| | - Ken Szeliga
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA
| | - Patrudu Makena
- RAI Services Company; Scientific & Regulatory Affairs, 401 North Main Street, Winston-Salem, NC 27101, USA
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7
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Ohashi K, Hayashida A, Nozawa A, Ito S. RNA sequencing analysis of early-stage atherosclerosis in vascular-on-a-chip and its application for comparing combustible cigarettes with heated tobacco products. Curr Res Toxicol 2024; 6:100163. [PMID: 38571525 PMCID: PMC10987886 DOI: 10.1016/j.crtox.2024.100163] [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: 12/17/2023] [Revised: 02/27/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024] Open
Abstract
Our previous study showed promising results in replicating early-stage atherosclerosis when vascular endothelial cells (VECs) were exposed to cigarette smoke (CS) extract via M0 macrophages. We used an organ-on-a-chip system as an alternative to animal testing to model atherosclerosis, which is a complex disease involving endothelial and immune cell communications. By incorporating macrophages into the vascular-on-a-chip system, we aimed to mimic the indirect effects of inhalable substances, such as CS, on VECs. In the current study, we further examined the suitability of our in vitro system for mimicking early-stage atherosclerosis by transcriptomic analyses of VECs exposed to CS directly or indirectly via macrophages. We also incorporated M1 macrophages to replicate a preexisting inflammatory state. We found a greater number of differentially expressed genes (DEGs) in direct exposure methods than indirect exposure methods. However, a pathway analysis showed that the direct exposure of CS to VECs primarily caused cell death-related pathway alterations, and the "Atherosclerosis Signaling" pathway was predicted to be negatively regulated. Indirect exposure via M0 macrophages similarly showed that the identified DEGs were related to cell death, while the "Atherosclerosis Signaling" pathway was predicted to be activated. In contrast, cell death-related pathway alterations were not observed by indirect exposure of CS to VECs via M1 macrophages, but the pathway perturbations were similar to a pro-inflammatory positive control. In addition, the "Atherosclerosis Signaling" pathway was predicted to be activated in VECs that were indirectly exposed to CS via M1 macrophages. These results suggest that M0 or M1 macrophages contribute to atherogenic transcriptomic changes in VECs, although they affect cell death-related pathways differently. We also used indirect exposure methods to compare the effects of CS and heated tobacco product (HTP) aerosol. Notably, gene expression changes related to atherosclerosis were less pronounced in HTP aerosol-exposed VECs than CS. Our study highlights the utility of the vascular-on-a-chip system with indirect exposure of CS extract via macrophages for replicating atherogenesis and suggests a reduced risk potential of the HTP. This research contributes to advancing alternatives to animal testing for toxicological and disease modeling studies.
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Affiliation(s)
| | | | - Atsuko Nozawa
- Scientific Product Assessment Center, Japan Tobacco Inc., 6-2, Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan
| | - Shigeaki Ito
- Scientific Product Assessment Center, Japan Tobacco Inc., 6-2, Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan
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8
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Mori A, Ito S, Sekine T. A revision of the multiple-path particle dosimetry model focusing on tobacco product aerosol dynamics. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3796. [PMID: 38185887 DOI: 10.1002/cnm.3796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/15/2023] [Accepted: 11/26/2023] [Indexed: 01/09/2024]
Abstract
To assess the health impact of inhaled aerosols, it is necessary to understand aerosol dynamics and the associated dosimetry in the human respiratory tract. Although several studies have measured or simulated the dosimetry of aerosol constituents, the respiratory tract focus areas have been limited. In particular, the aerosols generated from tobacco products are complex composites and simulating their dynamics in the respiratory tract is challenging. To assess the dosimetry of the aerosol constituents of tobacco products, we developed a revised version of the Multiple-Path Particle Dosimetry (MPPD) model, which employs (1) new geometry based on CT-scanned human respiratory tract data, (2) convective mixing in the oral cavity and deep lung, and (3) constituent partitioning between the tissue and air, and clearance. The sensitivity analysis was conducted using aerosols composed of four major constituents of electronic cigarette (EC) aerosols to investigate the parameters that have a significant impact on the results. In addition, the revised model was run with 4 and 10 constituents in ECs and conventional cigarettes (CCs), respectively. Sensitivity analysis revealed that the new modeling and the physicochemical properties of constituents had a considerable impact on the simulated aerosol concentration and dosimetry. The simulations could be carried out within 3 min even when 10 constituents of CC aerosols were analyzed simultaneously. The revised model based on MPPD is an efficient and easy-to-use tool for understanding the aerosol dynamics of CC and EC constituents and their effect on the human body.
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Affiliation(s)
- Akina Mori
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., Yokohama, Japan
| | - Shigeaki Ito
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., Yokohama, Japan
| | - Takashi Sekine
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., Yokohama, Japan
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9
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Horinouchi T, Mazaki Y, Miwa S. Mechanism of cytotoxicity induced by the cigarette smoke extract (CSE) of heated tobacco products in vascular smooth muscle cells: A comparative study of the cytotoxic effects of CSE and the ferroptosis inducer, erastin. J Pharmacol Sci 2024; 154:86-96. [PMID: 38246732 DOI: 10.1016/j.jphs.2023.12.010] [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: 10/17/2023] [Revised: 12/08/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024] Open
Abstract
Heated tobacco products (HTPs) are marketed worldwide as less harmful alternatives to combustible cigarettes; however, their cytotoxic mechanisms in vascular smooth muscle cells are poorly understood. Ferroptosis is defined as iron-dependent cell death caused by the accumulation of lipid peroxidation products. In this study, the cytotoxic effects of nicotine- and tar-free cigarette smoke extracts (CSE) derived from three types of HTPs and the ferroptosis inducer, erastin, on vascular smooth muscle A7r5 cells were compared. Cigarette smoke from all HTPs was generated according to the following puffing regime: 55 mL, puff volume; 30 s, puff interval; 2 s, puff duration; bell-shaped, puff profile; and no blocking of the ventilation holes. Erastin and CSE decreased mitochondrial metabolic activity and increased lactate dehydrogenase leakage. The cytotoxic effects of erastin were almost completely inhibited by the radical-trapping antioxidant, UAMC-3203; iron chelator, deferoxamine mesylate (DFO); 12/15-lipoxygenase (12/15-LOX) inhibitor, baicalein; and selective 15-LOX inhibitor, ML351. In contrast, CSE-induced cell damage was partially attenuated by UAMC-3203, baicalein, and ML351 but not by DFO. These results suggest that erastin induces ferroptosis via 15-LOX-mediated iron-dependent lipid peroxidation, whereas CSE causes iron-independent cell damage via 15-LOX-mediated lipid peroxidation-dependent and -independent mechanisms.
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Affiliation(s)
- Takahiro Horinouchi
- Department of Cellular Pharmacology, Graduate School of Medicine, Hokkaido University, North 15, West 7, Kita-ku, Sapporo, 060-8638, Japan.
| | - Yuichi Mazaki
- Department of Cellular Pharmacology, Graduate School of Medicine, Hokkaido University, North 15, West 7, Kita-ku, Sapporo, 060-8638, Japan
| | - Soichi Miwa
- Toyooka General Hospital, 1094 Tobera, Toyooka, Hyogo, 668-8501, Japan
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10
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Nishihara D, Yuki D, Suzuki T, Sakaguchi C, Nagata Y, Kakehi A. A Randomized Control Study in Healthy Adult Smokers to Assess Reduced Exposure to Selected Cigarette Smoke Constituents in Switching to the Novel Heated Tobacco Product DT3.0a. Clin Pharmacol Drug Dev 2024; 13:45-57. [PMID: 37680118 DOI: 10.1002/cpdd.1322] [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: 05/15/2023] [Accepted: 08/06/2023] [Indexed: 09/09/2023]
Abstract
This was a randomized, controlled, open-label, confinement study to assess change in exposure to selected cigarette smoke constituents in healthy adult cigarette smokers who switched to using a novel heated tobacco product (direct heating tobacco system, platform 3, generation 3, version a [DT3.0a]). Sixty nonmenthol cigarette smokers were randomized into 1 of the 4 study groups in which subjects switched to a nonmenthol type of tobacco stick used with DT3.0a, switched to a nonmenthol tobacco stick used with an in-market heated tobacco product device (THS), continued to smoke nonmenthol cigarettes, or stopped smoking. Furthermore, 30 menthol cigarette smokers were randomized into 1 of the 2 study groups in which subjects switched to a menthol tobacco stick used with DT3.0a (mDT3.0a) or continued to smoke menthol cigarettes. Fifteen biomarkers of exposure to selected harmful and potentially harmful constituents (HPHCs) were measured during the 5-day exposure period, followed by assessment of nicotine pharmacokinetics with the assigned product. Results indicated that switching to DT3.0a, THS, and mDT3.0a showed significant exposure reductions in most of the selected HPHCs as compared to continuing smoking cigarettes, with reductions being similar in magnitude to reductions observed with smoking cessation. For DT3.0a and mDT3.0a, nicotine pharmacokinetic parameters were not remarkably different from those obtained for cigarettes and the THS except that a longer time to maximum concentration was obtained following use of the mDT3.0a. In conclusion, switching from smoking cigarettes to DT3.0a or THS use reduced exposure to most of the selected HPHCs, and no remarkable differences were observed for the measurements obtained from different flavors of DT3.0a stick.
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Affiliation(s)
- Daisuke Nishihara
- Scientific and Regulatory Affairs, Japan Tobacco Inc., Minato-Ku, Tokyo, Japan
| | - Dai Yuki
- Scientific and Regulatory Affairs, Japan Tobacco Inc., Minato-Ku, Tokyo, Japan
| | - Takuya Suzuki
- Scientific and Regulatory Affairs, Japan Tobacco Inc., Minato-Ku, Tokyo, Japan
| | - Chikako Sakaguchi
- Scientific and Regulatory Affairs, Japan Tobacco Inc., Minato-Ku, Tokyo, Japan
| | - Yasufumi Nagata
- Scientific and Regulatory Affairs, Japan Tobacco Inc., Minato-Ku, Tokyo, Japan
| | - Aoi Kakehi
- Scientific and Regulatory Affairs, Japan Tobacco Inc., Minato-Ku, Tokyo, Japan
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11
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Ohashi K, Hayashida A, Nozawa A, Matsumura K, Ito S. Human vasculature-on-a-chip with macrophage-mediated endothelial activation: The biological effect of aerosol from heated tobacco products on monocyte adhesion. Toxicol In Vitro 2023; 89:105582. [PMID: 36933580 DOI: 10.1016/j.tiv.2023.105582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/28/2023] [Accepted: 03/13/2023] [Indexed: 03/18/2023]
Abstract
Heated tobacco products (HTPs) are expected to have the potential to reduce risks of smoking-associated cardiovascular disease (CVD). However, mechanism-based investigations of the effect of HTPs on atherosclerosis remain insufficient and further studies under human-relevant situations are desired for deeper understanding of the reduced risk potential of HTPs. In this study, we first developed an in vitro model of monocyte adhesion by considering macrophage-derived proinflammatory cytokine-mediated endothelial activation using an organ-on-a-chip (OoC), which provided great opportunities to mimic major aspects of human physiology. Then biological activities of aerosol from three different types of HTPs in terms of monocyte adhesion were compared with that of cigarette smoke (CS). Our model showed that the effective concentration ranges of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were close to the actual condition in CVD pathogenesis. The model also showed that monocyte adhesion was less induced by each HTP aerosol than CS, which may be caused by less proinflammatory cytokine secretion. In summary, our vasculature-on-a-chip model assessed the difference in biological effects between cigarettes and HTPs, and suggested a reduced risk potential of HTPs for atherosclerosis.
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Affiliation(s)
- Kazuhiro Ohashi
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama 227-8512, Kanagawa, Japan.
| | - Ayaka Hayashida
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama 227-8512, Kanagawa, Japan.
| | - Atsuko Nozawa
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama 227-8512, Kanagawa, Japan.
| | - Kazushi Matsumura
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama 227-8512, Kanagawa, Japan.
| | - Shigeaki Ito
- Scientific Product Assessment Center, R&D Group, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama 227-8512, Kanagawa, Japan.
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