Acute exposure to waterpipe tobacco smoke induces changes in the oxidative and inflammatory markers in mouse lung

Pulmonary effects of waterpipe generated smoke in adult diabetic rats

Waterpipe smoking (WPS) is associated with pulmonary inflammation and DNA damage. Tobacco use among diabetic patients adds substantial clinical and public health burden. This study aims to investigate the combined pulmonary effects of diabetes and smoking. To achieve this goal, type 1 diabetes (T1D) was induced in adult male rats by Streptozotocin (65 mg/kg) injection. Rats were then exposed either to fresh air or WPS for one hour daily over five weeks (five days/week). Lung remodeling was evaluated by histology. Changes affecting inflammation, oxidative stress, apoptosis and survival pathways were characterized by real-time quantitative PCR and Western blot. Our findings showed that T1D was associated with pulmonary remodeling characterized by increases in lung weight/BW ratio, exacerbated by WPS, and elevated alveolar count. Both T1D and WPS exposure led to an accumulation of alveolar foamy macrophages and decreased alveolar septal thickness. Upregulation in the transcript levels of pro-inflammatory cytokine, TNF-α and anti-inflammatory marker, IL-10, were reported in diabetic lungs irrespective of WPS exposure. Moreover, diabetic lungs also displayed significant changes in the expression of mitochondrial complexes III and IV and antioxidant enzyme, SOD2, irrespective of the exposure condition. We also noted significant downregulation in the expression of caspases 3 and 9, p-P53/P53 ratio and JNK protein in diabetic lungs compared to control irrespective of the exposure condition. Lastly, diabetes and WPS exposure triggered significant decreases in EGFR expression. In conclusion, we show for the first time pulmonary remodeling and damages caused by the combined effects of T1D and smoking. Our findings highlight the pressing need for future better management of waterpipe consumption among patients with diabetes.

Use of Hookah and Age of Asthma Onset Among US Adults

Objective

To explore the association of hookah use on the age of asthma onset among adults who were asthma/COPD free and who did not use cigarettes, cigars, electronic cigarettes or smokeless tobacco prior to asthma onset.

Methods

Secondary data analyses were conducted of the waves 1-6 (2013-2021) of the US nationally representative Population Assessment of Tobacco and Health Study among adults (>18 years). The four hookahs use exposures evaluated were (1) past 30-day (P30D) hookah use at the first wave of participation, (2) total number of waves before asthma onset in which adults reported P30D hookah use, (3) total number of years since first hookah use, and (4) average length of hookah sessions. Lower and upper age limits were estimated using the age reported at the first wave of participation and the number of weeks between follow-up waves until asthma was first reported or censored. Associations of the exposures on the age of asthma onset were estimated using weighted interval-censoring-Cox-regression.

Results

The total sample size for analysis was 5,768, representing 66.6 million adults. There was a lack of statistical power to detect differences in the age of asthma onset by (1) P30D hookah use (Adjusted Hazard Ratio (AHR) 3.77, 95CI%: .90-15.71). There was an association between (2) total number of waves of P30D hookah use (AHR 1.72, 95% CI 1.28-2.30), (3) total number of years since first hookah use (AHR 2.94, 95% CI 1.36-6.36), and (4) average length of hookah sessions (AHR 4.52, 95% CI 1.61-12.67) with the age of asthma onset. Females and Hispanics with over one year since first hookah use had higher risk of earlier age of asthma onset.

Conclusion

Prevention and cessation programs for adults who use hookah are needed to educate the public, protect public health, prevent adverse health outcomes, and motivate hookah users to stop.

The inflammation and oxidative status of rat lung tissue following smoke/vapor exposure via E-cigarette, cigarette, and waterpipe

BACKGROUND

Tobacco smoking is a major worldwide health issue that contributes to millions of deaths annually. Electronic cigarettes (E-cigarettes) are also harmful. Smoke/vapor from E-cigarettes and tobacco products consists of free radicals and other toxic substances. Tissue damage in smokers, such as lungs, is highly observed and is linked to oxidative damage and inflammation.

METHODS

The inflammation and oxidative status of rat lung tissues was examined following whole-body smoke/vapor exposure via E-cigarette, cigarette, and waterpipe for 2 h daily, 5 days per week for 8 weeks.

RESULTS

Lung tissue damage was higher in cigarettes and waterpipe groups compared to the E-cigarette group. Collectively, there was a significant increase (p < 0.05) in the mRNA expression of pro-inflammatory mediators (TNF-α, NF-κB, IL-1β) with the exception of IL-1β in the E-cigarettes group. As for the anti-inflammatory mediators (Nrf2 and IL-10), a significant reduction (p < 0.05) of mRNA expression was observed with the exception of Nrf2 in the E-cigarette group. As for IL-6, there was a significant increase in its mRNA expression (p < 0.05) in the cigarette and waterpipe groups. There was also a significant decrease (p < 0.05) in the antioxidant activity of all antioxidants tested (GPx, SOD, and CAT) in all groups with the exception of SOD in the cigarette group.

CONCLUSION

Smoke/vapor administered via E-cigarette, cigarette, and waterpipe elicits inflammation and oxidative stress in rat lungs that is accompanied by histopathological changes.

Chronic Exposure to Two Regimens of Waterpipe Smoke Elicits Lung Injury, Genotoxicity, and Mitochondrial Impairment with the Involvement of MAPKs Activation in Mice

While the pulmonary effects of regular waterpipe smoking (R-WPS) are well-defined, the impact of occasional waterpipe smoking (O-WPS) on the lungs remains less established. This study investigated the pulmonary toxicity and underlying mechanisms of O-WPS versus R-WPS following 6 months of exposure, focusing on histopathology, inflammation in the lung, bronchoalveolar lavage fluid (BALF), and plasma, as well as oxidative stress, genotoxicity, mitochondrial dysfunction, and the expression of mitogen-activated protein kinases (MAPKs) in lung homogenates. Exposure to both O-WPS and R-WPS resulted in significant histological changes, including increased numbers of alveolar macrophages and lymphocytes, as well as interstitial fibrosis. Only R-WPS increased the number of neutrophil polymorphs and plasma cells. R-WPS also significantly increased the chemokines CXCL1, CXCL2, and CCL2 in the lung, BALF, and plasma, while O-WPS increased CXCL1 and CXCL2 in the lung and CXCL1 in the plasma. Both exposure regimens significantly increased lung injury markers, including matrix metalloproteinase-9 and myeloperoxidase. Additionally, R-WPS induced a significant increase in the cytokines IL1β, IL6, and TNFα in the lung, BALF, and plasma, while O-WPS elevated IL1β and IL6 in the lung. Oxidative stress was observed, with increased levels of thiobarbituric acid reactive substances and superoxide dismutase in both the O-WPS and R-WPS groups. Exposure to either O-WPS or R-WPS triggered genotoxicity and altered mitochondrial complex activities. R-WPS exposure also resulted in elevated expression of p-JNK/JNK, p-ERK/ERK, and p-p38/p38, while O-WPS augmented the p-ERK/ERK ratio in the lungs. Taken together, these findings indicate that both O-WPS and R-WPS contribute to lung injury and induce inflammation, oxidative stress, genotoxicity, and mitochondrial dysfunction, with R-WPS having a more pronounced effect. These effects were associated with the activation of MAPKs.

Toxicity of waterpipe tobacco smoking: the role of flavors, sweeteners, humectants, and charcoal

Waterpipe tobacco (WPT) smoking is a public health concern, particularly among youth and young adults. The global spread of WPT use has surged because the introduction of pre-packaged flavored and sweetened WPT, which is widely marketed as a safer tobacco alternative. Besides flavorants and sugars, WPT additives include humectants, which enhance the moisture and sweetness of WPT, act as solvents for flavors, and impart smoothness to the smoke, thus increasing appeal to users. In the United States, unlike cigarette tobacco flavoring (with the exception of menthol), there is no FDA product standard or policy in place prohibiting sales of flavored WPT. Research has shown that the numerous fruit, candy, and alcohol flavors added to WPT entice individuals to experience those flavors, putting them at an increased risk of exposure to WPT smoke-related toxicants. Additionally, burning charcoal briquettes-used as a heating source for WPT-contributes to the harmful health effects of WPT smoking. This review presents existing evidence on the potential toxicity resulting from humectants, sugars, and flavorants in WPT, and from the charcoal used to heat WPT. The review discusses relevant studies of inhalation toxicity in animal models and of biomarkers of exposure in humans. Current evidence suggests that more data are needed on toxicant emissions in WPT smoke to inform effective tobacco regulation to mitigate the adverse impact of WPT use on human health.

Salivary oxidative stress biomarkers in periodontitis-free smokers: a cross sectional study

BACKGROUND

Salivary oxidative stress has been extensively studied with attempts to correlate changes in the oxidative stress markers with local and systemic factors, including smoking. The objective of this study was to evaluate the influence of two forms of smoking, cigarettes and waterpipe smoking (WPS), on selected oxidative stress biomarkers in saliva.

METHODS

Three groups of participants were enrolled into the study, controls (never smokers), cigarette smokers and WPS. Participants were clinically free from periodontitis and systemic conditions known to affect the saliva constituents. Unstimulated whole saliva samples were collected according to a standard protocol and concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG), myeloperoxidase (MPO), malondialdehyde (MDA), total antioxidant capacity (TAC), and cortisol. The one-way ANOVA test was used to compare the levels of each oxidative stress biomarker between the three study groups and the hierarchical linear regression analysis was used to test the levels of salivary cortisol for prediction of other oxidative stress biomarkers. Significance levels were set at 95% confidence intervals and probability values ≤0.05.

RESULTS

8-OHdG was highest in WPS group (mean±SE 11,030.35±1829.16 pg/mL) while MDA and cortisol levels were highest in the cigarette smokers group (mean±SE 3.33±0.52 µM and 3.99±0.48 ng/mL, respectively) and MPO was highest in the control group (mean±SE 7.760±1.55 ng/mL). WPS group showed the highest TAC (mean±SE 0.3±0.03 mM). However, none of the tested makers reached a statistically significant difference.

CONCLUSIONS

Despite subtle changes in some biomarkers, the salivary oxidative stress does not appear to be significantly influenced by smoking habits in periodontitis-free smokers.

Water-pipe Tobacco Components and their Association with Oxidative Stress

Oxidative stress (OS) results from an imbalance between the formation and detoxification of reactive species. Although reactive species at low or moderate levels play numerous physiological roles, high concentrations can lead to disturbances in signaling and metabolic pathways and cause different metabolic, chronic, and age-related disorders. Several endogenous and exogenous processes may lead to the formation of reactive species. The severity of OS can be reduced with the help of antioxidants. Tobacco is one of the most important environmental factors contributing to reactive species production. After cigarette smoking, water-pipe tobacco (WPT) smoking is ranked as the second most popular tobacco product. Its popularity is proliferating due to flavored products, social acceptability, etc. However, studies have shown that WPT smoking is associated with an increased risk of arterial stiffness, ischemic heart disease, and several cancer types. In this study, we aimed to review the most recent evidence on WPT smoking constituents and their association with OS.

Exposure to Electronic Waterpipes Increases the Risk of Occlusive Cardiovascular Disease in C57BL/6J Mice

INTRODUCTION

It is well documented that cardiovascular disease (CVD) is the leading cause of death in the US and worldwide, with smoking being the most preventable cause. Additionally, most smokers die from thrombotic-based diseases, in which platelets play a major role. To this end, because of the proven harm of smoking, several novel tobacco products such as electronic(e)-waterpipe have been gaining popularity among different sectors of the population, partly due to their "false" safety claims. While many investigators have focused on the negative health effects of traditional cigarettes and e-cigarettes on the cardiovascular system, virtually little or nothing is known about e-waterpipes, which we investigated herein.

METHODS AND MATERIALS

To investigate their occlusive CVD effects, we employed a whole-body mouse exposure model of e-waterpipe vape/smoke and exposed C57BL/6J male mice (starting at 7 weeks of age) for 1 month, with the controls exposed to clean air. Exposures took place seven times a week, according to the well-known Beirut protocol, which has been employed in many studies, as it mimics real-life waterpipe exposure scenarios; specifically, 171 puffs of 530 ml volume of the e-liquid at 2.6 s puff duration and 17 s puff interval.

RESULTS

The e-waterpipe exposed mice had shortened bleeding and occlusion times, when compared to the clean air controls, indicating a prothrombotic phenotype. As for the mechanism underlying this phenotype, we found that e-waterpipe exposed platelets exhibited enhanced agonist-triggered aggregation and dense granule secretion. Also, flow cytometry analysis of surface markers of platelet activation showed that both P-selectin and integrin GPIIb-IIIa activation were enhanced in the e-waterpipe exposed platelets, relative to the controls. Finally, platelet spreading and Akt phosphorylation were also more pronounced in the exposed mice.

CONCLUSION

We document that e-waterpipe exposure does exert untoward effects in the context of thrombosis-based CVD, in part, via promoting platelet hyperreactivity.

Waterpipe smoke inhalation induces lung injury and aortic endothelial dysfunction in mice

Waterpipe tobacco smoking (WPS) inhalation has been shown to trigger endothelial dysfunction and atherosclerosis. However, the mechanisms underlying these effects are still unknown. Here, we assessed the impact and underlying mechanism of WPS exposure for one month on endothelial dysfunction using aortic tissue of mice. The duration of the session was 30 min/day and 5 days/week. Control mice were exposed to air. Inhalation of WPS induced an increase in the number of macrophages and neutrophils and the concentrations of protein, tumor necrosis factor alpha (TNF alpha), interleukin (IL)-1beta, and glutathione in bronchoalveolar lavage fluid. Moreover, the concentrations of proinflammatory cytokines (TNF alpha, IL-6 and IL-1beta), adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin and P-selectin) and markers of oxidative stress (lipid peroxidation, glutathione, superoxide dismutase and nitric oxide) in aortic homogenates of mice exposed to WPS were significantly augmented compared with air exposed mice. Likewise, the concentration of galectin-3 was significantly increased in the aortic homogenates of mice exposed to WPS compared with control group. WPS inhalation induced vascular DNA damage assessed by comet assay and apoptosis characterized by a significant increase in cleaved caspase-3. While the aortic expression of phosphorylated nuclear factor kappaB (NF-kappaB) was significantly increased following WPS inhalation, the concentration of sirtuin 1 (SIRT1) was significantly decreased in WPS group compared with air-exposed group. In conclusion, our study provided evidence that WPS inhalation triggers lung injury and endothelial inflammation, oxidative stress and apoptosis which were associated with nuclear factor-kappaB activation and SIRT1 down-regulation.

Predicting thrombotic cardiovascular outcomes induced by waterpipe-associated chemicals using comparative toxicogenomic database: Genes, phenotypes, and pathways

Hookah, or waterpipe, is a tobacco smoking device that has gained popularity in the United States. A growing body of evidence demonstrates that waterpipe smoke (WPS) is associated with various adverse effects on human health, including infectious diseases, cancer, and cardiovascular diseases (CVDs), particularly thrombotic events. However, the molecular mechanisms through which WPS contributes to disease development remain unclear. In this study, we utilized an analytical approach based on the Comparative Toxicogenomics Database (CTD) to integrate chemical, gene, phenotype, and disease data to predict potential molecular mechanisms underlying the effects of WPS, based on its chemical and toxicant profile. Our analysis revealed that CVDs were among the top disease categories with regard to the number of curated interactions with WPS chemicals. We identified 5674 genes common between those modulated by WPS chemicals and traditional tobacco smoking. The CVDs with the most curated interactions with WPS chemicals were hypertension, atherosclerosis, and myocardial infarction, whereas "particulate matter", "heavy metals", and "nicotine" showed the highest number of curated interactions with CVDs. Our analysis predicted that the potential mechanisms underlying WPS-induced thrombotic diseases involve common phenotypes, such as inflammation, apoptosis, and cell proliferation, which are shared across all thrombotic diseases and the three aforementioned chemicals. In terms of enriched signaling pathways, we identified several, including chemokine and MAPK signaling, with particulate matter exhibiting the most statistically significant association with all 12 significant signaling pathways related to WPS chemicals. Collectively, our predictive comprehensive analysis provides evidence that WPS negatively impacts health and offers insights into the potential mechanisms through which it exerts these effects. This information should guide further research to explore and better understand the WPS and other tobacco product-related health consequences.

Waterpipe smoke inhalation potentiates cardiac oxidative stress, inflammation, mitochondrial dysfunction, apoptosis and autophagy in experimental hypertension

Cigarette smoking worsens the health of hypertensive patients. However, less is known about the actions and underlying mechanisms of waterpipe smoke (WPS) in hypertension. Therefore, we evaluated the effects of WPS inhalation in mice made hypertensive (HT) by infusing angiotensin II for six weeks. On day 14 of the infusion of angiotensin II or vehicle (normotensive; NT), mice were exposed either to air or WPS for four consecutive weeks. Each session was 30 min/day and 5 days/week. In NT mice, WPS increased systolic blood pressure (SBP) compared with NT air-exposed group. SBP increase was elevated in HT+WPS group versus either HT+air or NT+WPS. Similarly, the plasma levels of brain natriuretic peptide, C-reactive protein, 8-isoprostane and superoxide dismutase were increased in HT+WPS compared with either HT+air or NT+WPS. In the heart tissue, several markers of oxidative stress and inflammation were increased in HT+WPS group vs the controls. Furthermore, mitochondrial dysfunction in HT+WPS group was more affected than in the HT+air or HT+WPS groups. WPS inhalation in HT mice significantly increased cardiac DNA damage, cleaved caspase 3, expression of the autophagy proteins beclin 1 and microtubule-associated protein light chain 3B, and phosphorylated nuclear factor κ B, compared with the controls. Compared with HT+air mice, heart histology of WPS-exposed HT mice showed increased cardiomyocyte damage, neutrophilic and lymphocytic infiltration and focal fibrosis. We conclude that, in HT mice, WPS inhalation worsened hypertension, cardiac oxidative stress, inflammation, mitochondrial dysfunction, DNA damage, apoptosis and autophagy. The latter effects were associated with a mechanism involving NF-κB activation.

The Protective Effects of the Combination of Vitamin E and Swimming Exercise on Memory Impairment Induced by Exposure to Waterpipe Smoke

BACKGROUND

Waterpipe smoking (WP) exposure involves a negative health impact, including memory deficit, which is attributed to the elevation of oxidative stress. Vitamin E (VitE) in combination with swimming exercise exerts protective effects that prevent memory impairment. In the current study, the modulation of WP-induced memory impairment by the combined effect of VitE and swimming exercise (SE) was investigated.

METHODS

Animals were exposed to WP one hour/day, five days per week for four weeks. Simultaneously, VitE (100 mg/kg, six days/week for four weeks) was administered via oral gavage, and the rats were made to swim one hour/day, five days/week for four weeks. Changes in memory were evaluated using radial arm water maze (RAWM), and oxidative stress biomarkers were examined in the hippocampus.

RESULTS

WP exposure induced short-term/long-term memory impairment (p<0.05). This impairment was prevented by a combination of VitE with SE (p<0.05). Additionally, this combination normalized the hippocampal catalase, GPx, and GSH/GSSG ratios that were modulated by WP (p<0.05). The combination further reduced TBARs levels below those of the control group (p<0.05).

CONCLUSION

WP-induced memory impairments were prevented by the combination of VitE with SE. This could be attributed to preserving the hippocampal oxidative mechanism by combining VitE and SE during WP exposure.

Increased airway resistance among exclusive waterpipe smokers detected using impulse oscillometry

INTRODUCTION

Waterpipe smoking is increasing in popularity, yet the evidence implicating waterpipe smoking in lung disease is limited. We hypothesized that impulse oscillometry (IOS) would detect airway abnormalities in waterpipe smokers (WPS).

METHODS

We studied 210 participants, 40 years or older, from the community, of whom 92 were exclusive WPS and 118 were never-smokers. Waterpipe smoking history was assessed using a validated questionnaire. All participants underwent spirometry, and IOS and absolute and percentage predicted results (for age, sex, height, and weight) were compared between WPS and nonsmokers. The association of IOS parameters with waterpipe smoking duration and extent (waterpipe smoked/day * smoking duration) was evaluated using linear regression.

RESULTS

WPS smoked on average 1.8 ± 1.2 waterpipes/day, over an average duration of 23.3 ± 39.8 years. WPS and nonsmokers were largely asymptomatic and had similar age, body mass index, sex distribution, and spirometric values. Nevertheless, WPS had higher IOS measured resistance at 5Hz compared to nonsmokers, (0.53 ± 0.2 vs. 0.48 ± 0.2 kPa/L/s, P = 0.03) and higher percentage-predicted resistance (124.5 ± 36.3 vs. 115.7% ± 35.6%, P = 0.04). Waterpipe smoking duration was also associated with resistance (β = 0.04 kPa/L/s/year, P = 0.01) and with percentage-predicted resistance (β = 0.05/year, P = 0.02). Waterpipe smoking extent was associated with resistance (β = 0.009 kPa/L/s/waterpipe-year, P = 0.04), while the association with percentage-predicted resistance was near significance (β = 0.009/waterpipe-year, P = 0.07).

CONCLUSIONS

Waterpipe smoking is associated with increased airway resistance assessed by IOS but not by spirometry in largely asymptomatic individuals from the community.

Acute Outcomes of Cigarette Smoke and Electronic Cigarette Aerosol Inhalation in a Murine Model

Cigarette smoking throughout life causes serious health issues in the lungs. The electronic cigarette (E-Cig) use increased, since it was first introduced in the world. This research work compared the short-term exposure consequences to e-cigarette vapor and cigarette smoke in male mice. Forty-five C57BL/6 mice were randomized into control (C) in an ambient air exposition cigarette smoke (CS) and aerosol electronic cigarette (EC), both were exposed to 120 puffs, 3 times/day during five days. Then, in the experimental protocol, the euthanized mice had their tissues removed for analysis. Our study showed that CS and EC resulted in higher cell influx into the airways, and an increase in macrophage counts in CS (209.25 ± 7.41) and EC (220.32 ± 8.15) when compared to C (108.40 ± 4.49) (p < 0.0001). The CS (1.92 ± 0.23) displayed a higher pulmonary lipid peroxidation as opposed to C (0.93 ± 0.06) and EC (1.23 ± 0.17) (p < 0.05). The EC (282.30 ± 25.68) and CS (368.50 ± 38.05) promoted increased levels of interleukin 17 when compared to C (177.20 ± 10.49) (p < 0.05). The EC developed shifts in lung histoarchitecture, characterized by a higher volume density in the alveolar air space (60.21; 55.00-65.83) related to C (51.25; 18.75-68.75) and CS (50.26; 43.75-62.08) (p =0.002). The EC (185.6 ± 9.01) presented a higher respiratory rate related to CS (133.6 ± 10.2) (p < 0.002). Therefore, our findings demonstrated that the short-term exposure to e-cig promoted more acute inflammation comparing to cigarette smoke in the ventilatory parameters of the animals.

Genomic Analysis of Waterpipe Smoke-Induced Lung Tumor Autophagy and Plasticity

The role of autophagy in lung cancer cells exposed to waterpipe smoke (WPS) is not known. Because of the important role of autophagy in tumor resistance and progression, we investigated its relationship with WP smoking. We first showed that WPS activated autophagy, as reflected by LC3 processing, in lung cancer cell lines. The autophagy response in smokers with lung adenocarcinoma, as compared to non-smokers with lung adenocarcinoma, was investigated further using the TCGA lung adenocarcinoma bulk RNA-seq dataset with the available patient metadata on smoking status. The results, based on a machine learning classification model using Random Forest, indicate that smokers have an increase in autophagy-activating genes. Comparative analysis of lung adenocarcinoma molecular signatures in affected patients with a long-term active exposure to smoke compared to non-smoker patients indicates a higher tumor mutational burden, a higher CD8+ T-cell level and a lower dysfunction level in smokers. While the expression of the checkpoint genes tested-PD-1, PD-L1, PD-L2 and CTLA-4-remains unchanged between smokers and non-smokers, B7-1, B7-2, IDO1 and CD200R1 were found to be higher in non-smokers than smokers. Because multiple factors in the tumor microenvironment dictate the success of immunotherapy, in addition to the expression of immune checkpoint genes, our analysis explains why patients who are smokers with lung adenocarcinoma respond better to immunotherapy, even though there are no relative differences in immune checkpoint genes in the two groups. Therefore, targeting autophagy in lung adenocarcinoma patients, in combination with checkpoint inhibitor-targeted therapies or chemotherapy, should be considered in smoker patients with lung adenocarcinoma.

Waterpipe smoke-induced hypercoagulability and cardiac injury in mice: Influence of cessation of exposure

Waterpipe tobacco smoking has gained worldwide popularity, particularly among youths. Several clinical and experimental studies have reported that waterpipe smoking (WPS) injures the cardiovascular system. However, the impact of smoking cessation (CS) on the cardiovascular toxicity induced by WPS received scant attention. Hence, we assessed, in C57BL/6 mice, the cardiovascular effects of WPS exposure for 3 months followed by 3 months of SC, as compared with mice exposed for either 3 months to WPS or air (control). WPS exposure induced hypertension, prothrombotic events both in vivo and in vitro and increased the plasma concentrations of tissue factor, fibrinogen and plasminogen activator inhibitor-1. These effects were significantly alleviated by SC. In heart tissue, the levels of troponin I, creatine kinase, lipid peroxidation, 8-isoprostane, tumor necrosis factor α, inteleukin 6, DNA damage and cleaved caspase-3 were significantly increased by WPS exposure. These actions were significantly reduced in the group of mice exposed to WPS followed by SC. Similarly, the increase in the level of nuclear factor κ-β induced by WPS exposure was significantly mitigated by SC. Immunohistochemical analysis of the hearts showed that WPS exposure increased the expression of nuclear factor erythroid-derived 2-like 2 by cardiomyocytes. The latter effect was significantly reduced by SC. Taken together, our data show that SC is associated with amelioration of WPS induced hypertension, prothrombotic events and cardiac oxidative stress, inflammation, DNA damage and apoptosis.

Waterpipe smoking: a review of pulmonary and health effects

Waterpipe smoking is an old form of tobacco smoking, originating in Persia and the Middle East. The popularity of the waterpipe is increasing worldwide, particularly among young adults, and there are widespread misconceptions regarding its negative health effects. The inhaled smoke of the waterpipe contain several toxic and hazardous materials including nicotine, tar, polyaromatic hydrocarbons and heavy metals, all of which are proven to be related to lung diseases and cancer. Regular waterpipe smoking is associated with respiratory symptoms, a decrease in pulmonary function and increased risk for lung disease such as COPD. Additional negative health effects include increased risk for arterial stiffness, ischaemic heart disease and several cancer types including lung cancer. This review summarises the negative health effects of waterpipe smoking, with emphasis on cardiorespiratory complications. Increased awareness and knowledge amongst healthcare professionals will hopefully help identify waterpipe smokers and promote patient education. Applying World Health Organization (WHO) regulations will provide a synergistic effect in reducing waterpipe use and associated disease.

Ameliorative effects of curcumin and caffeic acid against short term exposure of waterpipe tobacco smoking on lung, heart and kidney in mice

This study aims to evaluate the chemopreventive activity of two antioxidants (curcumin [CUM] and caffeic acid [CAF]), focusing on how these antioxidants could reduce cytotoxicity induced by short term secondhand exposure of waterpipe tobacco smoking. Forty-eight adult male BALB/c albino mice were equally divided into four groups. Antioxidants were delivered intraperitoneally, and the exposure to waterpipe smoking (WPS) was performed using a smoking machine. This experiment lasts for 14 consecutive days. Serum were collected from mice before dissection to quantify the activity of some liver enzymes, kidney function tests and proinflammatory cytokines. Lung, heart, and kidney were isolated and processed for light microscopy technique. Parallel treatment of CUM or CAF along with exposure to WPS showed less inflammation, less vacuolized, and more inflated alveoli, less deteriorations in cortex part of kidney, and less disintegration of cardiac myofibers in comparison to waterpipe only. Besides, CUM and CAF significantly reduced the activity of aspartate aminotransferase and proinflammatory cytokines. CUM and CAF were found to have anti-inflammatory and ameliorative effects against the cytotoxicity induced by exposure to waterpipe tobacco smoking, and CUM showed better chemopreventive activity than CAF.

Effect of smoking cessation on chronic waterpipe smoke inhalation-induced airway hyperresponsiveness, inflammation, and oxidative stress

Waterpipe smoking (WPS) prevalence is increasing globally. Clinical and laboratory investigations reported that WPS triggers impairment of pulmonary function, inflammation, and oxidative stress. However, little is known if smoking cessation (SC) would reverse the adverse pulmonary effects induced by WPS. Therefore, we evaluated the impact of WPS inhalation for 3 mo followed by 3 mo of SC (air exposure) compared with those exposed for either 3 or 6 mo to WPS or air (control) in C57BL/6 mice. To this end, various physiological, biochemical, and histological endpoints were evaluated in the lung tissue. Exposure to WPS caused focal areas of dilated alveolar spaces and foci of widening of interalveolar spaces with peribronchiolar moderate mixed inflammatory cells consisting of lymphocytes, macrophages, and neutrophil polymorphs. The latter effects were mitigated by SC. Likewise, SC reversed the increase of airway resistance and reduced the increase in the levels of myeloperoxidase, matrix metalloproteinase 9, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-α, interleukin (IL)-6, and IL-1β in lung tissue induced by WPS. In addition, SC attenuated the increase of oxidative stress markers including 8-isoprostane, glutathione, and catalase induced by WPS. Similarly, DNA damage, apoptosis, and the expression of NF-κB in the lung induced by WPS inhalation were alleviated by CS. In conclusion, our data demonstrated, for the first time, to our knowledge, that SC-mitigated WPS inhalation induced an increase in airway resistance, inflammation, oxidative stress, DNA injury, and apoptosis, illustrating the benefits of SC on lung physiology.

Oxidative Stress and Inflammation Induced by Waterpipe Tobacco Smoking Despite Possible Protective Effects of Exercise Training: A Review of the Literature

The prevalence of waterpipe tobacco smoking (WTS), which is also known as ghalyan, shisha or hookah, is increasing rapidly around the world, especially among youth. Growing interest in this form of tobacco smoking can be traced, in part, to the use of flavored tobacco products, social acceptability as a safer option than cigarettes, and its consideration as a relaxation method or entertainment. However, there is a well-established association between WTS and oxidative stress that causes irreversible chronic pathological conditions such as cardiovascular and respiratory problems, as well as different types of cancers, and thus increases the risk of mortality. Clearly, induction of inflammation status through increased reactive oxygen species (ROS), which in turn leads to oxidative stress and harm to lipids, DNA, and proteins, is the most plausible mechanism to explain the potential harmful effects of WTS. Unlike WTS, well-designed exercise training programs increase ROS to the extent that it is beneficial to the body. In this study, we aimed to review available evidence on the impact of exercise training on oxidative stress and inflammation status. We also summarize the effect of acute and chronic WTS on different exercise capacities.

Evaluation of waterpipe smoke toxicity in C57BL/6 mice model

Waterpipe smoking is a popular pastime worldwide with statistics pointing to an alarming increase in consumption. In the current paper, the evaluation of sub-chronic waterpipe smoke exposure was undertaken using C57BL/6 female mice using a dynamic exposure setting to emulate smoke exposure. Mice were daily subjected to either one (single exposure, SE) or two sessions (double exposure, DE) of waterpipe-generated smoke (two-apple flavor) for a period of two months. Although lungs histopathological examination pointed to a minor inflammation in smoke-exposed mice compared to control air-exposed (CON) group, the lung weights of the waterpipe-exposed mice were significantly higher (+72% in SE and +39% in DE) (p < 0.01) when compared to CON group. Moreover, changes in the protein expression of several proteins such as iNOS and JNK were noted in the lungs of smoke-exposed mice. However, no changes in p38 and EGFR protein levels were noted between the three groups of mice. Our results mainly showed a significant increase in urea serum levels (+28%) in SE mice along with renal pathological damage in both SE and DE mice compared to CON. Additionally, severe significant DNA damages (p < 0.05) were reported in the lungs, kidneys, bone marrow and liver of waterpipe-exposed animals, using MTS and COMET assays. These findings highlighted the significant risks posed by sub-chronic waterpipe smoke exposure in the selected animal model and the pressing need for future better management of waterpipe indoor consumption.

Effect of waterpipe tobacco smoke exposure on the development of metabolic syndrome in adult male rats

The prevalence of metabolic syndrome is increased worldwide. Tobacco smoking increases the risk of developing metabolic syndrome. Waterpipe tobacco smoking has become a global trend of tobacco consumption and is as common as cigarette smoking. In this study, the effect of waterpipe tobacco smoke (WTS) on the development of metabolic syndrome in rats was evaluated. Adult Wistar rats were exposed for 19 weeks to either fresh air (control) or WTS for 1 hour daily/ 5 days per week (WTS). Central obesity, systolic blood pressure, lipid profile, glucose hemostasis and levels of leptin and adiponectin were evaluated. The WTS exposure increased body weight, abdominal circumference, systolic blood pressure and fasting glucose compared to control animals (P<0.05), consistent with inducing metabolic syndrome. The retroperitoneal fat, lipid profile and levels of insulin, leptin and adiponectin were not affected by WTS exposure (P>0.05). In conclusion, exposure to WTS has detrimental health effects leading to the development of metabolic syndrome in experimental animals.

Longitudinal pathways of exclusive and polytobacco hookah use among youth, young adults and adults in the USA: findings from the PATH Study Waves 1-3 (2013-2016)

OBJECTIVE

The goal of this study is to examine cross-sectional rates of use and longitudinal pathways of hookah use among US youth (ages 12-17), young adults (ages 18-24), and adults 25+ (ages 25 and older).

DESIGN

Data were drawn from the first three waves (2013-2016) of the Population Assessment of Tobacco and Health Study, a nationally representative, longitudinal cohort study of US adults and youth. Respondents with data at all three waves (youth, n=11 046; young adults, n=6478; adults 25+, n=17 188) were included in longitudinal analyses.

RESULTS

Young adults had higher ever, past 12-month (P12M) and past 30-day cross-sectional prevalence of hookah use at each wave than youth or adults 25+. The majority of Wave 1 (W1) hookah users were P12M users of other tobacco products (youth: 73.9%, young adults: 80.5%, adults 25+: 83.2%). Most youth and adult W1 P12M hookah users discontinued use in Wave 2 or Wave 3 (youth: 58.0%, young adults: 47.5%, adults 25+: 63.4%). Most W1 P12M hookah polytobacco users used cigarettes (youth: 49.4%, young adults: 59.4%, adults 25+: 63.2%) and had lower rates of quitting all tobacco than exclusive hookah users or hookah polytobacco users who did not use cigarettes.

CONCLUSIONS

Hookah use is more common among young adults than among youth or adults 25+. Discontinuing hookah use is the most common pathway among exclusive or polytobacco hookah users. Understanding longitudinal transitions in hookah use is important in understanding behavioural outcomes at the population level.

Changes at global and site-specific DNA methylation of MLH1 gene promoter induced by waterpipe smoking in blood lymphocytes and oral epithelial cells

Objective: Cigarette tobacco smoking has been shown to cause cancer through different mechanisms that include epigenetic modulation of tumor-suppressor genes. In the present study, the association between global and MLH1 gene promoter methylation and waterpipe tobacco smoking was investigated. Materials and Methods: Blood lymphocytes and oral epithelium were sampled from 150 pure waterpipe smokers and 150 never-smokers from Jordan. Methylation assessment was performed using the methylation-specific PCR technique for MLH1 gene and ELISA for global DNA methylation. Results: Significant increases were shown in global DNA methylation as measured in blood lymphocytes (p < 0.01). In addition, increases in MLH1 gene promoter methylation among waterpipe smokers compared to nonsmokers (p < 0.001) in both oral epithelium and blood lymphocytes was also observed. In addition, strong correlation was found between LWDS-10J dependence score and magnitude of promoter specific methylation of MLH1 (r2 = 0.74-0.78, p < 0.001). Moreover, the percentage of methylated MLH1 promoter was not affected by age or gender (p > 0.05). Discussion and Conclusion: Collectively, the results indicate that waterpipe tobacco use is associated with epigenetic changes that might predispose users to lung and blood cancers. The results highlight the need for actions to discourage waterpipe smoking and can be used in cessation interventions that target this type of smoking.

Systemic Inflammatory Markers Among Waterpipe Smokers, Cigarette Smokers, and Nonsmokers

OBJECTIVE

To determine the levels of neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) among exclusive groups of waterpipe (WP) smokers, cigarette smokers, and nonsmokers.

METHODS

This cross-sectional study was conducted among adults, apparently healthy individuals, aged between 18 and 40 years of either gender. NLR and PLR as measures of systemic inflammation were studied in association with individuals' sociodemographic, health, and tobacco use related characteristics. The results of linear and logistic regression models were reported as crude and adjusted beta coefficients and odds ratios with 95% confidence intervals (CIs).

RESULTS

Out of 190 participants, 34.2% (n = 65) exclusively smoked WP, 32.6% (n = 62) smoked cigarettes, and 33.2% (n = 63) were nonsmokers. The mean NLR and PLR were significantly higher among WP smokers when compared with nonsmokers; however, the comparison between WP smokers and cigarette smokers for both NLR and PLR was not statistically significant. The odds of raised NLR was 4.40 times higher (AOR = 4.40, 95% CI = 1.97, 9.85), and the odds of raised PLR was 3.48 times higher (AOR = 3.48, 95% CI = 1.60, 7.57) for WP smokers compared to nonsmokers.

CONCLUSIONS

WP smoking has a significant association with systemic inflammation as measured by NLR and PLR. The study and existing evidence implicate an urging need to regulate WP industry and its policies.

Waterpipe Tobacco Smoke Inhalation Triggers Thrombogenicity, Cardiac Inflammation and Oxidative Stress in Mice: Effects of Flavouring

The consumption of water-pipe smoking (WPS) has been promoted by the use of flavoured tobacco. However, little is known about the impact of flavouring on the cardiovascular toxicity induced by WPS inhalation. Here, we compared the cardiovascular effects and underlying mechanism of actions of plain (P) (unflavoured) versus apple-flavoured (AF) WPS (30 minutes/day, 5 days/week for 1 month) in mice. Control mice were exposed to air. Both P- and AF-WPS inhalation induced an increase in systolic blood pressure, thrombogenicity and plasma concentration of fibrinogen and von Willebrand factor. In heart homogenates, AF-WPS inhalation caused an increase of 8-isoprostane and a decrease in the levels of reduced glutathione (GSH) and superoxide dismutase (SOD). Nevertheless, P-WPS decreased only the activity of SOD. The concentrations of tumour necrosis factor α and interleukin 1β were increased only in heart homogenates of mice exposed to AF-WPS. Although both P- and AF-WPS increased the concentration of troponin I in heart homogenates and induced DNA damage, the concentration of cleaved caspase 3 was only increased in mice exposed to AF-WPS. Immunohistochemical analysis of the hearts showed that both P- and AF- WPS inhalation decreased the expression of SOD. Moreover, the expression of nuclear factor erythroid-derived 2-like 2 at nuclear level in the heart was higher in both AF-WPS and P-WPS compared with control group, and the effect observed in AF-WPS group was more significant than that seen in P-WPS group. Likewise, the concentration of heme oxygenase-1 was significantly increased in both P-WPS and AF-WPS groups compared with control group, and the effect seen in AF-group was higher than that observed in P-WPS group. In conclusion, our findings showed that both P- and AF-WPS induce thrombogenicity and cardiac injury, and that this toxicity is potentiated by the presence of flavouring.

Short-Term Exposure to Waterpipe/Hookah Smoke Triggers a Hyperactive Platelet Activation State and Increases the Risk of Thrombogenesis

OBJECTIVE

Cardiovascular disease is a major public health problem. Among cardiovascular disease's risk factors, tobacco smoking is considered the single most preventable cause of death, with thrombosis being the main mechanism of cardiovascular disease mortality in smokers. While tobacco smoking has been on the decline, the use of waterpipes/hookah has been rising, mainly due to the perception that they are less harmful than regular cigarettes. Strikingly, there are few studies on the negative effects of waterpipes on the cardiovascular system, and none regarding their direct contribution to thrombus formation. Approach and Results: We used a waterpipe whole-body exposure protocol that mimics real-life human exposure scenarios and investigated its effects, relative to clean air, on platelet function, hemostasis, and thrombogenesis. We found that waterpipe smoke (WPS)-exposed mice exhibited both shortened thrombus occlusion and bleeding times. Further, our results show that platelets from WPS-exposed mice are hyperactive, with enhanced agonist-induced aggregation, dense and α-granule secretion, αIIbβ3 integrin activation, phosphatidylserine expression, and platelet spreading, when compared with clean air-exposed platelets. Finally, at the molecular level, it was found that Akt (protein kinase B) and ERK (extracellular signal-regulated kinases) phosphorylation are enhanced in the WPS and in nicotine-treated platelets.

CONCLUSIONS

Our findings demonstrate that WPS exposure directly modulates hemostasis and increases the risk of thrombosis and that this is mediated, in part, via a state of platelet hyperactivity. The negative health impact of WPS/hookah, therefore, should not be underestimated. Moreover, this study should also help in raising public awareness of the toxic effects of waterpipe/hookah.

Comparative Study on Pulmonary Toxicity in Mice Induced by Exposure to Unflavoured and Apple- and Strawberry-Flavoured Tobacco Waterpipe Smoke

The use of flavoured tobacco products in waterpipe smoking (WPS) has increased its attractiveness and consumption. Nonetheless, the influence of flavourings on pulmonary toxicity caused by WPS remains unclear. Here, the pulmonary toxicity induced by plain (P)-WPS, apple-flavoured (AF)-WPS, and strawberry-flavoured (SF)-WPS (30 minutes/day, 5 days/week for 1 month) was investigated in mice. Control mice were exposed to air. Exposure to P-WPS or AF-WPS or SF-WPS induced a dose-dependent increase of airway hyperreactivity to methacholine. The histological evaluation of the lungs in all the WPS groups revealed the presence focal areas of dilated alveolar spaces and foci of widening of interalveolar spaces with inflammatory cells. In the lung, the activity of neutrophil elastase and myeloperoxidase and the concentrations of tumor necrosis factor-α and glutathione were increased by the exposure to P-WPS, AF-WPS, or SF-WPS. However, the levels of interleukin-6 and catalase were only increased in the AF-WPS and SF-WPS groups, while nitric oxide activity was only increased in the SF-WPS group. DNA injury was increased in all the WPS groups, but the concentration of cleaved caspase-3 was only elevated in the SF-WPS group. The exposure to either P-WPS or AF-WPS or SF-WPS increased the expression of nuclear factor kappa-B (NF-κB) in the lung. In conclusion, the exposure to P-WPS or AF-WPS or SF-WPS induces alterations in lung function and morphology and causes oxidative stress and inflammation via mechanisms that include activation of NF-κB. Overall, the toxicity of flavoured tobacco WPS, in particular SF-WPS, was found to be greater than that of unflavoured WPS.

Salivary Antioxidants Status Following Progressive Aerobic Exercise: What Are the Differences between Waterpipe Smokers and Non-Smokers?

Waterpipe tobacco (WPT) smoking is a public health problem with similar or even stronger effects than cigarette smoking. Although it appears to be associated with extensive oxidative stress, there is a limited number of studies on the oxidative effects of WPT smoking in stressful conditions. We, therefore, compared the responses of salivary flow rate (SFR), uric acid (UA) concentration, and peroxidase (POX) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) activities between WPT smokers and non-smokers following a bout of exhaustive aerobic exercise (AE). Twenty-three sedentary young women (age: 22.95 ± 2.83 years) participated in this study, including 11 smokers (7.00 ± 1.41 uses/week) and 12 non-smokers. All participants were required to perform the Bruce protocol treadmill test at an initial gradient of 10% at 1.7 mph, with increases of these parameters every 3 min until exhaustion. Unstimulated saliva samples were collected before, immediately after, and 1 hour after AE. WPT smokers showed lower SFR compared with non-smokers at all time points (p < 0.05). In comparison to WPT smokers, a larger increase in POX activity (approximately 23% vs. 14%; p = 0.009) and a smaller decline in DPPH activity (approximately -8% vs. -15%; p = 0.004) were found in non-smokers compared with WPT smokers. While these changes were slowly compensated within 1 hour after exhaustion, the activity of both markers was different from the pre-exercise values (p < 0.001). There was also a trend for UA concentration in non-smokers to be higher during the recovery period, with no significant difference between the groups (p > 0.05). It seems that WPT smoking is associated with negative effects on important human antioxidants and a diminished antioxidative response following acute exercise.

The effects of hookah/waterpipe smoking on general health and the cardiovascular system

Hookah or waterpipe smoking or use is an emerging trend in the US population, especially among the youth. The misperception of hookah being less harmful than cigarettes and the availability of different but "appealing" flavors are considered among the main reasons for this trend. Hookah users however are exposed to many of the same toxic compounds/by-products as cigarette users, but at dramatically higher levels, which might lead to more severe negative health effects. In fact, hookah users are at risks of infections, cancers, lung disease, and other medical conditions. Moreover, because of the overlapping toxicant/chemical profile to conventional cigarettes, hookah smoke effects on the cardiovascular system are thought to be comparable to those of conventional cigarettes. A major source of tobacco addiction is nicotine, whose levels in hookah are extremely variable as they depend on the type of tobacco used. Taken together, in this review of literature, we will provide insights on the negative health effects of hookah in general, with a focus on what is known regarding its impact on the cardiovascular system.

Waterpipe tobacco smoke: Characterization of toxicants and exposure biomarkers in a cross-sectional study of waterpipe employees

INTRODUCTION

Few studies have comprehensively characterized toxic chemicals related to waterpipe use and secondhand waterpipe exposure. This cross-sectional study investigated biomarkers of toxicants associated with waterpipe use and passive waterpipe exposure among employees at waterpipe venues.

METHOD

We collected urine specimens from employees in waterpipe venues from Istanbul, Turkey and Moscow, Russia, and identified waterpipe and cigarette smoking status based on self-report. The final sample included 110 employees. Biomarkers of exposure to sixty chemicals (metals, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), nicotine, and heterocyclic aromatic amines (HCAAs)) were quantified in the participants' urine.

RESULTS

Participants who reported using waterpipe had higher urinary manganese (geometric mean ratio (GMR): 2.42, 95% confidence interval (CI): 1.16, 5.07) than never/former waterpipe or cigarette smokers. Being exposed to more hours of secondhand smoke from waterpipes was associated with higher concentrations of cobalt (GMR: 1.38, 95% CI: 1.10, 1.75). Participants involved in lighting waterpipes had higher urinary cobalt (GMR: 1.43, 95% CI: 1.10, 1.86), cesium (GMR: 1.21, 95% CI: 1.00, 1.48), molybdenum (GMR: 1.45, 95% CI: 1.08, 1.93), 1-hydroxypyrene (GMR: 1.36, 95% CI: 1.03, 1.80), and several VOC metabolites.

CONCLUSION

Waterpipe tobacco users and nonsmoking employees of waterpipe venues had higher urinary concentrations of several toxic metals including manganese and cobalt as well as of VOCs, in a distinct signature compared to cigarette smoke. Employees involved in lighting waterpipes may have higher exposure to multiple toxic chemicals compared to other employees.

Effect of Prenatal Waterpipe Tobacco Smoke Exposure on Cardiac Biomarkers in Adult Offspring Rats

Introduction:

The prevalence of waterpipe tobacco smoke (WTS) consumption is increased among pregnant woman. Prenatal cigarette smoke exposure increased the risk of developing cardiovascular diseases in offspring. The current study examined the effect of prenatal WTS exposure on inflammatory profile, oxidative stress, and cardiac biomarkers in adult offspring rats.

Methods:

Female rats received WTS (2 hours per day) or fresh air 1 day prior to mating and throughout the pregnancy period. The body and heart masses were measured in male offspring rats. The level of oxidative stress biomarkers, nitrate, inflammatory mediators (interleukin 6 [IL-6], tumor necrosis factor alpha [TNF-α]), and gene expression of protein kinase C epsilon, angiotensin 2 receptor one, and transforming growth factor beta1 were measured in cardiac tissue homogenates of 13-week-old male offspring rats.

Results:

Prenatal WTS exposure reduced body weight and increased heart to body weight ratio ( P < .05). Prenatal WTS exposure did not affect oxidative stress biomarkers (superoxide dismutase, glutathione peroxidase, and thiobarbituric acid reactive substances) but significantly increased catalase activity and nitrate level ( P < .05) in cardiac tissue of adult male offspring rats. In addition, prenatal exposure to WTS did not affect cardiac level of TNF-α and IL-6 as well as the gene expression of different cardiac modulators in adult male offspring rats ( P > .05).

Conclusion:

Prenatal WTS exposure has detrimental consequences on adult offspring rats by increasing the ratio of heart to body mass, increasing the catalase activity and nitrate level in cardiac tissue of adult male offspring rats.

Waterpipe Smoke Exposure Triggers Lung Injury and Functional Decline in Mice: Protective Effect of Gum Arabic

The prevalence of waterpipe (shisha) tobacco smoking has recently seen a substantial increase worldwide and is becoming a public health problem. Both human and animal studies have established that waterpipe smoke (WPS) increases airway reactivity and inflammation. Gum Arabic (GA) is a prebiotic agent that possesses antioxidant and anti-inflammatory properties. However, its effects on lung toxicity induced by WPS exposure are unknown. Thus, the aim of this study was to investigate the possible salutary effects and underlying mechanisms of GA on WPS-induced pulmonary pathophysiologic effects. C57BL/6 mice were exposed to air or WPS (30 minutes/day for one month) with or without GA treatment in drinking water (15%, w/v). Exposure to WPS induced an influx of neutrophil polymorphs in the peribronchiolar and interstitial spaces and an increase of tumor necrosis factor-α and 8-isoprostane, a marker of lipid peroxidation, concentrations in lung homogenates. The latter effects were significantly mitigated by GA treatment. Likewise, the lung DNA damage induced by WPS exposure was prevented by GA administration. Western blot analysis of the lung showed that GA inhibited nuclear factor kappa-B (NF-κB) expression caused by WPS and augmented that of nuclear factor erythroid 2-related factor 2 (Nrf2). Similarly, immunohistochemical analysis of bronchial epithelial cells and alveolar cells showed a parallel and significant increase in the nuclear expression of Nrf2 and cytoplasmic expression of glutathione in mice treated with GA and exposed to WPS. Moreover, GA administration has significantly prevented airway hyperreactivity to methacholine induced by WPS. We conclude that GA administration significantly declined the physiological, histological, biochemical, and molecular indices of lung toxicity caused by WPS exposure, indicating its beneficial respiratory impact. Considering that GA is a safe agent with health benefits in humans, our data suggest its potential usage in waterpipe smokers.

Effect of waterpipe tobacco smoke exposure during lactation on learning and memory of offspring rats: Role of oxidative stress

AIMS

The prevalence of waterpipe tobacco smoking is increasing among breastfeeding women. Herein, the effect of maternal waterpipe tobacco smoke (WTS) exposure during lactation on learning and memory of adult offspring rats was examined.

MAIN METHODS

Lactating rats received either fresh air or mainstream WTS (1 h twice daily) from day 4 to day 21. Learning and memory was examined by the radial arm water maze and the levels of brain derived neurotrophic factor (BDNF) and oxidative stress biomarkers superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase and thiobarbituric acid reactive substances (TBARS) were assessed in the hippocampus of adult male offspring rats.

KEY FINDINGS

Maternal exposure to WTS during lactation impaired the long-term memory and reduced levels of BDNF (P < 0.05) in hippocampus in adult male offspring rats. The activity of SOD, GPx and catalase were reduced (P < 0.05) while level of TBARS was increased (P < 0.05).

SIGNIFICANCE

Maternal WTS exposure during lactation impaired the long-term memory of adult male offspring that was associated with low levels of BDNF and altered oxidative stress balance. Therefore, careful measures should be taken to enhance waterpipe smoking cessation during breastfeeding.

Waterpipe smoke and e-cigarette vapor differentially affect circadian molecular clock gene expression in mouse lungs

The use of emerging tobacco products, such as waterpipe or hookah and electronic cigarettes (e-cigs), has gained significant popularity and are promoted as safer alternatives to conventional cigarettes. Circadian systems are internal biological oscillations that are considered important regulators of immune functions in mammals. Tobacco induced inflammatory lung diseases frequently exhibit time-of-day/night variation in lung function and symptom severity. We investigated the impact of inhaled e-cig vapor and waterpipe smoke (WPS) on pulmonary circadian molecular clock disruption by determining the changes in expression levels and abundance of core clock component genes (BMAL1, CLOCK) and clock-controlled output genes (Rev-erbα, Per2, Rev-erbβ, Cry2, Rorα) in mouse lungs. We showed that the expression levels of these pulmonary core clock genes and clock-controlled output genes were altered significantly following exposure to WPS (Bmal1, Clock, and Rev-erbα). We further showed a significant yet differential effect on expression levels of core clock and clock-controlled genes (Bmal1, Per2) in the lungs of mice exposed to e-cig vapor containing nicotine. Thus, acute exposure to WPS and e-cig vapor containing nicotine contributes to altered expression of circadian molecular clock genes in mouse lungs, which may have repercussions on lung cellular and biological functions.

Epidemiology and Adverse Consequences of Hookah/Waterpipe Use: A Systematic Review

Hookah smoking is becoming a popular trend globally. Waterpipe smoking is the second most prevalent form of alternate tobacco products. The rapid increase in hookah use is because of the misconception prevalent in society that hookah smoking is less harmful than cigarette smoking. Smoking ban policies had given impetus of switching from cigarette smoking to alternate tobacco products like waterpipe. Hookah users regard hookah to be more socially acceptable, less stigmatizing with flavors and to alleviate cigarette craving symptoms. Newer basic science research on animal models and human cells has shown consistently mutagenic, oxidative, and inflammatory changes that could cause possible health effects of premalignant oral lesion and chronic diseases like atherosclerosis and chronic obstructive pulmonary disease. Studies on the chemistry of waterpipe smoke had shown alarming results with the smoke containing seven carcinogens, 39 central nervous system depressants, and 31 respiratory irritants. Enormous data exist showing waterpipe smoking causing various health effects. Hookah smoking effects on cardiovascular disease is additive with hookah containing a significant amount of nicotine, tar, and heavy metals causing both acute and chronic effects on the cardiovascular system. These effects include increased heart rate, blood pressure, prevalence of coronary heart disease, heart failure, ST-segment elevation myocardial ischemia, recurrent ischemia, and worse outcomes including mortality related to these diseases. The objectives of the review are to assess the factor associated with the increasing use of hookah, its health effects, options for hookah smoking cessation, and public health policy initiatives to mitigate waterpipe use.

Evaluation of the impact of waterpipe tobacco smoke exposure on the activity and expression of rat hepatic CYP450: a pharmacokinetic study

Waterpipe smoke contains many toxic constituents that can alter drug pharmacokinetics. This study assessed the effect of waterpipe smoke exposure on the activity and expression of CYP450 enzymes in rats. Animals (n = 10/group) were exposed to either waterpipe smoke or side-stream cigarette smoke for 1 h/day (6 days/week) for 31 days, or fresh air (control). An intragastric cocktail solution containing three probe drugs, phenacetin, chlorzoxazone and testosterone was administered to assess the activity of CYP1A2, CYP2E1 and CYP3A, respectively. Serum concentrations were determined using LC-MS/MS and the pharmacokinetic parameters were calculated. The mRNA expression of hepatic enzymes was also quantified. Waterpipe and cigarette smoke exposure did not significantly alter the pharmacokinetics of phenacetin, chlorzoxazone and testosterone. For example, the clearance and drug exposure values were comparable among groups for all probe drugs. Additionally, there was no significant effect of waterpipe and cigarette smoke on mRNA expression of hepatic CYP1A2, CYP2E1 and CYP3A2. The results demonstrate that waterpipe smoke exposure had no effect on the functional expression of three key CYP450 isoforms in rats. Future research is required with longer exposure periods to waterpipe smoke. Such work serves to enhance current understanding of effect of waterpipe smoke exposure on pharmacokinetics.

Waterpipe Smoking Is Associated with Changes in Fibrinogen, FVII, and FVIII Levels

Cigarette smoking has been shown to be associated with changes in coagulation factors in the circulation and the subsequent thrombosis development. In this study, the impact of waterpipe smoking on the levels of fibrinogen, factor VII (FVII), and factor VIII (FVIII) was investigated. In addition, the effects of waterpipe smoking were compared to those of cigarette smoking and never smokers. A total of 80 male smokers (40 cigarette smokers and 40 waterpipe smokers) and 40 apparently healthy never smokers were recruited in the study. Both waterpipe smoking and cigarette smoking induced significant increases in the plasma levels of fibrinogen, factor VII, and factor VIII (p < 0.01). The magnitude of the increase in fibrinogen levels induced by waterpipe smoking was higher than that induced by cigarette smoking (p < 0.01), while similar increases were observed in other factors (p > 0.05). In addition, in the waterpipe group, the magnitude of the increase in fibrinogen and factor VIII was higher in the smokers with more than 3 years of use (p < 0.05). In conclusion, similar to cigarette smoking, waterpipe smoking modulates the levels of coagulation factors, suggesting its thrombotic potential.

Plasma and saliva levels of three metals in waterpipe smokers: a case control study

In this case-control study, the influence of waterpipe tobacco smoking on the plasma and saliva levels of cadmium, lead and zinc was examined in participants who were waterpipe tobacco smokers (WS) or never-smokers (NS). The concentration of metals was higher in WS relative to NS. The mean (SEM) cadmium concentration in plasma was 3.3 (0.18) µg/dL in WS versus 0.82 (0.09) µg/L in NS (p < .001) and in saliva was 5.1 (0.36) µg/L in WS versus 0.64 (0.2) µg/L in NS (p < .001). The mean (SEM) lead concentration in plasma was 5.2 (0.25) µg/dL in WS versus 3.4 (0.41) µg/dL in NS (p < .01) and in saliva was 4.8 (0.58) µg/L in WS versus 2.8 (0.27) µg/L in NS (p < .05). Similarly, a significant difference in zinc concentration was observed, with a mean of 2.0 (0.17) µg/mL in WS plasma versus 1.49 (0.16) µg/mL in NS (p < .05) and a mean 0.94 (0.07) µg/mL in WS saliva versus 0.45 (0.06) µg/mL in NS (p < .01). In conclusion, waterpipe tobacco smoking is associated with elevated levels of metals in body fluids. These results provide another demonstration of how waterpipe tobacco smoking exposes smokers to harmful toxicants.

Cardiac effects of cigarette tobacco smoking in rat model of diabetes

AIMS

Tobacco smoking is considered a global health issue, contributing to increased risk of cardiovascular disease (CVD) and diabetes (DM). We aimed to assess effects of cigarette smoking on cardiac inflammation, oxidative stress and fibrosis in rat model of streptozotocin (STZ)-induced diabetes.

MAIN METHODS

Adults Wistar rats were assigned into control (fresh air, intraperitoneal injection (i.p) of citrate buffer), cigarette smoking (1 h daily for 4 weeks, i.p citrate buffer), DM (35 STZ mg/kg single i.p, fresh air), and DM + Smoking groups for 4 weeks. Cardiac biomarkers of oxidative stress, inflammation, and fibrosis were evaluated.

KEY FINDINGS

STZ-induced diabetes as documented by the persistent increase in blood glucose. Relative to control, a significant decrease in body weight was observed in diabetic groups paralleled with increased heart to body weight ratio and systolic blood pressure in all groups. Levels of total nitrite, thiobarbituric acid substances, endothelin -1, interleukin-6 and myeloperoxidase were increased in the DM, Smoking and DM + Smoking groups without changes in C-reactive protein. Cardiac levels of GSH were increased in Smoking groups whereas activities of catalase and superoxide dismutase increased in DM, Smoking and DM + Smoking groups. DM but not smoking increased cardiac fibrosis with a parallel increase in transforming growth factor beta. Cardiac levels of matrix metalloproteinase-2 were elevated in Smoking groups and decreased in DM.

SIGNIFICANCE

Exposure to cigarette smoke may increase risk of CVD in DM by increased cardiac oxidative stress and inflammation. Smoking was associated with increased oxidant enzymes and metalloproteinase-2 probably to prevent cardiac fibrosis.

Effect of prenatal waterpipe tobacco smoke on airway inflammation in murine model of asthma of adult offspring mice

OBJECTIVE

Worldwide popularity of waterpipe tobacco smoking has increased, including in pregnant women. This study investigates the effect of prenatal waterpipe tobacco smoke (WTS) exposure on airway inflammation in a murine model of asthma of adult offspring mice.

MATERIALS AND METHODS

Pregnant BALB/c mice were exposed to fresh air or WTS, using a whole-body exposure system that mimics human use during WTS. Adult male offspring mice were divided into; (1) control (prenatal fresh air, postnatal ovalbumin sensitization and saline challenge), (2) postnatal Ova S/C (prenatal fresh air, postnatal ovalbumin sensitization and challenge (Ova S/C)), (3) prenatal WTS (prenatal WTS, postnatal ovalbumin sensitization and saline challenge) and (4) prenatal WTS + postnatal Ova S/C. Cells from the bronchoalveolar lavage fluid, cytokines, and oxidative stress markers (superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and thiobarbituric acid reactive substances (TBARS)) from lung homogenates were evaluated.

RESULTS

Prenatal WTS increased recruitment of cells in lungs and levels of SOD and catalase when compared to unexposed offspring's. The levels of cytokines, GPx and TBARS were not affected by prenatal WTS. Prenatal WTS exposure and postnatal Ova S/C increased airway inflammation and activity of SOD compared to control and Ova S/C mice and reduced IL-18 levels compared to Ova S/C mice.

DISCUSSION AND CONCLUSIONS

Prenatal exposure to WTS induced airway inflammation, further enhanced by a murine model of asthma in adult offspring. Prenatal exposure to WTS adversely affects the lung function of the offspring and careful strategies for increasing public awareness regarding the harmful effects of WTS during pregnancy is important.