Genotoxic impact of long-term cigarette and waterpipe smoking on DNA damage and oxidative stress in healthy subjects

Does waterpipe smoke induce genotoxicity (DNA damage) in mammalian cells in vivo? A systematic review

The waterpipe works by placing tobacco in a bowl with holes at the bottom, which is connected to a tube leading to a water-filled container. Upon heating the tobacco product with hot charcoal placed atop it, the emanating smoke is inhaled by the user via a hose linked to the water receptacle. The aim of this literature review is to evaluate whether the use of waterpipes can indeed induce genotoxicity in mammalian cells in vivo. Additionally, the study aims to assess the quality of the included research articles on this topic to ensure the reliability of the findings. We performed comprehensive searches in PubMed, SCOPUS, and Web of Science to identify relevant articles published until July 2024. The findings confirmed that waterpipe smoke induces genetic damage. This assertion is supported by the fact that 11 studies (out of 15) received a Strong or Moderate assessment categorization, suggesting that the majority of studies adhered to most technical standards, thereby enhancing the reliability of the research findings. Regarding the types of DNA damage reported, DNA strand breaks, chromosome damage and oxidative DNA damage were found in this review. Taken together, this study holds significant importance in assessing the efficacy of genotoxicity assays in detecting DNA damage due to waterpipe smoke and the comet and micronucleus assays are suitable biomarkers for biomonitoring people who use waterpipe.

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.

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.

Biomarkers of Waterpipe Tobacco Smoke Exposure: A Systematic Review and Meta-Analysis

INTRODUCTION

The prevalence of waterpipe tobacco smoking is increasing globally. Biomarkers of waterpipe tobacco smoke (WTS) exposure are less studied.

AIMS AND METHODS

To identify the types of biomarkers of WTS exposure and estimate changes in biomarker concentrations pre- to post-WTS exposure. PubMed, Embase, Web of Science, CINAHL Plus, PsycINFO, and Cochrane Library were searched for studies up to April 24, 2023. The types of biomarkers were identified. Random-effects models were used to estimate changes in biomarker concentrations pre- to post-WTS exposure.

RESULTS

Seventy-three studies involving 3755 participants exposed to WTS (49% male, mean age: 24.8 years) and 11 types of biomarkers of WTS exposure were identified. The biomarkers included tobacco alkaloids, expired carbon monoxide (eCO), carboxyhemoglobin (COHb), tobacco-specific nitrosamines, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, unmetabolized VOCs, unmetabolized PAHs, furan metabolites, and heterocyclic aromatic amines. Compared with pre-WTS exposure, eCO (breath; mean difference [MD] 27.00 ppm; 95% confidence interval [CI]: 20.91 to 33.08), COHb (blood; MD 4.30%; 95%CI: 2.57 to 6.03), COHb (breath; MD 7.14%; 95%CI: 4.96 to 9.31), nicotine (blood; MD 8.23 ng/mL; 95%CI: 6.27 to 10.19), and cotinine (urine; MD 110.40 ng/mL; 95%CI: 46.26 to 174.54) significantly increased post-WTS exposure.

CONCLUSIONS

Biomarkers of WTS exposure were systematically identified. The similarity between the biomarkers of WTS exposure and those of cigarette smoke and higher concentrations of some biomarkers post-WTS exposure underscore the need for further research on applying biomarkers in surveillance, interventions, and regulations to mitigate the harms of waterpipe tobacco smoking.

IMPLICATIONS

This study provides the first comprehensive overview of biomarkers investigated and available for assessing WTS exposure and their concentration changes in the human body. Researchers can use biomarkers such as eCO, COHb, nicotine, and cotinine to measure the health risks associated with WTS exposure and objectively evaluate the effectiveness of public health interventions aimed at reducing waterpipe tobacco smoking. Public health policymaking can also be informed through increased biomarker concentrations following WTS exposure, to implement regulations and public health education campaigns on limiting or preventing waterpipe tobacco smoking.

Impact of prolonged exposure to occasional and regular waterpipe smoke on cardiac injury, oxidative stress and mitochondrial dysfunction in male mice

Regular waterpipe smoking (Reg-WPS) is well recognized for its deleterious effect on the heart. However, there is a paucity of experimental studies on the impact of occasional waterpipe smoking (Occ-WPS), also known as nondaily smoking, versus Reg-WPS on cardiac homeostasis, and the mechanisms underlying these effects. Hence, we aimed, in the present study, to investigate the effect of Occ-WPS (30 min/day, 1 day/week) versus Reg-WPS (30 min/day, 5 days/week) for 6 months on systolic blood pressure (SBP), cardiac injury, oxidative markers, chemokines, proinflammatory cytokines, DNA damage and mitochondrial function compared with air (control) exposed mice. Our results show that SBP was increased following exposure to either Occ-WPS or Reg-WPS compared with air-exposed mice. Moreover, we found that only Reg-WPS induced a significant elevation in the levels of troponin I, brain natriuretic peptide, lactate dehydrogenase, and creatine phosphokinase. However, the atrial natriuretic peptide (ANP) was significantly increased in both Occ-WPS and Reg-WPS groups. Compared with air-exposed mice, the levels of lipid peroxidation, reduced glutathione and monocyte chemoattractant protein-1 were only significantly augmented in the Reg-WPS. However, catalase, superoxide dismutase, and CXCL1 were significantly increased in both Occ-WPS and Reg-WPS. The concentrations of the adhesion molecules E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 were solely elevated in the heart of mice exposed to Reg-WPS. Similarly, the concentrations of interleukin-1β and tumor necrosis factor α were only significantly augmented in the Reg-WPS. However, both Occ-WPS and Reg-WPS triggered significant augmentation in the levels of IL17 and DNA damage compared to the control groups. Furthermore, while Occ-WPS induced a slight but statistically insignificant elevation in the concentrations of mammalian targets of rapamycin and nuclear factor erythroid-derived 2-like 2 (Nrf2) expression, Reg-WPS exposure increased their levels substantially, in addition to p53 and mitochondrial complexes II & III, and IV activities compared with air-exposed mice. In conclusion, our findings show that while the long-term Occ-WPS exposure induced an elevation of SBP, ANP, antioxidant enzymes, IL17, CXCL1, and cardiac DNA damage, Reg-WPS exposure was consistently associated with the elevation of SBP and occurrence of cardiac damage, inflammation, oxidative stress, DNA damage and mitochondrial dysfunction.

Human biomonitoring of environmental contaminants in Gulf Countries - current status and future directions

BACKGROUND

This systematic review aimed to evaluate the status of Human Biomonitoring (HBM) in the Gulf Cooperation Council (GCC) region and provide recommendations for future research, considering the increased environmental contaminants that pose a threat to human health in this rapidly industrializing area.

METHODS

A thorough search was performed in PubMed and Web of Science databases up to February 2023 to identify biomonitoring studies on human exposure and levels in the GCC region. Two independent reviewers assessed study eligibility, conducted data extraction and risk of bias assessment. The NIH Quality Assessment Tools and PRISMA guidelines were utilized for quality evaluation and reporting of results.

RESULTS

A total of 38 eligible articles were included in this systematic review out of 662 articles screened. The majority of the publications were from Saudi Arabia (n = 24) and Kuwait (n = 10), while limited representation was found from Qatar (n = 3) and the UAE (n = 1). No articles were identified from Oman and Bahrain. The studies focused on metals, organohalogen compounds, pesticides, polycyclic aromatic hydrocarbons, and phthalates. The findings revealed elevated levels of metals and established correlations between metal exposure and adverse health effects, including infant neurodevelopmental issues, vitamin D deficiency, and oxidative stress. The presence of organohalogen compounds and pesticides was prevalent in the GCC region, with significant associations between exposure to these compounds and negative health outcomes. Notably, high levels of perchlorate were observed in the Kuwaiti population, and a study from Saudi Arabia found an association between per- and polyfluorinated substances and increased odds of osteoporosis.

CONCLUSIONS

This review emphasizes the need to address environmental health challenges in the GCC region through improved HBM research methods and strategies. Implementing biomonitoring programs, conducting cohort studies, investing in tools and expertise, promoting collaboration, and engaging the community are crucial for reliable HBM data in the GCC.

The PIG-A gene mutation assay in human biomonitoring and disease

The blood cell phosphatidylinositol glycan class A (PIG-A) gene mutation assay has been extensively researched in rodents for in vivo mutagenicity testing and is now being investigated in humans. The PIG-A gene is involved in glycosyl phosphatidylinositol (GPI)-anchor biosynthesis. A single mutation in this X-linked gene can lead to loss of membrane-bound GPI anchors, which can be enumerated via corresponding GPI-anchored proteins (e.g., CD55) using flow cytometry. The studies published to date by different research groups demonstrate a remarkable consistency in PIG-A mutant frequencies. Moreover, with the low background level of mutant erythrocytes in healthy subjects (2.9-5.56 × 10-6 mutants), induction of mutation post genotoxic exposure can be detected. Cigarette smoking, radiotherapy, and occupational exposures, including lead, have been shown to increase mutant levels. Future applications of this test include identifying new harmful agents and establishing new exposure limits. This mutational monitoring approach may also identify individuals at higher risk of cancer development. In addition, identifying protective agents that could mitigate these effects may reduce baseline somatic mutation levels and such behaviors can be encouraged. Further technological progress is required including establishing underlying mechanisms of GPI anchor loss, protocol standardization, and the development of cryopreservation methods to improve GPI-anchor stability over time. If successful, this assay has the potential be widely employed, for example, in rural and low-income countries. Here, we review the current literature on PIG-A mutation in humans and discuss the potential role of this assay in human biomonitoring and disease detection.

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.

National and Regional Fraction of Cancer Incidence and Death Attributable to Current Tobacco and Water-Pipe Smoking in the Eastern Mediterranean Countries in 2020

INTRODUCTION

We aimed to calculate the Population Attributable Fraction (PAF) of cancers due to tobacco use in the Eastern Mediterranean Region (EMRO), where water-pipe smoking is prevalent but its effect was not considered in previous studies.

AIMS AND METHODS

We applied Levin's formula to estimate PAFs of cancers due to tobacco use (defined as all type tobacco including both cigarette and water-pipe). We also calculated PAF of water-pipe smoking separately. Exposure prevalence data were retrieved from representative national and subnational surveys. Data on cancer incidence and death were also and cancer cases were obtained GLOBOCAN 2020. We also obtained associated relative risks from published meta-analyses.

RESULTS

Of the total 715 658 incident adult cancer cases that were reported in 2020 in EMRO, 14.6% (n = 104 800) was attributable to tobacco smoking (26.9% [n = 92 753]) in men versus 3.3% (n = 12 048) in women. Further, 1.0% of incident adult cancers were attributable to current water-pipe use (n = 6825) (1.7% [n = 5568]) in men versus 0.4% (n = 1257 in women).

CONCLUSIONS

PAFs of cancers due to tobacco smoking in EMRO were higher in our study than previous reports. This could be due to the neglected role of water-pipe in previous studies that is a common tobacco smoking method in EMRO. The proportion of cancers attributable to water-pipe smoking in EMRO might be underestimated due to lack of research on the risk of cancers associated with water-pipe smoking and also less developed cancer registries in EMRO.

IMPLICATIONS

In this study, we found higher PAFs for cancers due to tobacco smoking in the Eastern Mediterranean (EMR) region than previous reports. This difference could be due to ignoring the role of water-pipe smoking in previous studies. In 2020, 1% of incident cancers and 1.3% of cancer-related deaths in EMRO were attributable to water-pipe smoking. We also found a big difference in PAFs of cancers due to tobacco and water-pipe smoking across EMRO countries, with Tunisia, Lebanon, and Jordan having the highest, and Djibouti, Sudan, and Somalia having the lowest proportions of cancers attributable to tobacco and water-pipe smoking.

Impact of smoking intensities on sleep quality in young Saudi males: a comparative study

This study aimed to compare various components of sleep quality between cigarette smokers of various intensities and non-smokers in young Saudi males. In total, 73 healthy male participants (31 smokers and 42 non-smokers) aged 17-33 years were recruited over three months (August 2018 to October 2018). All participants completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire. The smokers were then divided into three groups, according to their Smoking Index* (SI) (Cigarettes Per Day (CPD) X Years of Tobacco Use), into mild, moderate, and heavy smokers. The PSQI was significantly higher in heavy smokers than in mild smokers (P=0.022) or non-smokers (p=0.013). A significant positive correlation was observed between the PSQI and the smoking index (p=0.005). Sleep duration was significantly longer in heavy smokers compared to mild (p=0.032) and nonsmokers (p=0.047). Sleep disturbance was significantly higher in moderate than nonsmokers (p=0.035) and moderate than mild smokers (p=0.028). Sleep latency was significantly longer in heavy than nonsmokers (p=0.011). Daytime dysfunction was significantly higher in moderate than mild smokers (p=0.041). Habitual sleep efficiency was significantly greater in moderate than in either mild (p=0.013) or nonsmokers (p=0.021). The use of sleep medication was significantly higher in moderate than nonsmokers (p=0.041). The findings suggest that poorer sleep quality is positively associated with smoking intensity among young Saudi males. Considering the importance of sleep quality for well-being and health, these results suggest exploring how improving sleep quality could inform future smoking cessation interventions.

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.

Effects of the intranasal application of gold nanoparticles on the pulmonary tissue after acute exposure to industrial cigarette smoke

Inhalation of harmful particles appears as a primary factor for the onset and establishment of chronic obstructive pulmonary disease (COPD). Cigarette smoke acutely promotes an exacerbated inflammatory response with oxidative stress induction with DNA damage. Administration of Gold Nanoparticles (GNPs) with 20 nm in different concentrations can revert damages caused by external aggravations. The effects of GNPs in a COPD process have not been observed until now. The objective of this work was to evaluate the therapeutic effects of intranasal administration of different doses of GNPs after acute exposure to industrial cigarette smoke. Thirty male Swiss mice were randomly divided into five groups: Sham; cigarette smoke (CS); CS + GNPs 2.5 mg/L; CS + GNPs 7.5 mg/L and CS + GNPs 22.5 mg/L. The animals were exposed to the commercial cigarette with filter in an acrylic inhalation chamber and treated with intranasal GNPs for five consecutive days. The results demonstrate that exposure to CS causes an increase in inflammatory cytokines, histological changes, oxidative and nitrosive damage in the lung, as well as increased damage to the DNA of liver cells, blood plasma and lung. Among the three doses of GNPs (2.5, 7.5, and 22.5 mg/L) used, the highest dose had better anti-inflammatory effects. However, GNPs at a dose of 7.5 mg/L showed better efficacies in reducing ROS formation, alveolar diameter, and the number of inflammatory cells in histology, in addition to significantly reduced rate of DNA damage in lung cells without additional systemic genotoxicity already caused by cigarette smoke.

Genotoxic Effects of Lead and Their Impact on the Expression of DNA Repair Genes

Exposure to lead (Pb) continues to be a significant worldwide problem. Pb is a highly poisonous heavy metal affecting several organ systems in the body. Although Pb has been shown to be genotoxic to experimental animals and humans, the underlying mechanisms are still not understood. An indirect mechanism related to the inhibition of DNA repair systems by Pb has been suggested. Heavy metals can interfere with the activities of several proteins and gene expressions. Recent studies gathered in this review article demonstrated an altered expression of DNA repair genes due to Pb toxicity. However, their findings are conflicting. Furthermore, the interaction of Pb and epigenetic mechanisms regulating gene expression may have a crucial role in the inhibition of DNA repair systems. Therefore, additional studies are needed to evaluate these findings and to obtain a complete picture of the genotoxic properties of Pb and the underlying mechanisms that may have a crucial role in carcinogenesis.

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.

Association between waterpipe smoking and obesity: Population-based study in Qatar

INTRODUCTION

Over the past decade obesity prevalence has been increasing rapidly in the Gulf region (GR) including Qatar, becoming one of the major health issues in the region. Concomitantly, waterpipe (WP) smoking is increasing worldwide especially in the GR, and although the effect of cigarette smoking on body weight is well-established, studies indicating an association between WP smoking and obesity are scarce. Thus, we explored the association between WP smoking and obesity in comparison with cigarette smokers and healthy population in Qatar.

METHODS

We performed a cross-sectional study using data from Qatar Biobank and analyzed anthropometric measurements among 879 adults (aged 18-65 years) that included WP smokers, cigarette smokers, dual smokers and never smokers. Body composition was measured using bioelectrical impedance analysis and reported as lean mass, fat mass, and body fat percentage.

RESULTS

Overall, 12% (n=108) were WP smokers, 22% (n=196) were cigarette smokers, 9% (n=77) smoked both WP and cigarettes and 57% (n=498) were never smokers. Age, sex, history of diabetes, and hypertension, in addition to nationality were considered as confounding factors. Our analysis revealed that WP smokers had a significantly higher BMI (kg/m2) and fat mass when compared with cigarette smokers (p<0.05). Moreover, compared to cigarette smoking, WP smoking had a higher significant effect on BMI (β=3.8, SE=0.38; and β=5.5, SE=0.46; respectively), and fat mass (β=5.1, SE=0.79; and β=9.0, SE=0.97; respectively). However, WP users were similar to never-smokers in terms of body fat percent.

CONCLUSIONS

Our data indicate that compared to never smokers, daily WP users have higher BMI and fat mass, and are likely to be obese.

The adverse health effects of waterpipe smoking in adolescents and young adults: A narrative review

Waterpipe (WP) smoking has rapidly grown in popularity in the United States and other Western countries with the fastest uptake among younger individuals. This growth has been encouraged by the misperception that WP smoke is harmless or less harmful than cigarette smoke. To better understand how WP affects the health of young people, we conducted a narrative review of the literature focusing on the adverse health effects of WP smoking in adolescents and younger adults. We searched scientific literature databases including PubMed, MEDLINE, EMBASE, and ISI Web and selected papers that met the inclusion criteria. Sixty-three papers met the inclusion criteria and were selected for review. Data were abstracted from the selected papers into a standardized table. The evidence demonstrates that WP smoking can cause acute lung infection and injury, and carbon monoxide (CO) poisoning, in adolescents and young adults. It is also associated with adverse subclinical effects in this sub-population, including oral and systemic genotoxicity, lung function decline, and the alteration of vascular and hemodynamic functions. Limited evidence that is available indicates associations with psychological and neurological effects and asthma. No identified publications examined the association between WP use and type 2 diabetes, a condition that is associated with cigarette smoking among young people. WP smoking by younger individuals can result in their hospitalization due to systemic CO poisoning and acute lung disease, and induce subclinical adverse effects in the oral cavity, pulmonary system, and in circulation, that are involved in the pathogenesis of local and systemic chronic diseases.

Comparative Genotoxicity and Mutagenicity of Cigarette, Cigarillo, and Shisha Tobacco Products in Epithelial and Cardiac Cells

Epidemiology studies link cigarillos and shisha tobacco (delivered through a hookah waterpipe) to increased risk for cardiopulmonary diseases. Here we performed a comparative chemical constituent analysis between 3 cigarettes, 3 cigarillos, and 8 shisha tobacco products. The potency for genotoxicity and oxidative stress of each product's generated total particulate matter (TPM) was also assessed using immortalized oral, lung, and cardiac cell lines to represent target tissues. Levels of the carcinogenic carbonyl formaldehyde were 32- to 95-fold greater, while acrolein was similar across the shisha aerosols generated by charcoal heating compared to cigarettes and cigarillos. Electric-mediated aerosol generation dramatically increased acrolein to levels exceeding those in cigarettes and cigarillos by up to 43-fold. Equivalent cytotoxic-mediated cell death and dose response for genotoxicity through induction of mutagenicity and DNA strand breaks was seen between cigarettes and cigarillos, while minimal to no effect was observed with shisha tobacco products. In contrast, increased potency of TPM from cigarillos compared to cigarettes for inducing oxidative stress via reactive oxygen radicals and lipid peroxidation across cell lines was evident, while positivity was seen for shisha tobacco products albeit at much lower levels. Together, these studies provide new insight into the potential harmful effects of cigarillos for causing tobacco-associated diseases. The high level of carbonyls in shisha products, that in turn is impacted by the heating mechanism, reside largely in the gas phase which will distribute throughout the respiratory tract and systemic circulation to likely increase genotoxic stress.

Systems toxicology study reveals reduced impact of heated tobacco product aerosol extract relative to cigarette smoke on premature aging and exacerbation effects in aged aortic cells in vitro

Aging and smoking are major risk factors for cardiovascular diseases (CVD). Our in vitro study compared, in the context of aging, the effects of the aerosol of Tobacco Heating System 2.2 (THS; an electrically heated tobacco product) and 3R4F reference cigarette smoke (CS) on processes that contribute to vascular pathomechanisms leading to CVD. Young and old human aortic smooth muscle cells (HAoSMC) were exposed to various concentrations of aqueous extracts (AE) from 3R4F CS [0.014-0.22 puffs/mL] or THS aerosol [0.11-1.76 puffs/mL] for 24 h. Key markers were measured by high-content imaging, transcriptomics profiling and multianalyte profiling. In our study, in vitro aging increased senescence, DNA damage, and inflammation and decreased proliferation in the HAoSMCs. At higher concentrations of 3R4F AE, young HAoSMCs behaved similarly to aged cells, while old HAoSMCs showed additional DNA damage and apoptosis effects. At 3R4F AE concentrations with the maximum effect, the THS AE showed no significant effect in young or old HAoSMCs. It required an approximately ten-fold higher concentration of THS AE to induce effects similar to those observed with 3R4F. These effects were independent of nicotine, which did not show a significant effect on HAoSMCs at any tested concentration. Our results show that 3R4F AE accelerates aging in young HAoSMCs and exacerbates the aging effect in old HAoSMCs in vitro, consistent with CS-related contributions to the risk of CVD. Relative to 3R4F AE, the THS AE showed a significantly reduced impact on HAoSMCs, suggesting its lower risk for vascular SMC-associated pathomechanisms leading to CVD.

Markers of oxidative stress and toxicant exposure among young waterpipe smokers in the USA

Waterpipe (aka hookah) tobacco smokers are exposed to toxicants that can lead to oxidative DNA and RNA damage, a precursor to chronic disease formation. This study assessed toxicant exposure and biomarkers of DNA [8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG)] and RNA [8-oxo-7,8-dihydroguanosine (8-oxoGuo)] oxidative damage during smoking of flavored and non-flavored waterpipe tobacco. Thirty waterpipe smokers completed two counterbalanced 2-h lab waterpipe smoking sessions (flavored vs. non-flavored waterpipe tobacco). Urinary concentrations of 8-oxodG and 8-oxoGuo and expired carbon monoxide (eCO) were measured before and after the smoking sessions. A significant increase in the urinary concentrations of 8-oxodG (from 2.12 ± 0.83 to 2.35 ± 0.91 ng/mg creatinine, p = 0.024) and 8-oxoGuo (from 2.96 ± 0.84 to 3.45 ± 0.76 ng/mg creatinine, p = 0.003) were observed after smoking the non-flavored and flavored waterpipe tobacco, respectively. Our results also showed that the mean ± SD of eCO increased significantly after smoking the flavored (from 1.3 ± 1.1 to 20.3 ± 23.6 ppm, p < 0.001) and non-flavored waterpipe tobacco (from 1.8 ± 1.2 to 24.5 ± 26.1 ppm, p < 0.001). There were no significant differences in the means of 8-oxodG (p = 0.576), 8-oxoGuo (p = 0.108), and eCO (p = 0.170) between the flavored and non-flavored tobacco sessions. Smoking non-flavored and flavored waterpipe tobacco leads to oxidative stress and toxicant exposure. Our findings add to the existing evidence about the adverse effects of waterpipe tobacco smoking (WTS) and the need for strong policies to inform and protect young people from the risks of WTS.

Evaluation of DNA Damage and Expressions of DNA Repair Gene in Occupationally Lead Exposed Workers (Jodhpur, India)

Occupational exposure to lead (Pb) remains a significant concern for worker's health working in different factories. There are many discrepancies among the results regarding the studies of genotoxicity of Pb. The present study aimed to evaluate DNA damage and expressions of DNA repair genes (OGG1, XRCC1, and XPD) in occupationally Pb-exposed workers of Jodhpur, India. The study consisted of 100 occupationally Pb-exposed workers and 100 controls (non-exposed) with no history of occupational exposure. Pb levels were determined by atomic absorption spectrophotometry, serum 8-hydroxy-2-deoxyguanosine (8-OHdG) concentrations were measured by ELISA, and expressions of DNA repair genes (OGG1, XRCC1, and XPD) were estimated by RT-PCR. The results indicated significantly higher levels of Pb in the exposed group as compared with the non-exposed group (p < 0.0001). Serum 8-OHdG concentrations were significantly higher (p < 0.0083), and all three DNA repair genes were significantly downregulated (fold change: OGG1, 0.188; XRCC1, 0.125; XPD, 0.133) in the Pb-exposed group as compared with the non-exposed. In conclusion, the study findings suggest that Pb exposure is associated with increased DNA damage and reduced DNA repair capacity, which may lead to serious health issues in occupationally Pb-exposed workers.

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.

Waterpipe smoke condensate influences epithelial to mesenchymal transition and interferes with the cytotoxic immune response in non-small cell lung cancer cell lines

Waterpipe tobacco smoking (WPS) continues to spread globally and presents serious health hazards. The aim of the present study was to investigate the effects of treatment with WPS condensate (WPSC) on lung cell proliferation and plasticity as well as tumor cell recognition and killing by natural killer (NK) cells using cytotoxicity assays. The results indicated that exposure of normal and cancer lung cell lines to WPSC resulted in a decrease in their in vitro growth in a dose-dependent manner and it induced tumor senescence. In addition, WPSC selectively caused DNA damage as revealed by an increase in γH2AX and 53BP1 in tumor lung cells. To gain further insight into the molecular mechanisms altered by WPSC, we conducted a global comprehensive transcriptome analysis of WPSC-treated tumor cells. Data analysis identified an expression profile of genes that best distinguished treated and non-treated cells involving several pathways. Of these pathways, we focused on those involved in epithelial to mesenchymal transition (EMT) and stemness. Results showed that WPSC induced an increase in SNAI2 expression associated with EMT, ACTA2 and SERPINE2 were involved in invasion and CD44 was associated with stemness. Furthermore, WPSC exposure increased the expression of inflammatory response genes including CASP1, IL1B, IL6 and CCL2. While immune synapse formation between NK and WPSC-treated lung cancer target cells was not affected, the capacity of NK cells to kill these target cells was reduced. The data reported in the present study are, to the best of our knowledge, the first in vitro demonstration of WPSC effects on lung cellular parameters providing evidence of its potential involvement in tumor physiology and development.

Buccal micronucleus cytome assay: Inter-laboratory scoring exercise and micronucleus and nuclear abnormalities frequencies in different populations from Brazil

The Buccal Micronucleus Cytome Assay (BMCyt) has become an important biomonitoring tool for assessing cytogenetic damage in many studied populations. Each laboratory applies protocols that vary according to the method of collecting and preparing samples. Besides, Brazil is a country of great territorial extensions that received immigrants from various parts of the world with different genetic backgrounds. Therefore, the present study aimed to evaluate the inter-laboratory variation in scoring the same set of slides using the more comprehensive scoring criteria, to standardize the BMCyt protocol, to observe the basal alterations in populations of different Brazilian regions and to compare it with other places around the world. Our results showed that a valuable number of laboratories participated, ten laboratories from different regions of the country, for the validation of the BMCyt in human biomonitoring studies, resulting in the 804 healthy individuals. This was possible because we observed: a range of measures needs to be considered, such as the baseline frequency of DNA damage and cell death in non-exposed individuals; age when grouped showed an influence on DNA damage, although when evaluated by group we did not see an influence; association between smoking habit and all endpoints of the BMCyt (except karyolytic cells) was evident; the basal MN frequency, in the majority of groups, follows those around the world; and the BMCyt was confirmed as a good health status biomarker. We emphasize the need for constant discussions on the parameters of cell death due to greater difficulty among the analyzers.

Protective Effects of Pinus halepensis Bark Extract and Nicotine on Cigarette Smoke-induced Oxidative Stress in Keratinocytes

BACKGROUND/AIM

Cigarette smoke (CS) is a major environmental health threat. The oxidative stress induced by CS on keratinocytes and the possible protective effect of nicotine, its receptor inhibitors, and Pinus halepensis bark extract in relation to known antioxidants were investigated.

MATERIALS AND METHODS

Primary mouse keratinocytes were exposed to cigarette smoke in the presence and absence of Pinus halepensis bark extract (1 μg/ml), rutin (50 μM) and ascorbic acid (250 μM), nicotine (1 μM) with or without mecamylamine (5 μM) and α-bungarotoxin (0.1 μM). Keratinocyte viability and oxidative stress were evaluated by MTT and fluorescence assays.

RESULTS

Pinus halepensis bark extract decreased the oxidative stress and increased the viability of keratinocytes, and moreover, these effects were more pronounced compared to the mixture of rutin and L-ascorbic acid. Nicotine significantly enhanced the viability potentiation of the beneficial effect induced by Pinus halepensis bark extract. Mecamylamine and α-bungarotoxin showed no specific effect.

CONCLUSION

Pinus halepensis bark extract in combination with nicotine may successfully reverse skin damage induced by cigarette smoke.

Dysregulation of Redox Status in Urinary Bladder Cancer Patients

The alteration of redox homeostasis constitutes an important etiological feature of common human malignancies. We investigated DNA damage, selenium (Se) levels and the expression of cytoprotective genes involved in (1) the KEAP1/NRF2/ARE pathway, (2) selenoprotein synthesis, and (3) DNA methylation and histone deacetylation as putative key players in redox status dysregulation in the blood of urinary bladder cancer (UBC) patients. The study involved 122 patients and 115 control individuals. The majority of patients presented Ta and T1 stages. UBC recurrence occurred within 0.13 to 29.02 months. DNA damage and oxidative DNA damage were significantly higher in the patients compared to the controls, while plasma Se levels were significantly reduced in the cases compared to the controls. Of the 25 investigated genes, elevated expression in the peripheral blood leukocytes in patients was observed for NRF2, GCLC, MMP9 and SEP15, while down-regulation was found for KEAP1, GSR, HMOX1, NQO1, OGG1, SEPW1, DNMT1, DNMT3A and SIRT1. After Bonferroni correction, an association was found with KEAP1, OGG1, SEPW1 and DNMT1. Early recurrence was associated with the down-regulation of PRDX1 and SRXN1 at the time of diagnosis. Peripheral redox status is significantly dysregulated in the blood of UBC patients. DNA strand breaks and PRDX1 and SRXN1 expression may provide significant predictors of UBC recurrence.

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.

Waterpipe (shisha, hookah) smoking, oxidative stress and hidden disease potential

Due to the abundant research on the harmful effects of cigarette smoking and the strict regulations enacted by many health authorities, many smokers are seeking for safer and more acceptable tobacco forms. Waterpipe (also known as shisha or hookah) use has increased dramatically during the past decade, mostly due to its improved taste, lack of regulations and social acceptability as a safer option than cigarettes. However, recent clinical and experimental studies indicate that waterpipe use is as, or even more, harmful than cigarettes. Although they differ in the method of consumption, waterpipe tobacco has similar deleterious constituents found in cigarettes but are generated at greater amounts. These constituents are known to induce oxidative stress and inflammation, the major underlying mechanisms of a wide array of chronic pathological conditions. We review the relationship between waterpipe tobacco use and oxidative stress and the disease potential of waterpipe use.

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Waterpipe tobacco smoking is growing in popularity globally, since it is thought to be a safer alternative to cigarette smoking.

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The amount of harmful substances produced from one waterpipe smoking session are greater than found in a standard cigarette.

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Waterpipe smoking can cause oxidative stress and inflammation, which precede and exacerbate multiple pathological conditions.

Immune modulation by chronic exposure to waterpipe smoke and immediate-early gene regulation in murine lungs

OBJECTIVE

We investigated the effects of chronic waterpipe (WP) smoke on pulmonary function and immune response in a murine model using a research-grade WP and the effects of acute exposure on the regulation of immediate-early genes (IEGs).

METHODS

WP smoke was generated using three WP smoke puffing regimens based on the Beirut regimen. WP smoke samples generated under these puffing regimens were quantified for nicotine concentration. Mice were chronically exposed for 6 months followed by assessment of pulmonary function and airway inflammation. Transcriptomic analysis using RNAseq was conducted after acute exposure to characterise the IEG response. These biomarkers were then compared with those generated after exposure to dry smoke (without water added to the WP bowl).

RESULTS

We determined that nicotine composition in WP smoke ranged from 0.4 to 2.5 mg per puffing session. The lung immune response was sensitive to the incremental severity of chronic exposure, with modest decreases in airway inflammatory cells and chemokine levels compared with air-exposed controls. Pulmonary function was unmodified by chronic WP exposure. Acute WP exposure was found to activate the immune response and identified known and novel IEG as potential biomarkers of WP exposure.

CONCLUSION

Chronic exposure to WP smoke leads to immune suppression without significant changes to pulmonary function. Transcriptomic analysis of the lung after acute exposure to WP smoke showed activation of the immune response and revealed IEGs that are common to WP and dry smoke, as well as pools of IEGs unique to each exposure, identifying potential biomarkers specific to WP exposure.

Testicular Toxicity of Water Pipe Smoke Exposure in Mice and the Effect of Treatment with Nootkatone Thereon

There is a worldwide increase in the popularity of water pipe (shisha) tobacco smoking including in Europe and North America. However, little is known about the effects of water pipe smoke (WPS) exposure on male reproductivity. We have recently demonstrated that WPS exposure in mice induces testicular toxicity including inflammation and oxidative stress. Nootkatone, a sesquiterpenoid found in grapefruit, has antioxidant and anti-inflammatory effects. However, the possible protective effect of nootkatone on WPS-induced testicular toxicity has not been reported before. Here, we tested the effects of treatment of mice with nootkatone on WPS-induced testicular toxicity. Mice were exposed to normal air or WPS (30 minutes/day, for 30 days). Nootkatone (90 mg/kg) was given orally to mice by gavage, 1 h before WPS or air exposure. Nootkatone treatment significantly ameliorated the WPS-induced increase in plasma levels of inhibin, uric acid, and lactate dehydrogenase activity. Nootkatone also significantly mitigated the decrease in testosterone, androgen-binding protein, and estradiol concentrations in the plasma induced by WPS. In testicular homogenates, WPS exposure caused a decrease in the total nitric oxide level and an increase in the proinflammatory cytokine interleukin-1β level and oxidative stress markers including malondialdehyde, cytochrome C, and 8-Oxo-2'-deoxyguanosine. All the latter effects were significantly alleviated by nootkatone treatment. Moreover, in testicular homogenate, nootkatone inhibited the expression of nuclear factor-kappaB induced by WPS. Likewise, histological examination of mouse testes showed that nootkatone treatment ameliorated the deterioration of spermatogenesis induced by WPS exposure. We conclude that nootkatone ameliorated the WPS-induced testicular inflammation and oxidative stress and hormonal and spermatogenesis alterations.