Genotoxic effects of tobacco use in residents of hilly areas and foot hills of Western Ghats, Southern India

Abstract

Smoking and smokeless tobacco consumption is a significant risk factor that provokes genetic alterations. The present investigation was to evaluate the biomarkers of genotoxicity including micronucleus (MN), chromosome aberrations (CA) and DNA strand breaks among tobacco consumers and control individuals residing in hilly areas of Western Ghats, Tamilnadu, South India. This study included 268 tobacco consumers with equal number of controls. The tobacco consumers were divided into Group I (<10 years of tobacco consumption with an age range from 15 to 35 years) and group II (>10 years consumption above 35 years of age). Chromosome aberration (CA) and comet assay were performed using blood and micronucleus assay from exfoliated buccal epithelial cells obtained from tobacco consumers and controls. Elevated levels of CA were found in group II (Chromatid type: 2.39 ± 1.13 and chromosome type: 1.44 ± 1.24) exposed subjects, high micronucleus and DNA damage (TL:4.48 ± 1.24 and TM:3.40 ± 1.58) levels were significantly (p < 0.05) observed in both smoking and smokeless tobacco consumers when comparison with group I and controls. This study also observed a lack of awareness among the tobacco consumers about the harmful health effects of tobacco. Tobacco consumption contributes to the significant alteration in genetic materials. In addition, a high rate of spontaneous abortion was also seen in the studied population.

Early Diagnosis of Oral Mucosal Alterations in Smokers and E-Cigarette Users Based on Micronuclei Count: A Cross-Sectional Study among Dental Students

“…A possible explanation for this can be the young age of the participants, the relative decreased number of package-years in the group of conventional smokers and the fact that exfoliative cytology can sometimes underestimate the MN count due to the time needed for the migration of cells from basal to superficial layers of the oral epithelium. We found that more cells showing MN were present in specimens from smokers and e-cigarettes users compared with nonsmokers, similar to data reported by other studies [29,43]. Furthermore, a systematic review of clinical studies published in 2018 found a higher frequency of MN in exfoliated cells of smokers compared to non-smokers and concluded that this is associated with cytotoxic and genotoxic effects [44].…”

Evaluation of Micronuclei and Cytomorphometric Changes in Patients with Different Tobacco Related Habits Using Exfoliated Buccal Cells

“…We also found that frequency of cells showing micronuclei was significantly increased in combined tobacco users when compared with other groups. Similar findings were observed by (Upadhyay et al, 2019;Chandirasekar et al, 2019). The micronuclei related genotoxic alterations in the cells may be due to the possibility that the buccal mucosa cells get direct exposure to the carcinogenic amines present in the tobacco (Proia et al, 2006).…”

Environmental Tobacco Smoke in Occupational Settings: Effect and Susceptibility Biomarkers in Workers From Lisbon Restaurants and Bars

“…The effect of smoking on DNA damage has been thoroughly studied, mainly as a confounding factor in biomonitoring studies addressing exposure to other compounds (68,69). Despite that, discrepant results have been reported in the literature, either describing a lack of association between smoking and DNA damage induction (the majority of studies), as reviewed elsewhere (68)(69)(70) or an increased DNA damage in smokers comparatively to non-smokers (37,38,(71)(72)(73)(74). Very few studies have been published in respect to the effect of ETS exposure on this biomarker and contradictory results have been reported.…”