Assessment of cytogenic damage in the form of micronuclei in oral epithelial cells in patients using smokeless and smoked form of tobacco and non-tobacco users and its relevance for oral cancer

Abstract

The use of smokeless and smoked tobacco are associated with cytotoxic and genotoxic effects. SLT seems to cause more damaging effects than the smoked form.

Comparative Study of Micronuclei Count in Patients with Different Tobacco-related Habits using Exfoliated Buccal Epithelial Cells: A Tool for Assessment of Genotoxicity

“…The results showed that the mean number of micronuclei in group III, i.e., subjects with combined habit (22.44 ± 9.84) was higher as compared with smokeless tobacco users (18.28 ± 10.00), tobacco smokers (11.38 ± 6.38), and control group (4.86 ± 2.49). Similar type of findings has been reported by Patel et al, 19 Palaskar and Jindal, 20 Bansal et al, 21 Motgi et al, 22 and Sangle et al 23 According to our results, the extent of genotoxic damage is more in smokeless tobacco users as compared with smoking tobacco. This may be explained by the fact that during chewing, mucosa is in direct contact with tobacco for a longer period of time as compared with smoking which may result in prolonged absorption of nitrosamines, and hence, considerably more nuclear and DNA damage.…”

“…25 Smokers absorb nicotine mainly through the pulmonary vasculature while smokeless tobacco users absorb nicotine through buccal mucosa and gastrointestinal mucosa. 22 On the contrary, Pradeep et al 7 reported higher mean micronuclei count in smoking habit followed by smoking with betel quid, smokeless tobacco, and control. This finding has been supported by the fact that since betel leaf is a rich source of antioxidants, it may nullify the genotoxic effects of tobacco.…”

“…24 In India, individual farmers and companies process smokeless tobacco with varied rate of fermentation and curing, which increases the production of tobacco-specific nitrosamines. 22 Moreover, smokeless tobacco is generally used in combination with betel leaf, areca nut, or slaked lime, all of which increases the toxicity of tobacco. 25 Smokers absorb nicotine mainly through the pulmonary vasculature while smokeless tobacco users absorb nicotine through buccal mucosa and gastrointestinal mucosa.…”

Cytogenetic Biomonitoring in Buccal Mucosa Cells from Young Smokers

“…Kayal et al [11] investigated micronuclei in buccal mucosa cells of persons who chewed indigenous products (areca nut, mava, tamol, tobacco with lime, dry snuff, or mashery), but not tobacco cigarettes. Motgi et al [12] have demonstrated that total numbers of micronucleated cells were significantly lower in non-tobacco users when compared with tobacco users, but such data were obtained by using non-specific DNA stains (Papanicolaou stain). Others have yet revealed a lack of statistical significance for micronucleus frequency between smokers and non-smokers in patients previously submitted to dental X-ray [13,14].…”

Tobacco Use and Cancer Risk in the Agricultural Health Study

“…reported a significant 1.4 relative risk pooled from 40 studies (37). Consistent with these epidemiologic finding, laboratory studies have suggested that TSNAs, in particular N -nitrosonornicotine (NNN), are responsible for cytogenic damage in oral epithelial cells (22, 39, 40). …”