Evaluation of cytogenic damage in the form of micronuclei in oral exfoliated buccal cells in tobacco users

Abstract

Background: Variety of substances such as tobacco, UV radiation, infrared rays, X-radiations, and chemicals on oral induction results in chromosomal aberrations and production of micronucleus (MN). Among them, tobacco-specific nitrosamines are potent mutagenic agents causing oral cancer.

Objective: The objective of the study is to compare the genotoxicity in buccal mucosal cells, i.e. the MN count of all groups and to find the incidence of micronucleated cells (MNCs) in accordance to duration and frequency of tobacco usage and timing of contact of tobacco in the oral mucosa.

Materials and methods: Individuals without any oral diseases were divided into 3 groups having 25 in each group: smoking, chewing, and control. Smears were made from buccal exfoliated cells and stained with DNA-specific Feulgen stain. Frequency on MNC per 500 cells was assessed with one-way ANOVA and Tukey HSD multiple comparisons test and mean rank with Kruskal-Wallis test.

Results: The mean micronucleus MN revealed that chewers had 8.00, smokers had 7.20 and controls had 0.4. The ANOVA test for mean frequency of micronucleated cell MNC revealed High significance (<0.001) for between groups comparison. The mean rank by Kruskal Wallis test revealed the MNC increases as the duration and frequency of habit increases. An increase in MNC in accordance to time of contact with buccal mucosa increases as the duration and time increases.

Conclusion: Estimation of MN serve as an indicator of genetic damage and points that tobacco in chewing form induce genotoxic effect. This is studied in an easily accessible tissue- buccal mucosa in a non invasive manner.

Keywords: Buccal exfoliated cells; Feulgen stain; genotoxicity; micronucleus; tobacco.