Assessment of genotoxicity of nicotine employing in vitro mammalian test system.

Genotoxicity of nicotine was evaluated employing Chinese hamster ovary (CHO) cells. Two cytogenetic endpoints, viz. frequency of sister chromatid exchange (SCE) and chromosome aberration (CA) were considered. Nicotine was found to induce CA and SCE frequency in a dose and duration dependent manner. Statistically significant elevations in CA frequency were observed only with higher concentrations of nicotine, whereas, SCE frequencies were increased significantly by all the doses utilized. It was genotoxic at the concentration, comparable to the saliva levels of nicotine achieved during tobacco chewing. The results obtained by continuous and pulse treatments with nicotine explain the harmful effects of chronic tobacco consumption.