Evaluation of cytotoxic and genotoxic effects of cured and green raw tobacco leaves extracts using ‘ Allium cepa assay’

Globally cultivated tobacco plant is economically very significant, but it is one of the leading causes of preventable death. The cytotoxicity of cured tobacco leaves extract is well documented, while the effect of green tobacco leaves extract is ignored, although evidence is available about occupational hazard, that is, green tobacco sickness through its intradermal nicotine absorption. Both extracts showed cytotoxic, clastogenic and genotoxic effects in A. cepa root tip cells when the germinated seeds were exposed with green and cured leaves extract for different time interval (15, 30, 45, and 60 minutes) at a fixed concentration of 10% (w/v). The mitotic indices decreased significantly with increasing exposure time in both extracts. The average mitotic index of five replica of control was 22.64%, while it is 7.8% and 15.2% for cured and green extracts, respectively, at 60 minutes exposure time. The chromosomal aberrations like stickiness, bridges were observed in both extracts. Micronuclei and nuclear budding were more prevalent in the cured extract but were also detected in the green extract at lower frequency. Therefore, along with spreading awareness about consumption of smokeless tobacco, occupational safety measures for green leaves are also required.