Evaluation of cytotoxic effect of smokeless tobacco extract using allium cepa abberation assay

Smokeless tobacco products are not burnt when used. There is an increasing interest and controversy within the public health community about smokeless tobacco. Smokeless tobacco especially the chewing tobacco commonly known as gutka was studied for its genotoxic effect using Allium cepa chromosome aberration assay. Gutka is an extremely popular herbal concoction sold throughout subcontinent. Aqueous extract of the selected smokeless tobacco was prepared, EC50 value for Allium root growth inhibition was determined (1000ppm) and accordingly different concentration in ppm (100, 300,500,1000,1500,2000, 2500, & 3000 ppm) were selected to study the effect in response to time (24 hrs and 48 hrs) on the mitotic activity of the growing root tips. The mitotic index was the least (2.04) at the highest concentration (3000 ppm) at 48 hrs treatment of gutka than 33.20 (24 hrs) and 36.37 (48 hrs) in the control set using normal water. The genotoxicity of gutka was measured using the frequency of chromosomal aberrations. The high frequency of sticky chromosomes, laggard and multipolarity indicated that smokeless tobacco product like the gutka too can cause abnormal DNA condensation, abnormal chromosome coiling and inactivation of the spindles, having an eugenic potential. The Cytotoxic threshold concentration was estimated to be 500 ppm though no lethal effects were observed.