Inhibition of 1,2-dimethylhydrazine induced colon genotoxicity in rats by the administration of probiotic curd

Epidemiologic and experimental studies suggest that the probiotic organisms are effective in preventing colon carcinogenesis, which is the major cause of mortality and morbidity in western countries. Keeping this in view, a curd (a common Indian fermented milk product) was prepared by the addition of probiotic cultures Lactobacillus acidophilus, Lactobacillus casei and curd culture Lactococcus lactis biovar. diacetylactis. In present study, we have evaluated the anti tumor effect of probiotic curd by monitoring the DNA damage through comet assay. The rats were allocated to four groups, first group was DMH control group, second group was probiotic curd group in which probiotic curd was given along with DMH (1,2-dimethylhydrazine) injection, third group was normal curd group in which normal curd was given along with DMH injection and fourth group was normal control group. Animals received subcutaneous injection of DMH dissolved in normal saline at a dose rate of 20 mg/kg body weight, once weekly for 15 weeks. The rats were dissected at 40th week of experiment and comet assay was done in colonic cells to assess the DNA damage. A significant reduction in DNA damage (54.7%) was observed in probiotic curd group as compared to DMH control group (88.1%). The probiotic curd was effective to significantly reduce the L:W ratio in comparison to DMH control group and normal curd. The results of present study show the protective effects of probiotic curd against DMH induced genotoxicity in colonic cells.