Antigenotoxic effect of genistein against 7,12-dimethylbenz[a]anthracene induced genotoxicity in bone marrow cells of female Wistar rats.

Carcinogen induced mutation in somatic cells leads to genetic instability, which is considered as an important facet of carcinogenesis. Agents that inhibit DNA adduct formation, stimulate DNA repair mechanisms, and possess antioxidant functions are considered as antigenotoxic agents. Genistein, the major isoflavone of soy products, protects animals against experimentally induced mammary and prostate cancers. 7,12-Dimethylbenz[a]anthracene (DMBA), a potent site-specific carcinogen, induce mutations in DNA through its active metabolite, dihydrodiol epoxide, what is a crucial step in cancer initiation. The antigenotoxic effect of genistein against DMBA-induced genotoxicity has been investigated in the present study by analyzing the frequency of micronucleated polychromatic erythrocytes (MnPCEs) and chromosomal aberrations as cytogenetic end-points. The status of lipid peroxidation, antioxidants and detoxication agents were used as biochemical end-points to assess the antigenotoxic effect of genistein. Elevated MnPCEs frequency, marked chromosomal aberrations and enhanced status of lipid peroxidation, antioxidants and detoxication agents were observed in DMBA-treated animals. Oral pretreatment of genistein (20 mg/kg b.w.) for 5 days to DMBA-treated animals significantly reduced the frequency of micronucleus formation and chromosomal abnormalities as well as reversed the status of biochemical variables. Our results suggest that genistein has potent antigenotoxic effect against DMBA-induced genotoxicity.