Rutin imparts attenuation of methyl parathion-induced base-pair substitution

Pesticides plays an important role in the modern agricultural system. Methyl parathion (MP), an organophosphorus insecticide, reported to impose various adverse effects on non-target organisms, including mutagenicity. In the present study, the possible antimutagenic activity of rutin, a flavonoid with potential antioxidant activity, was assessed against MP-induced mutagenicity by employing the Ames test. Salmonella typhimurium -TA 100 was used as the test strain representing the base-pair substitution. A concentration-response toxicity was performed by selecting 0.1, 0.5 and 1.0mg/ml of MP. The protective effect of rutin was assessed at 5, 10 and 20mg/ml against 0.5mg/ml of MP-induced mutagenicity with and without metabolic activation. The results indicated that MP induced concentration-dependent mutagenicity up to 0.5mg/mL (p<0.001). However, growth inhibition was observed in the highest concentration of MP, both in the presence and absence of S9 fraction, indicating the lethality. Rutin induced a concentration-dependent decrease in the frequency of revertant colonies at a significant level up to 1.0mg/ml (p<0.05 and p<0.01) compared with that of MP-treated strains in the presence of S9 fraction. Thus, rutin has the potency to minimize the base-pair substitution induced by MP after metabolic activation, with a threshold limit.