Chlorpyrifos induced modulation in the activities of hepatic drug metabolizing enzymes of rats: Role of garlic

Chlorpyrifos-ethyl (CPF) is an organophosphate insecticide most commonly used worldwide. Chlorpyrifos was evaluated for its effects on hepatic content of cytochrome b5, P450, NADPH cytochrome-C reductase, amidopyrine-N-demethylase, aniline 4-hydroxylase activities, thiobarbituric acid reactive substance (TBARS), enzymes concerning liver damage, and the protective effects of garlic in albino rats. Pretreatment of rats with repeated doses of garlic prior to administration of CPF decreased the hepatic content of cytochrome b5, the activities of NADPH cytochrome-C-reductase, amidopyrine-N-demethylase, aniline-4- hydroxylase and TBARS levels. The activity of glutathione-S-transferase (GST) was significantly inhibited after CPF administration, while, garlic augmented the reduction of GST activity affected by CPF. Liver AST, ALT, ALP and ACP were increased due to CPF administration to rats. Meanwhile, garlic afforded a significant protection against CPF intoxication. It is concluded that repeated doses of garlic may reduce the toxic effects exerted by CPF upon the liver through inhibition of cytochrome P450 system that activates CPF into its active metabolite. Also, garlic reduces lipid peroxidation and restores the liver damage caused by CPF. Keywords : Chlorpyrifos, Cytochrome P450 enzymes, Garlic, TBARS