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

Chlorpyrifos-ethyl (CPF) is an organophosphate insecticide mostcommonly used worldwide. Chlorpyrifos was evaluated for its effects onhepatic content of cytochrome b5, P450, NADPH cytochrome-C reductase,amidopyrine-N-demethylase, aniline 4-hydroxylase activities,thiobarbituric acid reactive substance (TBARS), enzymes concerning liverdamage, and the protective effects of garlic in albino rats. Pretreatment ofrats with repeated doses of garlic prior to administration of CPF decreasedthe hepatic content of cytochrome b5, the activities of NADPHcytochrome-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, garlicaugmented 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, TBAR