Effects of Organophosphorus and Pyrethroid Pesticides on Antioxidant Enzymes and Reactivation Effects of Pralidoxime: In vitro Studies

Abstract

The present study was aimed to assess the inhibition effects of organophosphate pesticides, malathionR, dichlorvosR; pyrethroid pesticides, deltamethrinR, λ-cyhalothrinR on antioxidantenzymes and reactivation ability of pralidoxime against pesticide inhibited-antioxidant enzymes. Oximes were reported by reactivation ability against organophosphate inhibited- acetylcholinesterase and we focused to investigate the reactivation effect of pralidoxime against organophosphate inhibited–antioxidant enzymes. IC50 values were determined by means of activity percentage diagrams. The concentrations of deltamethrinR, malathionR,dichlorvosR, λ-cyhalothrinR that inhibited 50% of catalase were 5.2 μM, 158 μM, 133 μM,320 μM, respectively, inhibited 50% of superoxide dismutase were 62 μM, 240 μM, 328 μM, 2320 μM, respectively and inhibited 50% of glutathione peroxidase were 0.7 μM, 1198 μM, 1638 μM, 98 μM, respectively. All pesticide doses showed inhibition effect on antioxidant enzymes. DeltamethrinR was found to be a more potent inhibitor for the antioxidant enzymesfollowed by the rest of pesticides used in this study. Reactivation effect of pralidoxime was determined for organophosphate inhibited-enzymes. Reactivation results showed that only catalase is reactivated by pralidoxime against dichlorvosR and malathionR. Under the exposureof 50-800 μM malathionR concentrations, catalase activity % was calculated as 72-11%,respectively. After inhibited catalase by malathionR incubated with 1 mM and 10 mMpralidoxime, catalase activity % was calculated as 92-31% and 98-39%, respectively. Under the exposure of 100-1500 μM dichlorvosR concentrations, catalase activity % was calculatedas 50-6%, respectively. After inhibited catalase by dichlorvosR incubated with 1 mM and 10mM pralidoxime, catalase activity % was calculated as 95-30% and 93-28%, respectively. When the results are examined, it is seen that increasing the pralidoxime concentration does not significantly affect the reactivation percentage of the catalase enzyme.