An, In Vitro, Study of some Pesticides on the Activity of Human Serum Paraoxonase (PON1)

Paraoxonase-1 (PON1) is a high density lipoprotein (HDL)-associated enzyme capable of hydrolyzing diverse substrates from organophosphate (OP) toxins to oxidized phospholipids. In this study, the effects of dichlorvos, parathion-methyl, dimethoate, chlorpyrifos methyl, chlorpyrifos ethyl, acetamiprid, mancozeb, lufenuron and trifluralin which are pesticides, were investigated on human serum paraoxonase as in vitro. While trifluralin, mancozeb and methyl parathion enhanced the PON activity, lufenuron, dimetoate and chlorpyrifos methyl and chlorpyrifos ethyl firstly activated and then they inhibited in the different range of enzyme activity. It was determined that acetamidine and dichlorvos were inhibited and the CI50 values of the chemicals caused inhibition were calculated by means of activity percentage-[I] diagrams. The values of CI50 were 38,19 mM and 13,49 mM for PON1 respectively. Changes of PON enzyme’s kinetic parameters were most important during pesticide metabolism, because pesticides were risk for human health.