Influence of pesticides on the pH regulatory enzyme, carbonic anhydrase, from European Seabass liver and bovine erythrocytes

The objective of this study was to assess the inhibitory effects of six commonly used pesticides, cyhalothrin, cypermethrin, dichlorvos, methamidophos, chlorpyrifos and methylparathion, on the pH regulatory enzyme carbonic anhydrase (CA) of Dicentrarchus labrax (European Seabass) liver (dCA) and bovine erythrocytes (bCA). Results of the study showed that the pesticides displayed quite variable inhibition profiles with KI values ranging from 0.376 to 26.164 μM against dCA, and from 1.174 to 53.281 μM against bCA. Methylparathion was the most effective inhibitor for both enzymes. Overall data show that all of the tested pesticides inhibit both dCA and bCA at low concentrations indicating that indiscriminate use of these pesticides might cause disruption of acid base regulation resulting in animal deaths. Our results also point out that susceptibility to these pesticides varies among CAs from different organisms.

► CA has been purified from European Seabass liver and bovine erythrocytes with high yield by simple methods.
► Cyhalothrin, cypermethrin, dichlorvos, methamidophos, chlorpyrifos and methylparathion strongly inhibited both CA enzymes in vitro.
► Methylparathion was the most effective inhibitor for both enzymes.
► Susceptibility to these pesticides varies among CAs from different organisms.