Effects of chlorpyrifos, emamectin benzoate and abamectin pesticides on antioxidant systems and lipid peroxidation in liver tissue of oreochromis niloticus

In the present study, it was investigated effects of organophosphate insecticide chlorpyrifos (CPF) and avermectin insecticides abamectin (ABM) and emamectin benzoate (EB) on antioxidant parameters and lipid peroxidation in liver chosen as target organ in Oreochromis niloticus. For this purpose fish were exposed to 5.0 and 10.0 ppb of CPF, ABM and EB for 48 and 96 hours and activities of catalase (CAT), superoxide dismutase (SOD) and glutathione reductase and levels of glutathione (GSH) and malondialdehyde (MDA) were determined. Significant alterations in all analyzed biochemical parameters were observed due to pesticide, medium concentration and exposure period. In fish exposed to CPF, CAT activity increased after 48-h whereas it decreased after 96-h. In higher concentrations, it was observed CAT activity declined in 48- and 96-h ABM-exposed fish, whereas it elevated in 48-h EB-exposed ones. SOD activity showed a decrease in all the tested pesticide exposures after both periods. Also CPF, ABM and EB caused a decline in GR activity after 96-h, especially in their higher concentrations. In CPF-exposed fish, although GSH level elevated after 48-h, it decreased at the end of the exposure period. In 96-h ABM- and EB-exposed fish, GSH level declined in their higher concentrations. It was observed an increase in MDA levels of fish exposed to higher concentrations of CPF, ABM and EB for 96 h. In conclusion, it was determined the effects of pesticides on analyzed all parameters were as CPF>ABM>EB and these pesticides caused oxidative stress in the liver of O. niloticus.