Influence of Sublethal Chlorpyrifos Exposure on Oxidative Stress and Acetylcholinesterase Activity in Common Carp (Cyprinus Carpio)

Abstract

The commonly used pesticides in agriculture cause enzyme inactivation and DNA damage via reacting with macromolecules and may also initiate peroxidation of poly-unsaturated fatty acids (PUFA) by generating of the reactive oxygen species (ROS), as a consequence they can lead to the oxidative stress. The objective of this study was to determine the oxidative and neurotoxic potential of sublethal chlorpyrifos in the brain tissue of Cyprinus carpio (C. carpio) for a period of 96 and 240 hours, respectively. Therefore, the levels of malondialdehyde (MDA), glutathione (GSH), advanced oxidation protein products (AOPP), protein carbonyl, and 8-hydroxydeoxyguanosine (8-OHdG) levels and activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and acetylcholinesterase (AChE) were investigated in order to determine the neurotoxic effect in brain tissue of C. carpio exposed to chlorpyrifos. Administration of chlorpyrifos at 0.26 and 0.52 mg/L concentrations caused a significant increase in MDA levels at the 240th hour (p<0.05), the latter concentration increased the GSH level but decreased SOD, GSH-Px, and CAT activities at the 240th hour (p<0.05). Only 0.52 mg/L of chlorpyrifos administration increased protein carbonyl but not AOPP levels at the 240th hour (p<0.05). 0.26 and 0.52 mg/L of chlorpyrifos concentrations caused a significant increase 8-OHdG levels at the 96th and the 240th hours (p<0.05). Chlorpyrifos statistically significantly reduced the AChE levels in both periods and at all administered concentrations (p<0.05). We observed an enhanced oxidative stress and inhibited AChE activity in the brain tissue of C. carpio after exposure to chlorpyrifos. These findings show that sublethal concentration of chloropyrifos leads to significant toxicity in the brain tissues of C. carpio.