Assessment of Anticholinesterase Toxicity, Oxidative Stress and Antioxidant Status in Carbamate and Organophosphorus Pesticides-Exposed Agricultural Workers

Abstract

Among the numerous pesticides, anticholinesterase compounds are widely used. Their toxicity induced by cholinesterase inhibition at the synapses and neuromuscular junctions, leading to neurological disorders. Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) has been used as sensitive biomarkers for pesticides exposure. In the present study, AChE and BuChE levels were estimated in agricultural workers exposed to carbamate and organophosphorus pesticides with average 9.8±3.5 years relative to the controls. The toxic effects of pesticides may be attributed to induction of oxidative stress and alteration in antioxidant system. Our results showed significant decrease in AChE and BuChE levels with inhibition percentage of 39% and 61% respectively, in exposed workers than controls. Additionally, there was a significant increase in malondialdehyde (MDA) as an oxidative stress marker. Concerning antioxidant status, there was significant decrease in reduced glutathione (GSH) levels while there were significant increases in activity of glutathione dependent enzymes, glutathione peroxidase (GPx) and glutathione-S-transeferase (GST). On the other hands, there were significant decreases in enzymatic antioxidants, super oxide dismutase (SOD) and catalase. A negative correlation was found between BuChE activity and MDA levels. So, it was concluded that evaluation of BuChE inhibition may be sensitive tool for assessing the risk of oxidative stress induced after occupational pesticides exposure.