Evaluating Oxidative Stress Factors Induced by Chlorpyrifos Poisoning in Plasma of Wistar Rat

Chlorpyrifos (CPF) is a broad-spectrum organophosphorus insecticide that has been used abundantly over the globe during the past 40 years. Chemical pesticides may induce oxidative stress via generating free radicals and altering antioxidant levels of the free radical scavenging enzyme activity. Therefore، this study aimed to evaluate the toxicity of Chlorpyrifos-induced oxidative stress in the plasma samples of Wistar rat. Twenty-four male Wistar rats were selected randomly which were assigned to 2 equal groups، e. g. control and test. The control group received corn oil as the solvent، and the experimental group received 16. 5mg/kg/day of CPF (4mg/ml) orally via a stomach tube for four weeks. Plasma samples were taken on 1st، 7th، 14th، 21st، and 28th days، at a specific time. Catalase (CAT)، superoxide dismutase (SOD) activities and also levels of malondialdehyde (MDA) and glutathione (GSH) were determined. The oral administration of CPF could induce symptoms such as tremors، hair erection، weakness، diarrhea and asthma on Day 7 and onward. The data analysis of plasma samples showed significant (P<0. 001) decrease in the levels of glutathione and CAT enzymatic activity and a significant increase in SOD enzymatic activity and the MDA level. CPF could induce oxidative stress probably via production of free radicals as was evident by reduction of GSH level and CAT activity accompanied by increase in the activity of SOD and enhancement in the level of MDA in plasma samples. This necessitates the application of antioxidants when having exposure with OP pesticides.