Study of Diazinon Effect on Antioxidant Enzymes and Lipid Peroxidation in Rat's Brain

Organophosphates (OPs) are capable to produce free radicals and induce disturbance in body antioxidant system. Diazinon is one of the most widely used OPs in agriculture. The aim of this study was to investigate the effects of diazinon on oxidant-antioxidant system in rat's brain tissue. In this experimental study, male Wistar rats were randomly divided into four groups as follows: control group(corn oil as diazinon solvent) and three case groups receiving diazinon at different doses (30, 50 and 100 mg/kg) via intraperitoneal injection. 24 hours after injection, the animals were anesthetized and their brain tissues were removed. After brain tissue hemogenation, superoxide dismutase (SOD), catalase (CAT), lactate dehydrogenase (LDH) and glutathione S-transferase (GST) activities as well as glutathione (GSH) and malondialdehyde (MDA) levels were determined by biochemical methods.�The data were statistically analyzed using analysis of variance (ANOVA) followed by post hoc analysis using Tukey test. Diazinon increased SOD, LDH and GST activities at doses of 50 and 100 mg/kg compared with the control group but decreased GSH level. There were no significant changes observed in brain CAT activity. Also, MDA concentration was significantly increased at 100 mg/kg dose in comparison with the control group. The results suggest that diazinon probably causes free radical production. Enhanced activity of antioxidant enzymes and depleted GSH content are indicative of oxidative tissue injury and the increased MDA level is indicative of the damage that occurs in the membranes of brain tissues as a result of free radical generation.