Organophosphorus compounds cause oxidative stress and lead to alterations in antioxidant status in organisms. In this study, the effects of subchronic exposure to malathion and the protective effects of boron (B) were evaluated in 48 Wistar rats, which were divided equally into six groups. For 28 d, the control group received a normal diet and tap water, the corn oil group received a normal diet and 0.5 mL of corn oil by gastric gavage and the malathion group received a normal diet and malathion (100 mg/kg/d) by gastric gavage. During the same period, each of the three other groups received a different dosage of B (5, 10 and 20 mg/kg/d, respectively) and malathion (100 mg/kg/d) by gastric gavage. Malathion administration during the period increased malondialdehyde, nitric oxide and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, as well as markers of liver function, yet decreased acetylcholinesterase, reduced glutathione, superoxide dismutase, and catalase activities in blood, liver, kidney and brain tissues. Administration of B in a dose-dependent manner also reversed malathion-induced oxidative stress, lipid peroxidation (LPO) and antioxidant enzyme activity. Moreover, B exhibited protective action against malathion-induced histopathological changes in liver, kidney and brain tissues. These results demonstrate that, if used in a dose-dependent manner, B decreases malathion-induced oxidative stress, enhances the antioxidant defense mechanism and regenerates tissues in rats.
Keywords: Acetylcholinesterase; Malathion; boron; oxidative stress; rat.