ABSTRACT
Exposure to paraoxon (POX) and leptin (LP) could cause an imbalance between oxidants and antioxidants in an organism, which can be prevented by introduction of exogenous antioxidants such as N-acetylcysteine (NAC). The aim of this study was to evaluate synergic or additive effects of administration of exogenous LP plus POX on the antioxidant status, as well as the prophylactic and therapeutic roles of NAC in various rat tissues. Fifty-four male Wistar rats were divided into nine groups treated with different compounds: Control (no treatment), POX (0.7 mg/kg), NAC (160 mg/kg), LP (1 mg/kg), POX+LP, NAC-POX, POX-NAC, NAC-POX+LP, and POX+LP-NAC. In the last five groups, only the order of administered compounds differed. After 24 h, plasma and tissues were sampled and examined. The results showed that administration of POX plus LP significantly increased biochemical indices in plasma and antioxidant enzymes activities and decreased glutathione content in the liver, erythrocytes, brain, kidney, and heart. In addition, cholinesterase and paraoxonase 1 activities in the POX+LP-treated group were decreased and malondialdehyde level was increased in the liver, erythrocytes, and brain. However, administration of NAC rectified induced changes although not to the same extent. Our study suggests that POX or LP administration engage the oxidative stress system per se; however, their combination did not produce significantly greater effects. Moreover, both prophylactic and therapeutic treatments of rats with NAC supported the antioxidant defense against oxidative damage in tissues, most probably through both its free radical scavenging ability and maintaining intracellular GSH levels. It can therefore be suggested that NAC has particularly protective effects against POX or/and LP toxicity.
