The Effect of Sulfur Mustard on Antioxidant System Enzymes in Different Tissues of Rat

Sulfur mustard (SM) is a lipophilic blistering agent that alkylates a wide range of cellular macromolecules including DNA, RNA and protein, leading to cell death in different tissues. In spite of numerous studies, the mechanism of action of SM is still unknown. The aim of this study was to investigate the effect of SM on antioxidant system enzymes in different tissues of rats. Male Wistar rats were randomly divided into seven groups as followed: Group 1 control that received DMSO (dimethyl sulfoxide used as solvent), group 2-7 as experimental groups that received SM (1-80mg/kg) by intraperitoneal injection only once. 24 hours after injection, animals were anesthetized and kidney, lung and heart tissues were quickly removed. Blood was also collected by cardiac puncture, plasma and erythrocytes were obtained. Then, the enzyme activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) in different tissues were determined by biochemical methods. The data were analyzed using one way variance analysis followed by post hoc analysis using Tukey test. The significance level was considered as p<0.05. At doses lower than 20mg/kg SM, the increased SOD and GST activities in lung and GST activity in heart were observed, while antioxidant enzymes activities in different tissues were decreased at higher doses of SM. SM affects the antioxidant defense system in a dose-dependent manner. At lower doses than 20mg/kg, the enhanced activity of antioxidant enzymes may be a compensatory response to scavenge reactive oxygen species and the decreased activity of antioxidant enzymes at higher doses of SM is indicative the induction of oxidative stress and cell death in tissues.