Effect of Aflatoxin B1 on Histopathology and Oxidative Stress Biomarkers in Testis of Rats with Special References to Gene Expression of Antioxidant Enzymes

The stimulation of oxidative stress and lipid peroxidation of liver tissues by AFB1 has been extensively investigated. However, the effect of AFB1 on antioxidant enzyme activities and gene expression in testis has not been completely elucidated. The current study investigated the histopathological picture and activities in addition to gene expression of antioxidant enzymes in testis of rats intoxicated with AFB1. Twenty rats were divided into two equal groups. Rats in the first group served as control whereas, rats in the second group received single i.p. dose of AFB1 (3 mg kg(-1) b.wt.). Testicular damage and oxidative stress were evident in AFB1-intoxicated rats as indicated by a significant increase in thiobarbituric acid reactive substances (TBARS), reduction of reduced glutathione (GSH) concentration, reduction in the activities of antioxidant enzymes namely catalase (CAT), total superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-s-transferase (GST) and down-regulation of gene expression of these antioxidant enzymes compare to control. Testicular sections of rats intoxicated with AFB1 showed mild testicular degeneration of some seminiferous tubules manifested by reduced numbers of spermatogenic cells and associated with buckling of the seminiferous basement membranes. In conclusion, testicular injury, high lipid peroxidation, low GSH concentration and inactivation and down-regulation of gene expression of antioxidant enzymes are involved during AFB1 toxicity in rats.