Oxidative stress in testes of rats exposed to n-butylparaben.

This study was aimed at determining if oxidative stress imbalance in testes of rats occurs after n-butylparaben (n-ButP) exposure. Young male Sprague-Dawley rats were subcutaneously treated with n-ButP during one spermatogenic cycle (57 days) at 0 (control-oil), 150, 300 and 600 mg/kg/d with peanut oil as vehicle. A non-vehicle control group was also included. Antioxidant enzyme activities (superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase) and levels of reduced and oxidized glutathione were measured in testes. Lipid peroxidation and H2O2 concentrations were also assessed. Results showed an increase of oxidative stress in oil-treated groups, excepting 600 mg/kg/d, suggesting oxidative stress due to peanut oil. A possible antioxidant effect due to n-ButP and its metabolites was suggested at 600 mg/kg/d, the only group not showing oxidative stress. An increase of calcium concentration in testes was also observed. On the other hand, a physiologically-based pharmacokinetic (PBPK) model was developed and the concentrations of n-ButP and its metabolites were simulated in plasma and testes. The peak concentration (Cmax) in testes was found slightly higher than that in plasma. The current results indicate that peanut oil can cause oxidative stress while high doses of n-ButP can act as antioxidant agent in testes.