Measurement of oxidative stress parameters in the hippocampus after 2 months of GBH exposure (25, 50, 75 and 100 mg/kg). (A) the nitric oxide (NO) levels, (B) Changes in catalase activity, (C) Determination of the lipid peroxidation levels. Results are represented as mean ± SEM. The significance level is 0.05. *p < 0.05, **p < 0.01, ***p < 0.001.