The antineoplastic drug Busulfan can lead to impaired antioxidant defense system. Silymarin as a natural herbal product has powerful antioxidant properties. In the present study, the effects of Busulfan and Silymarin on oxida-tive stress system were evaluated. For the study 48 rats were prepared and fed with special ration, then they we-re divided to 6 groups with 8 rats in each group: (C1): no drugs, (C2): 175 mg/kg/day Silymarin for 14 days as gavage, (C3): 20 mg/kg/day Busulfan for 14 days intra peritoneal, (T1): 20 mg/kg/day Busulfan for 14 days intraperitoneal and after 2 weeks 175 mg/kg/day Silymarin for 14 days as gavage, (T2): 20 mg/kg/day Busulfan for 14 days intrape-ritoneal and after 2 weeks 250 mg/kg/day Silymarin for 14 days as gavage, (T3): 20 mg/kg/day Busulfan for 14 days intraperitoneal and after 2 weeks 325 mg/kg/day Silymarin for 14 days as gavage. The amount of MDA, SOD and GPX in the different tissue extracts (liver, spleen, pancreas, testes, heart and kidneys) were measured. The results of this study showed that after Busulfan treatment, the activity of SOD and GPX in different tissues was signifi-cantly decreased. Silymarin in C1 could increase the activity of SOD and GPX compared to C3. In C3, the level of MDA in different tissues compared to other the groups was significantly increased. Silymarin in C1 could decrease the level of MDA compared to C3. It can be concluded that the use of Busulfan can induce oxidative stress and Silymarin had an antioxidant role along with decreasing the lipid peroxidation.
Keywords: Busulfan, Silymarin, Oxidative stress