Antioxidant effects of Dendropanax morbifera Leveille extract in the hippocampus of mercury-exposed rats

Background: Dendropanax morbifera Leveille has been employed for the treatment of infectious diseases using folk medicine. In this study, we evaluated the antioxidant effects of a leaf extract of Dendropanax morbifera Leveille in the hippocampus of mercury-exposed rats. Methods: Seven-week-old Sprague-Dawley rats received a daily intraperitoneal injection of 5 mu g/kg dimethylmercury and/or oral Dendropanax morbifera Leveille leaf extract (100 mg/kg) for 4 weeks. Animals were sacrificed 2 h after the last dimethylmercury and/or leaf extract treatment. Mercury levels were measured in homogenates of hippocampal tissue, a brain region that is vulnerable to mercury toxicity. In addition, we measured reactive oxygen species production, lipid peroxidation levels, and antioxidant levels in these hippocampal homogenates. Results: Treatment with Dendropanax morbifera Leveille leaf extract significantly reduced mercury levels in hippocampal homogenates and attenuated the dimethylmercury-induced increase in the production of reactive oxygen species and formation of malondialdehyde. In addition, this leaf extract treatment significantly reversed the dimethylmercury-induced reduction in the hippocampal activities of Cu, Zn-superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase. Conclusion: These results suggest that a leaf extract of Dendropanax morbifera Leveille had strong antioxidant effects in the hippocampus of mercury-exposed rats.