Mailuoning suppresses H2O2-induced cortical neuronal injury and correlates with increased catalase activity and inhibited oxidative stress function

BACKGROUND: Mailuoning, a Chinese herb, has been widely used in China to treat acute ischemic stroke, and the major component exhibits anti-oxidative effects. However, the precise anti-oxidation pathway remains uncertain. OBJECTIVE: To validate the protective effects of Mailuoning on H2O2-induced primary cortical neuron injury in embryonic mice. DESIGN, TIME AND SETTING: Comparative observation and in vitro experiments were performed at the Jiangsu Key Laboratory for Molecular Medicine from January 2008 to September 2009. MATERIALS: Mailuoning (Nanjing Jinling Medical Company, China), reactive oxygen species (ROS) kit (Beyotime Biotechnology, China), superoxide dismutase (SOD), Cu/Zn SOD kit, malondialdehyde (MDA) kits (Nanjing Jiancheng, China), mitochondrial membrane potential (GMS10013.1, GENMED, USA) and catalase activity assay kit (Beyotime Biotechnology, China) were utilized for the present study. METHODS: Mouse embryonic cortical neurons were isolated and cultured with culture medium containing H2O2 (80 mu mol/L) and/or Mailuoning (1.25 mu g/mL) for 24 hours. MAIN OUTCOME MEASURES: Neuronal viability and death were detected by methyl thiazolyl tetrazdium and flow cytometry; ROS production was determined by flow cytometry; mitochondrial membrane potential was detected using fluorescent staining; SOD activity was detected using a modified nitroblue tetrazolium method; Cu/Zn SOD and catalase activity was detected by spectrophotometry; and MDA was determined using the lipid peroxidation method. RESULTS: H2O2 increased ROS production and MDA concentration (P < 0.05), and decreased mitochondrial membrane potential, SOD, Cu/Zn SOD and catalase activity (P < 0.05); the number of surviving neurons (P < 0.05) was also reduced. Mailuoning reversed these changes. CONCLUSION: Mailuoning protects H2O2-induced injury in cortical cells by inhibiting ROS and MDA, increasing depolarization of mitochondrial membrane, and enhancing SOD and catalase activity.