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 H202-induced primary cortical neuron injury in embryonic mice.DESIGN, TIME AND SETTING:Comparative observation and in v#ro 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 μmol/L) and/or Mailuoning (1.25 μg/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; mitochondriai 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. Mai/uoning 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.