Objective:To observe the protective effects of Panax Notoginseng Saponins(PNS) on hypoxia /hypoglycemia and reoxygenation injury of rat hippocampal neurons.Methods: The damaging models of hypoxia /hypoglycemia and reoxygenation were established on cultured rat hippocampal neurons.Apoptosis were measured by flow cytometry.Morphological changes and neuronal necrosis were observed with fluorescence microscope.Nitric oxide(NO) contents and the leakage of lactic dehydrogenase(LDH) were measured.Results: hypoxia/hypoglycemia cultures for 5 hours with reoxygenation afterwards induced neuronal apoptosis and necrosis

significantly increased NO contents and the leakage of LDH.The effect were increased with the extending time of reoxygenation.PNS showed significant decrease in the percentage of neuronal apoptosis and necrosis

and reduced NO contents and the leakage of LDH.Conclusion: PNS may play protectvie role on neuron injury induced by hypoxia /hypoglycemia and reoxygenation by decreasing neuron apoptosis and necrosis

and inhibiting the release of NO and LDH.