Abstract: OBJECTIVE To investigate the effect of n-butanol extract from Euryale ferox Salisb. against H₂O₂-induced oxidative injury of PC12 cells and explore the protective mechanism of this active components against Alzheimer's disease cell model. METHODS The n-butanol extracts of semen euryales were separated by the column chromatography of polyamide. PC12 cells were cultivated in vitro and treated with 200 μmol/L H₂O₂ for 8 h to establish the oxidative damage model. Cell viabilities were determined by MTT assay， and the activities of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were analyzed in cell-culture medium by the corresponding kits. RT-qPCR was used to detect the mRNA expression of APP， BACE-1 and GSK-3β . RESULTS Compared with the model group， the 50%， 70%， 95% concentration of alcohol in n-butanol components of semen euryales improved the cell viability of PC12(P<0.05). The 70% alcohol components significantly increased SOD activity and decreased the content of MDA in culture supernatants (P<0.05) and significantly down-regulated the expression of GSK-3β (P<0.01). CONCLUSION The 70% and 95% alcohol components of n-butanol extracts of semen euryales shows significant protective effects on oxidative stress-induced cell injury. The protection mechanism may be related to the increased SOD activity， the reduced the emission of MDA， and the inhibition the key genes associated with the accumulation of Aβ.