Abstract: AIM: To compare the influence of S. miltiorrhiza Bunge injection (SMBI) and S. przewalskii Maxim injection (SPMI) on H₂O₂-induced injury in PC12.METHODS: PC12 cells were cultured in vitro to compare the protective effects of SMBI and SPMI on cell injury induced by H₂O₂. The survival rate was measured by MTT method, and the apoptosis rate of PC12 cells was detected by flow cytometry, the protein expressions of bcl-2 and bax in PC12 cells were detected by immunocytochemistry staining method. RESULTS: When PC12 was damaged by H₂O₂, the rate of cell survival was degraded, and the rate of apoptosis was increased. SMBI and SPMI could alleviate the destroy effectively(P <0.05), they both could strengthen the expression of bcl-2(P <0.05) and lighten that of bax(P <0.05). CONCLUSION: The results suggested that SMBI and SPMI had comparable protective effect on H₂O₂-induced injury in vitro. The main effects of both injections were related to strengthening the expression of bcl-2 and lightening that of bax.

Key words: S. miltiorrhiza Bunge injection (SMBI), S. przewalskii Maxim injection (SPMI), H₂O₂, apoptosis, bcl-2, bax