Objective: To investigate the protective effect and mechanism of Tongluo Huatan capsule on H2O2-induced apoptosis in PC12 cells. Method: PC12 cells were cultured

and the cell viability of PC12 cells injured by different H2O2 concentrations and proliferated by different Tongluo Huatan Capsule were observed by MTT assay to determine the concentration that will cause a H2O2-induced apoptosis model of PC12 cells and the security concentrations of Tongluo Huatan Capsule for PC12 cells. PC12 cells in the logarithmic growth phase were divided into control group

model group and low

medium and high dose Tongluo Huatan capsule treatment groups. Apoptosis of PC12 cells were induced by H2O2 at the concentration of 200 μmol·L-1

MTT assay was used to detect the cell viability of PC12 cells protected by Tongluo Huatan capsule at different concentarions

Hoechst33342 fluorescent staining was used to observe morphological changes of cell apoptosis

the flow cytometry were used to detect the rate of apoptosis in PC12 cells

and the Western blot technology was used to detect the expressios of protein CytC and Caspase-3. Result: PC12 cells were injured by H2O2 at 200 μmol·L-1 concentration

while Tongluo Huatan capsule at less than or equal to the concentration of 100 μmol·L-1did not inhibit the cell viability of PC12 cells. Compared with the model group

Tongluo Huatan capsule groups improved cell viability (P<0.01)

decreased apoptotic cells and apoptosis rate (P<0.01)

and decreased the expression of Cytc and Caspase-3 (P<0.01) which was related to doses Tongluohuatan capsule. Conclusion: Tongluo Huatan capsule can inhibit H2O2-induced apoptosis in PC12 cells

while the mechanism may be related to the inhibition of the expression of apoptosis-related protein CytC and caspase-3 in the mitochondrial pathway.