Objective: To investigate apoptosis induction effects of oridonin(Ori)on human kidney carcinoma cells and its mechanisms in vitro. Method: The MTT assay was used to measure the inhibitory effects of oridonin at the concentration of 1×104/mL on A-704 cells.The apoptosis rate of A-704 cells which were impacted by Ori for 24 hours was examined by Annexin V-FITC/PI staining of Flow cytometry with the increase of the concentration

the number of apoptotic cells and necrotic cells were increased

the higher the concentration

the more the ratio of necrotic cells increased expression of Bax

Caspase-3 and Bcl-2 of A-704 cells which were impacted by 32 μmol·L-1oridonin for 24 hours were evaluated by Real-time PCR. Result: Ori could inhibit the growth of A-704 cells significantly in a time-dependent and dose-dependent manner. The inhibition rate of A-704 cells which were impacted by 64 μmol·L-1oridonin for 24 hours could be reach 73%.With the concentration of Ori increased

the number of apoptotic and necrosis cells both increased. The higher concentration

the more rate of necrotic cells increased. The ratio of necrosis cells of A-704 cells which were impacted by 64 μmol·L-1Ori for 24 hours could be reach 32.4%.Along with the extention of time

Bax and Caspase-3 expressions were up-regulated

Bcl-2 expression was down-regulated (all P<0.05). Conclusion: Ori can inhibit A-704 cells growth by induction of apoptosis in cells via activation of Caspase-3 as well as up-regulation of Bax and down-regulation of Bcl-2 gene expression.