Pro-apoptotic Effect and Its Mechanisms of Oridonin on Human Ovarian Cancer Cell SKOV3

Objective To investigate the effect of oridonin which is extractsed from Donglingcao on the suppression of growth and induction of apoptosis in human ovarian cancer SKOV3 cell,and explore its mechanism. Methods The growth inhibitory effect of oridonin with or without cisplatin on SKOV3 cells was detected by MTT assay;The morphological and ultrastructural changes of SKOV3 cells were observed by inverted microscope and transmission electron microscope,respectively;The effect of cell cycle and apoptosis rate of oridion on SKOV3 cells were examined by Flow Cytometry (FCM);The expression of bcl-2,bax and survivin mRNA of SKOV3 cells was detected by quantitative reversed transcription-polymerase chain reaction (QRT-PCR). Results (1)MTT assay showed that oridonin could significantly inhibit the proliferation of SKOV3 cells in time and dose-dependent manner,and the half maximal inhibitory concentration (IC₅₀) of 24,48,72 hours were 45.22,33.85，22.48 μmol/L,respectively；the inhibitory effect of oridonin combined with cisplatin was more obvious than either one used separately.(2)Inverted microscope observed that cell growth was obviously inhibited.(3)Apoptosis morphological changes about vacuolar degeneration,chromatic agglutination and nuclear condensation was detected by electron microscope in oridonin-treated SKOV3 cells.(4)Cell cycle analysis indicated that the oridonin-treated cells were arrested at the S and G2/M phases.(5)The results of AnnexinV-FITC/PI double-stained represented the apoptosis rate of SKOV3 cells treated with 10,20 and 30 μmol/L oridonin for 48 hours were（9.13±0.91）%,（18.89±1.79）%,（36.11±3.01）%,respectively,and the apoptotic rate increased significantly compared with control group,the difference was statistically significant(P<0.05).(6)QRT-PCR showed that the expression of bcl-2 and survivin declined and bax upregulated in oridonin-treated SKOV3 cells,and the difference was statistically significant compared with control group (P<0.05). Conclusion Oridonin can inhibit the proliferation and induce the apoptosis of SKOV3 cells，and its mechanism might be related to up-regulate the expression of bax and down-regulate the expression of bcl-2 and survivin.