| Objective Gliomas are the most common type of intracranial tumors, which account for about 50% of all the primary brain tumors.Because of their infiltrating and scalable growth,the tumor tissues often have no clear border with surrounding normal brain tissues.So surgery is hard to eradicate the tumor.What's more,the glioma cells are not sensitive to traditional radiotherapy and chemotherapy.All the above reasons cause the recurrence rate high and the survival time short after the operation. Currently,there is a lack of satisfactory clinical treatment. Oridonin is derived from a rabdosia plant of the family Labiatae. Recent laboratory and clinical studies have shown that oridonin has a wide range of antibacterial,antiviral,and anti-inflammatory effect. Particularly,its anti-tumor activity has aroused extensive attention. In this study, human glioma U251 cells are used to investigate apoptosis-induction effects of oridonin and its mechanisms in vitro.Methods The U251 cells were treated to different concentrations of oridonin for different time,then the MTT method was used to investigate the inhibitory effect of oridonin on U251 cells. After exposed to 32μmol/L oridonin for 24h,the cellular morphologic changes were observed by means of phase contrast microscopy and fluorescence microscopy. The apoptosis-induction effect of different concentrations of oridonin was evaluated by flow cytometry.The real-time PCR was performed to evaluate the expression of bcl-2, bax and caspase-3 after the U251 cells exposed to 32μmol/L oridonin for 24h.Results Oridonin could inhibit the growth of U251 cells significantly in a time- and dose-dependent manner. Marked morphological changes of cell apoptosis,such as chromatin margination, nuclear fragmentation, apoptotic body formation, and cell membrane stained green by Annexin V-FITC,were observed 24h later after the cells were exposed to oridonin. The apoptosis-induction effect of oridonin was in a dose-dependent manner (P<0.05).Along with the process of apoptosis, bcl-2 expression was down-regulated and bax,caspase-3 expressions were up-regulated (P <0.05)Conclusion Oridonin can inhibit cell growth by inducing apoptosis in U251 cells via down-regulating the expression of bcl-2 and up-regulating that of bax and caspase-3. |
