中文摘要：

目的 探讨雷公藤甲素对U251细胞自噬活性的影响及机制。方法 采用四甲基偶氮唑蓝（MTT）法检测雷公藤甲素对U251细胞的增殖抑制率、半数抑制浓度（IC50）;免疫荧光化学法测定细胞中LC3-Ⅱ表达,Western blot法测定LC3-Ⅱ/LC3-Ⅰ、Beclin-1、磷酸化P70、磷酸化Erk、磷酸化AKT蛋白的表达。结果 雷公藤甲素作用于U251细胞后,细胞增殖受抑制,24h的IC50为0.73μmol/L,48h的IC50为0.27μmol/L。免疫荧光法测定6、12、24h后LC3-Ⅱ水平增高;Western blot法测定LC3-Ⅱ水平、LC3-Ⅱ/LC3-Ⅰ比值随时间增高;Beclin-1水平增高,磷酸化P70、磷酸化Erk表达降低、磷酸化AKT无明显变化。结论雷公藤甲素可抑制U251细胞增殖并促进自噬,并可通过上调Beclin-1表达和抑制mTOR的活性来促进自噬。

英文摘要：

Objective . To explore the variation of autophagic activity in U251 ceils after treatment with Triptolide and its mechanisms. Methods We measured the proliferation inhibition rate, half inhibitory concentration （ICso） by MTT assay; LC3-Ⅱ protein expression were tested by immunofluorescence assay; protein expression of LC3-Ⅱ/LC3-Ⅰ , Beclin-1, Phospho-P70, Phos- pho-Erk and Phospho-AKT were measures by Western bIot. Results After treatment with Triptolide, the proliferation of U251 cells was inhibited,with the IC50 of 0.73 μmol/L at 24 h and the IC50 of 0.27 μmol/L at 48 h;the expression of LC3-Ⅱ were in- creased at 6,12,24 h;the expression of LC3-Ⅱ , LC3-Ⅱ/LC3-1 and Beclin-1 increased, the expression of Phospho-P70 and Phos- pho-Erk decreased and the expression of Phospho-AKT had no obvious change. Conclusion Triptolide could inhibit the prolifera- tion of U251 cells and induce cell autophagy;Triptolide could increase the autophagy by upregulating Beclin-1 expression and inhibi- ting the activity of mTOR.