中文摘要：

目的探讨冬凌草甲素对胰腺癌PANC-1细胞生长抑制以及促进凋亡的机制。方法采用MTT还原法检测冬凌草甲素对PANC-1细胞生长的抑制作用;碘化丙啶（PI）染色和Hoechst33342染色法观察细胞形态学的变化;PI染色流式细胞术检测细胞周期分布;膜联蛋白V（Annexin V）/PI双标流式细胞术测定凋亡细胞比率;分光光度法检测Caspase-3酶活性;Western blotting法测定Caspase-3酶原（pro-caspase-3）、Bax和Bcl-2蛋白的表达变化。结果冬凌草甲素对胰腺癌细胞PANC-1具有明显的生长抑制作用,并呈现明显的剂量依赖性;细胞形态学观察发现,冬凌草甲素可诱导PANC-1细胞凋亡;细胞周期被阻滞在G2/M期,细胞凋亡率随药物浓度的增加而增加;Caspase-3酶原被激活;Bax蛋白表达量增加,Bcl-2蛋白表达无明显变化。结论冬凌草甲素可通过G2/M细胞周期阻滞和诱导凋亡抑制胰腺癌细胞PANC-1的生长,其分子机制可能是通过改变Bax/Bcl-2的表达比率,激活Caspase-3,从而促进PANC-1细胞发生凋亡。

英文摘要：

Objective：To investigate the mechanism of oridonin on proliferation and apoptosis of PANC-1 cells in vitro.Methods：The anti-proliferation effect of oridonin was measured by MTT assay,PI staining and Hoechst 33342 staining were used to detect morphologic changes,the cell cycle distribution and the percentage of apoptosis were determined by flow cytometer,Caspase-3 activity was measured by spectrophotometry,and expression of pro-caspase-3,Bax and Bcl-2 were detected by Western blotting analysis.Results：Oridonin inhibited the growth of PANC-1 cells in a dose-dependent manner.Morphological changes indicated that oridonin induced PANC-1 cells apoptosis,the cell cycle was arrested at G2/M phase and the apoptosis rate increased in a dose-dependent manner,Pro-caspase-3 was activated,and expression of Bax was up-regulated,whereas expression of Bcl-2 had no obvious change.Conclusion：Oridonin can inhibit the growth of PANC-1 cells possibly by inducing G2 /M phase cell cycle arrest and apoptosis.The molecular mechanism of apoptosis may be mediated by the change of the Bax/Bcl-2 ratio and the activation of pro-caspase-3.