中文摘要：

目的：研究香加皮乙酸乙酯提取物（ethyl acetate extract from Cortex Periplocae，CPEAE）诱导人乳腺癌细胞系MCF-7凋亡作用及其作用机制。方法：采用MTT法观察不同浓度CPEAE对乳腺癌细胞株MCF-7增殖的抑制作用；应用吖啶橙／溴化乙锭（AO／EB）荧光染色法和透射电镜观察凋亡细胞形态；应用流式细胞术分析CPEAE对细胞凋亡率的影响；RT—PCR法检测用药前后细胞凋亡相关基因survivin和bax的mRNA表达情况。结果：CPEAE呈浓度及时间依赖性抑制MCF-7细胞的增殖（P＜0．05），作用48h的IC50为（0．943±0．005）〉g／mL。CPEAE作用48h后MCF-7细胞发生了特征性的凋亡形态学改变，流式细胞仪检测可见典型的凋亡峰，2．0μg／mL CPEAE作用72h时细胞的凋亡率达（30．24±1．26）％。CPEAE作用后MCF-7细胞的survivin mRNA表达降低，而bax mRNA表达增加。结论：香加皮乙酸乙酯提取物（CPEAE）可诱导乳腺癌细胞系MCF-7发生凋亡，可能通过下调survivin基因、上调bax基因的mRNA水平而发挥诱导细胞凋亡作用。

英文摘要：

Objective：To investigate the effect of ethyl acetate extract from Cortex Periplocae（CPEAE）on apoptosis of human breast cancer cell line MCF-7 and to discuss its mechanism. Methods： Inhibitory effect of CPEAE at different concentrations on MCF 7 proliferation was tested by MTT method. The morphological changes of cell apoptosis were observed by acridine or ange/ethidium bromide （AO/EB） staining and transmission electron microscopy. Cell apoptotic ratio was measured by flow cytometry （FCM）. The mRNA levels of apoptosis-associated genes, survivin and bax, were detected by RT-PCR before and after treatment with CPEAE, respectively. Results：CPEAE inhibited proliferation of MCF-7 cells in a concentration- and time-depend ent manner with IC50 value（for 48 h） of （0. 943 ± 0. 005）μg/mL （P〈0.05）. The characteristic morphological changes of apopto sis were observed in MCF-7 cells after exposed to CPEAE. A typical subdiploid peak was detected by flow cytometry. The apop totic ratio reached （30.24±1.26）% after CPEAE 2.0μg/mL treatment for 72 h. CPEAE treatment decreased the expression of survivin mRNA but increased expression of bax mRNA in MCF-7 cells. Conclusion：CPEAE induced apoptosis of human breast cancer cell line MCF-7 through down regulation of survivin mRNA expression and up regulation of bax mRNA expression.