目的 研究真菌桦褐孔菌中的代表化合物桦褐孔菌醇对人乳腺癌MCF-7 细胞的作用,为桦褐孔菌及桦褐孔菌醇在抗肿瘤方面的临床应用提供新的依据。方法 桦褐孔菌醇由传统植物化学方法从桦褐孔菌中提取分离得到。乳腺癌细胞系MCF-7 与不同浓度的桦褐孔菌醇共孵育,采用噻唑蓝(MTT)法检测细胞存活率;流式细胞术Annexin V/PI 双染色检测细胞凋亡;Western blotting 法检测半胱氨酸蛋白酶3(Caspase-3)和多聚ADP-核糖聚合酶(Poly ADP ribose polymerase,PARP)蛋白表达情况。结果 桦褐孔菌醇能够抑制MCF-7 细胞的生长,并可诱导MCF-7 细胞产生凋亡。浓度为25、50、100 μmol/L的桦褐孔菌醇作用MCF-7 细胞48 h 后,细胞凋亡率显著增加至28.62%、39.45%、53.18%,明显高于对照组凋亡率(3.21%);经过50 μmol/L 桦褐孔菌醇分别处理12、24、48 h 后,MCF-7 细胞Caspase-3 的活性形式cleaved Caspase-3 表达量显著增加;凋亡蛋白标志物PARP 裂解量升高,且呈时间依赖性。结论 桦褐孔菌醇能抑制MCF-7 细胞的增殖并诱导其凋亡,其作用机制推测与激活细胞Casepase-3 和PARP 有关。

Objective To study the induction of human MCF-7 breast cancer cell apoptosis by inotodiol isolated from Inonotus obliquus, a traditional Chinese medicinal fungi. Methods Inotodiol was isolated from the crude ethanol extract of I. obliquus and purified. Inotodiol at different concentration and human breast cancer MCF-7 cell line were co-incubated. Relative cell viabilities were determined by MTT method; apoptosis was analyzed by Annexin V/PI dual staining with flow cytometry; The protein expression levels of Caspase-3 and Poly ADP ribose polymerase (PARP) were detected by Western blotting. Results Inotodiol reduced the viability of MCF-7 cells dose- and time-dependently. Moreover, inotodiol induced the apoptosis in MCF-7 cells. The data of Western blotting showed that inotodiol up-regulated the expression levels of cleaved Caspase-3 and PARP, in a time-dependent manner. Conclusion Inotodiol could induce apoptosis in human breast cancer cells, which provides novel information for clinical application of inotodiol and its preparations for the breast cancer patients.