本研究对苦丁茶黄酮通过caspases（半胱氨酸蛋白酶蛋白）活化诱导人HSC-3口腔癌细胞凋亡的效果进行了观察。通过MTT实验发现在0~150 μg/mL浓度下，苦丁茶黄酮可以抑制HSC-3癌细胞的生长，但不影响HOK口腔角质细胞（正常细胞）的增殖。150 μg/mL浓度下苦丁茶黄酮对HSC-3癌细胞的生长抑制率（78.9%）超过同浓度下市售大豆异黄酮胶囊物（42.8%）。通过检测癌细胞的mRNA表达强度发现，相对于对照癌细胞，苦丁茶黄酮可以上调HSC-3癌细胞中caspase-3、caspase-8、caspase-9、Bax（Bcl-2相关X蛋白）、Fas（凋亡相关因子）和FasL（凋亡相关因子配体）的表达，下调Bcl（B淋巴细胞瘤）-2、Bcl-xL、cIAP（细胞凋亡抑制蛋白）-1和cIAP-2的表达，并且随着苦丁茶黄酮浓度的升高，这些趋势进一步加强。实验结果证实苦丁茶黄酮可以在体外通过caspases的活化实现诱导HSC-3癌细胞凋亡的效果。

The apoptosis-inducing effects of Kuding tea flavonoids on human oral cancer HSC-3 cells through caspase activation (cysteinyl aspartate specific proteinase) were observed in this study. The MTT assay showed that Kuding tea flavonoids inhibited the growth of HSC-3 cancer cells at a concentration of 0~150 μg/mL; however, the flavonoids did not influence the proliferation of human oral keratinocyte cells (normal cells). Kuding tea flavonoids (concentration, 150 μg/mL) showed a better growth inhibitory effect (78.9%) on HSC-3 cancer cells compared to the soybean isoflavones capsule substance (42.8%) available in the market. Analysis of the mRNA expression in cancer cells showed that Kuding tea flavonoids upregulated caspase-3, caspase-8, caspase-9, Bcl-2 associated X protein (Bax), factor associated suicide (Fas), and Fas ligand (FasL) mRNA expressions, and downregulated the expressions of B-cell lymphoma-2 (Bcl-2), Bcl-xL, cellular inhibitor of apoptosis protein-1 (cIAP-1), and cIAP-2 mRNA, compared to the control. This increase and decrease in mRNA expression was observed to be correlated to the increase in concentration of Kuding tea flavonoids. These results demonstrated that Kuding tea flavonoids induced in vitro apoptosis in HSC-3 cancer cells via caspase activation.

重庆第二师范学院引进高层次人才科研启动费；重庆市医学科技计划资助项目(2011-1-060)；重庆第二师范学院创新团队计划（KYC-cxtd03-20141002）