毒理性
亚洲酸是一种存在于药用植物中的五环三萜类化合物。本研究调查了这种化合物对人类结肠腺癌细胞系HT-29的细胞毒性效应,以及它对抗癌药物伊立替康盐酸盐(CPT-11)的增效作用。亚洲酸在HT-29细胞中以剂量依赖性方式表现出细胞毒性。观察到剂量依赖性的DNA片段化、annexin阳性的凋亡细胞和caspase-3的激活。caspase-3抑制剂以浓度依赖性方式抑制了DNA梯状物的形成。Bcl-2和Bcl-XL蛋白因亚洲酸处理而减少。这些结果表明,亚洲酸通过caspase-3激活在HT-29细胞中诱导了凋亡。进一步检测了CPT-11和亚洲酸联合处理对HT-29细胞的细胞毒性效应。同时处理或依次先暴露于亚洲酸再暴露于CPT-11显示出加性效应。当细胞首先暴露于CPT-11然后再暴露于亚洲酸时,观察到协同作用。这些结果提示,亚洲酸可以作为提高结肠癌细胞对CPT-11治疗敏感性的药物,或者作为减少CPT-11不良反应的药物。
Asiatic acid is a pentacyclic triterpene contained in medicinal plants. The cytotoxic effect of this compound and its augmentative effect on the anticancer drug irinotecan hydrochloride (CPT-11) were investigated in the human colon adenocarcinoma cell line HT-29. Asiatic acid dose-dependently showed cytotoxicity in HT-29 cells. DNA fragmentation, annexin-positive apoptotic cells, and caspase-3 activation were observed in a dose-dependent manner. A caspase-3 inhibitor suppressed the DNA ladder formation in a concentration-dependent manner. Bcl-2 and Bcl-XL proteins were decreased by asiatic acid treatment. These results indicate that asiatic acid induced apoptosis in HT-29 cells via caspase-3 activation. Cytotoxic effects of combined treatment with CPT-11 and asiatic acid on HT-29 cells were further examined. Simultaneous treatment or sequential exposure first to asiatic acid and then to CPT-11 showed an additive effect. Synergism was observed when cells were first exposed to CPT-11 and then to asiatic acid. These results suggest that asiatic acid can be used as an agent for increasing sensitivity of colon cancer cells to treatment with CPT-11 or as an agent for reducing adverse effects of CPT-11.
来源:Hazardous Substances Data Bank (HSDB)