Tang Center for Herbal Medicine Research, University of Chicago, Chicago, IL 60637, USA.
Nutrients. 2012 Nov 8;4(11):1679-91. doi: 10.3390/nu4111679.
Green tea is a popular drink consumed daily by millions of people around the world. Previous studies have shown that some polyphenol compounds from green tea possess anticancer activities. However, systemic evaluation was limited. In this study, we determined the cancer chemopreventive potentials of 10 representative polyphenols (caffeic acid, CA; gallic acid, GA; catechin, C; epicatechin, EC; gallocatechin, GC; catechin gallate, CG; gallocatechin gallate, GCG; epicatechin gallate, ECG; epigallocatechin, EGC; and epigallocatechin gallate, EGCG), and explored their structure-activity relationship. The effect of the 10 polyphenol compounds on the proliferation of HCT-116 and SW-480 human colorectal cancer cells was evaluated using an MTS assay. Cell cycle distribution and apoptotic effects were analyzed by flow cytometry after staining with propidium iodide (PI)/RNase or annexin V/PI. Among the 10 polyphenols, EGCG showed the most potent antiproliferative effects, and significantly induced cell cycle arrest in the G1 phase and cell apoptosis. When the relationship between chemical structure and anticancer activity was examined, C and EC did not show antiproliferative effects, and GA showed some antiproliferative effects. When C and EC esterified with GA to produce CG and ECG, the antiproliferative effects were increased significantly. A similar relationship was found between EGC and EGCG. The gallic acid group significantly enhanced catechin's anticancer potential. This property could be utilized in future semi-synthesis of flavonoid derivatives to develop novel anticancer agents.
绿茶是一种深受全世界数百万人喜爱的饮品。先前的研究表明，绿茶中的一些多酚化合物具有抗癌活性。然而，系统评价有限。在这项研究中，我们确定了 10 种代表性多酚（咖啡酸、CA；没食子酸、GA；儿茶素、C；表儿茶素、EC；表没食子儿茶素、GC；儿茶素没食子酸酯、CG；表没食子儿茶素没食子酸酯、GCG；表儿茶素没食子酸酯、ECG；表没食子儿茶素、EGC；和表没食子儿茶素没食子酸酯、EGCG）的癌症化学预防潜力，并探讨了它们的结构-活性关系。采用 MTS 法评估了 10 种多酚化合物对 HCT-116 和 SW-480 人结肠癌细胞增殖的影响。用碘化丙啶（PI）/RNase 或 Annexin V/PI 染色后，通过流式细胞术分析细胞周期分布和凋亡效应。在 10 种多酚中，EGCG 表现出最强的抗增殖作用，并显著诱导细胞周期停滞在 G1 期和细胞凋亡。当检查化学结构与抗癌活性之间的关系时，C 和 EC 没有表现出抗增殖作用，而 GA 则表现出一些抗增殖作用。当 C 和 EC 与 GA 酯化生成 CG 和 ECG 时，抗增殖作用显著增强。在 EGC 和 EGCG 之间也发现了类似的关系。没食子酸基团显著增强了儿茶素的抗癌潜力。这一特性可用于未来黄酮类衍生物的半合成，以开发新型抗癌药物。
