Epigallocatechin Gallate (EGCG) is the most effective cancer chemopreventive polyphenol in green tea

• Published in: Nutrients 2012-11, Vol.4 (11), p.1679-1691
• Main Authors: Du, Guang-Jian, Zhang, Zhiyu, Wen, Xiao-Dong, Yu, Chunhao, Calway, Tyler, Yuan, Chun-Su, Wang, Chong-Zhi
• Format: Article
• Language: English
• Subjects: anticancer; Anticarcinogenic Agents - pharmacology; apoptosis; Apoptosis - drug effects; Catechin - analogs & derivatives; Catechin - chemistry; Catechin - pharmacology; cell cycle; Cell Cycle Checkpoints - drug effects; Cell growth; Cell Line, Tumor; Cell Proliferation - drug effects; Cocoa; Colorectal Neoplasms - pathology; EGCG; epigallocatechin gallate; flavonoids; gallic acid; HCT116 Cells; human colorectal cancer; Humans; Models, Molecular; Molecular Structure; Polyphenols; Polyphenols - chemistry; Polyphenols - pharmacology; Structure-Activity Relationship; Tea; Tea - chemistry; tea polyphenols
• ISSN: 2072-6643; 2072-6643
• 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.