Inhibitory effects of polyphenol-enriched extract from Ziyang tea against human breast cancer MCF-7 cells through reactive oxygen species-dependent mitochondria molecular mechanism.

Abstract

A polyphenol-enriched extract from selenium-enriched Ziyang green tea (ZTP) was selected to evaluate its antitumor effects against human breast cancer MCF-7 cells. In ZTP, (-)-epigallocatechin gallate (28.2%) was identified as the major catechin, followed by (-)-epigallocatechin (5.7%) and (-)-epicatechin gallate (12.6%). ZTP was shown to inhibit MCF-7 cell proliferation (half maximal inhibitory concentration, IC50 = 172.2 μg/mL) by blocking cell-cycle progression at the G0/G1 phase and inducing apoptotic death. Western blotting assay indicated that ZTP induced cell-cycle arrest by upregulation of p53 and reduced the expression of CDK2 in MCF-7 cells. ZTP-caused cell apoptosis was associated with an increase in Bax/Bcl-2 ratio, and activation of caspase-3 and -9. MCF-7 cells treated with ZTP also showed an overproduction of reactive oxygen species, suggesting that reactive oxygen species played an important role in the induction of apoptosis in MCF-7 cells. This is the first report showing that ZTP is a potential novel dietary agent for cancer chemoprevention or chemotherapy.

• Authors: Wenfeng Li, Nianwu He, Lingmin Tian, Xiaolong Shi, Xingbin Yang
• Journal: Journal of food and drug analysis (J Food Drug Anal) Vol. 24 Issue 3 Pg. 527-538 (07 2016) ISSN: 2224-6614 [Electronic] China (Republic : 1949- )
• PMID: 28911558 (Publication Type: Journal Article)
• Copyright: Copyright © 2016. Published by Elsevier B.V.

Chemical References

• Reactive Oxygen Species
• Tea

Topics

• Breast Neoplasms
• Humans
• MCF-7 Cells
• Mitochondria
• Reactive Oxygen Species
• Tea