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

Wenfeng Li; Nianwu He; Lingmin Tian; Xiaolong Shi; Xingbin Yang

doi:10.1016/j.jfda.2016.01.005

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

J Food Drug Anal. 2016 Jul;24(3):527-538. doi: 10.1016/j.jfda.2016.01.005. Epub 2016 Feb 23.

Authors

Wenfeng Li¹, Nianwu He², Lingmin Tian¹, Xiaolong Shi¹, Xingbin Yang¹

Affiliations

¹ Key Laboratory of Ministry of Education for Medicinal Resource and Natural Pharmaceutical Chemistry, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, China.
² College of Biopharmaceutical and Food Engineering, Shangluo University, Shangluo, China.

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.

Keywords: MCF-7 cells; Ziyang green tea; apoptosis; breast cancer; polyphenols.

MeSH terms

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

Substances

Reactive Oxygen Species
Tea

Grants and funding

This work was supported by the National Natural Science Foundation of China (C31171678); the Fundamental Research Funds for the Central Universities of Shaanxi Normal University, China (GK201103004); and the Scientific Research Foundation of Shangluo University (13SKY-FWDF007).