Green tea and tea polyphenols in cancer prevention.
The cancer-preventive effects of green tea and its main constituent (-)-epigallocatechin gallate [(-)-EGCG] are widely supported by results from epidemiological, cell culture, animal and clinical studies in the recent decade. In vitro cell culture studies show that tea polyphenols potently induce apoptotic cell death and cell cycle arrest in tumor cells but not in their normal cell counterparts. Green tea polyphenols affect several signal transduction pathways, including growth factor-mediated, the mitogen-activated protein kinase (MAPK)-dependent, and ubiquitin/proteasome degradation pathways. Epidemiological studies have suggested that the consumption of green tea lowers the risk of cancer. Various animal studies have revealed that treatment by green tea inhibits tumor incidence and multiplicity in different organ sites such as skin, lung, liver, stomach, mammary gland and colon. Phase I and II clinical trials were carried out recently to explore the anticancer effects of green tea in patients with cancer. At this time, more mechanistic research, animal studies, and clinical trials are necessary to further evaluate the role of green tea in cancer prevention.
Chen
Di
D
The Prevention Program, Barbara Ann Karmanos Cancer Institute, and Department of Pathology, Wayne State University, School of Medicine, Detroit, Michigan 48201, USA.
Daniel
Kenyon G
KG
Kuhn
Deborah J
DJ
Kazi
Aslamuzzaman
A
Bhuiyan
Mohammad
M
Li
Lianhai
L
Wang
Zhigang
Z
Wan
Sheng Biao
SB
Lam
Wai Har
WH
Chan
Tak Hang
TH
Dou
Q Ping
QP
D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis; D002986:Clinical Trials as Topic; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D020935:MAP Kinase Signaling System; D009369:Neoplasms / Q000453:epidemiology / Q000378:metabolism / Q000517:prevention & control*; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D059808:Polyphenols; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D015398:Signal Transduction; D013662:Tea; D025801:Ubiquitin / Q000378:metabolism
D016588:Anticarcinogenic Agents; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D013662:Tea; D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex