Effects of tea polyphenols on signal transduction pathways related to cancer chemoprevention.
The inhibition of carcinogenesis by tea and tea polyphenols has been demonstrated in different animal models by many investigators. The mechanisms of this inhibitory activity have also been investigated extensively, mostly in cell culture systems, but no clear conclusion can be reached concerning the cancer preventive mechanisms in vivo. In this article, we reviewed the possible mechanisms, which include the inhibition of specific protein kinase activities, blocking receptor-mediated functions, and inhibition of proteases. These events may lead to cell cycle regulation, growth inhibition, enhanced apoptosis, inhibition of angiogenesis, and inhibition of invasion and metastases. The possible complications of translating results obtained in cell culture studies to animals and humans are discussed. It is likely that multiple signal transduction pathways are involved in the inhibition of carcinogenesis by tea constituents. The relative importance of these pathways needs to be determined in vivo.
Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, 164 Frelinghuysen Road, Piscataway, NJ 08854 8020, USA.
Zhe
Z
Hou
Joshua D
JD
Lambert
Khew-Voon
KV
Chin
Chung S
CS
Yang
D000818:Animals; D018890:Chemoprevention; D005419:Flavonoids / Q000627:therapeutic use*; D006801:Humans; D009369:Neoplasms / Q000517:prevention & control*; D010636:Phenols / Q000627:therapeutic use*; D059808:Polyphenols; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D013662:Tea / Q000737:chemistry*
D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D013662:Tea