Green tea polyphenols in the prevention of colon cancer.
Several plant-based nutrients and non-nutrients that can inhibit mutagenesis and proliferation have been identified. Some of the most promising nutrients identified as chemopreventive agents in colon cancer prevention include isoflavones, curcumin, calcium, vitamin D and more recently Green tea polyphenols (GTP). In addition to inhibiting mutagenesis and proliferation, these compounds are relatively non-toxic, are of low cost and can be taken orally or as a part of the daily diet. Epidemiological and laboratory studies have identified epigallocatechin gallate (EGCG) in green tea polyphenols (GTP), as the most potent chemopreventive agent that can induce apoptosis, suppress the formation and growth of human cancers including colorectal cancers (CRC). It is only logical then, that future clinical studies should focus on examining the efficacy of phytochemicals such as EGCG in cancer chemoprevention as an alternative to pharmacological agents, especially in populations where administration of COX-2 inhibitors, Aspirin and NSAIDS is contraindicated. The goal of this review is to provide the rationale, and discuss the use of EGCG in GTP as a chemopreventive agent for prevention of colon carcinogenesis and present evidence for the efficacy and safety of these agents based on epidemiological, animal, in vitro studies and Phase I clinical trials.
Kumar
Nagi
N
Division of Health Outcomes and Behavior, H. Lee Moffitt Cancer Center and Research Institute, University of South Florida College of Medicine, Tampa, Florida 33612, USA. kumar@moffitt.usf.edu
Shibata
David
D
Helm
James
J
Coppola
Domenico
D
Malafa
Mokenge
M
D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D017321:Clinical Trials, Phase I as Topic; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D005419:Flavonoids / Q000032:analysis / Q000627:therapeutic use; D006801:Humans; D051379:Mice; D010636:Phenols / Q000032:analysis / Q000627:therapeutic use; D059808:Polyphenols; D051381:Rats; D013662:Tea / Q000737:chemistry*
D016588:Anticarcinogenic Agents; D014408:Biomarkers, Tumor; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate