Proposed mechanisms of (-)-epigallocatechin-3-gallate for anti-obesity.
Green tea catechins (GTCs) are polyphenolic flavonoids formerly called vitamin P. GTCs, especially (-)-epigallocatechin-3-gallate (EGCG), lower the incidence of cancers, collagen-induced arthritis, oxidative stress-induced neurodegenerative diseases, and streptozotocin-induced diabetes. Also, inhibition of adipogenesis by green tea and green tea extract has been demonstrated in cell lines, animal models, and humans. The obesity-preventive effects of green tea and its main constituent EGCG are widely supported by results from epidemiological, cell culture, animal, and clinical studies in the last decade. Studies with adipocyte cell lines and animal models have demonstrated that EGCG inhibits extracellular signal-related kinases (ERK), activates AMP-activated protein kinase (AMPK), modulates adipocyte marker proteins, and down-regulates lipogenic enzymes as well as other potential targets. Also, the catechin components of green tea have been shown to possess anti-carcinogenic properties possibly related to their anti-oxidant activity. In addition, it was shown that dietary supplementation with EGCG could potentially contribute to nutritional strategies for the prevention and treatment of type 2 diabetes mellitus. In this review, the biological activities and multiple mechanisms of EGCG in cell lines, animal models, and clinical observations are explained.
Moon
Hyun-Seuk
HS
School of Agricultural Biotechnology, Seoul National University, Seoul 151-921, South Korea.
Lee
Hong-Gu
HG
Choi
Yun-Jaie
YJ
Kim
Tae-Gyu
TG
Cho
Chong-Su
CS
D055372:AMP-Activated Protein Kinases; D017667:Adipocytes / Q000201:enzymology / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism; D009765:Obesity / Q000201:enzymology / Q000378:metabolism / Q000517:prevention & control*; D010936:Plant Extracts / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D013662:Tea
D000975:Antioxidants; D009097:Multienzyme Complexes; D010936:Plant Extracts; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate; D017346:Protein Serine-Threonine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D055372:AMP-Activated Protein Kinases