Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2014 Jan 10:2:187-95.
doi: 10.1016/j.redox.2013.12.022. eCollection 2014.

New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate

Hae-Suk Kim  1 , Michael J Quon  2 , Jeong-A Kim  3
Affiliations
Review

New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate

Hae-Suk Kim et al. Redox Biol. .

Abstract

Green tea is rich in polyphenol flavonoids including catechins. Epigallocatechin 3-gallate (EGCG) is the most abundant and potent green tea catechin. EGCG has been extensively studied for its beneficial health effects as a nutriceutical agent. Based upon its chemical structure, EGCG is often classified as an antioxidant. However, treatment of cells with EGCG results in production of hydrogen peroxide and hydroxyl radicals in the presence of Fe (III). Thus, EGCG functions as a pro-oxidant in some cellular contexts. Recent investigations have revealed many other direct actions of EGCG that are independent from anti-oxidative mechanisms. In this review, we discuss these novel molecular mechanisms of action for EGCG. In particular, EGCG directly interacts with proteins and phospholipids in the plasma membrane and regulates signal transduction pathways, transcription factors, DNA methylation, mitochondrial function, and autophagy to exert many of its beneficial biological actions.

Keywords: Anti-oxidant; EC, epicatechin; ECG, epicatechin gallate; EGC, epigallocatechin; EGCG; EGCG, epigallocatechin 3-gallate; Polyphenol; Pro-oxidant.

PubMed Disclaimer

Figures

None
Graphical abstract
Fig. 1
Fig. 1
EGCG-activated eNOS pathways that improve cardiovascular function and anti-cancer effect in the presence of PDE5 inhibitor. EGCG elevates cGMP levels through a specific receptor 67LR that stimulates the Akt/eNOS pathway. This pathway leads to vasodilation which contributes to improvement of cardiovascular function. In cancer cells, inhibition of PDE5 by treatment with Vardenafil leads to sustained elevations of cGMP levels. This elevated cGMP activates PKCδ/acidic sphingomyelinase (ASM) that contributes to apoptosis.
Fig. 2
Fig. 2
The roles of 67LR as a specific receptor for EGCG. EGCG has multiple biological actions mediated through 67LR by enhancing (red) and inhibiting (blue) specific pathways.
Fig. 3
Fig. 3
Metabolic and vascular functions of EGCG. A schematic diagram showing the mechanisms for the activation of AMPK by EGCG. AMPK is a key molecule that regulates enzymes involved with energy metabolism and endothelial functions.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Ahn H.Y., Hadizadeh K.R., Seul C., Yun Y.P., Vetter H., Sachinidis A. Epigallocathechin-3 gallate selectively inhibits the PDGF-BB-induced intracellular signaling transduction pathway in vascular smooth muscle cells and inhibits transformation of sis-transfected NIH 3T3 fibroblasts and human glioblastoma cells (A172) Mol. Biol. Cell. 1999;10:1093–1104. - PMC - PubMed
    1. Aktas O., Prozorovski T., Smorodchenko A., Savaskan N.E., Lauster R., Kloetzel P.M., Infante-Duarte C., Brocke S., Zipp F. Green tea epigallocatechin-3-gallate mediates T cellular NF-kappa B inhibition and exerts neuroprotection in autoimmune encephalomyelitis. J. Immunol. 2004;173:5794–5800. - PubMed
    1. Alvarez E., Campos-Toimil M., Justiniano-Basaran H., Lugnier C., Orallo F. Study of the mechanisms involved in the vasorelaxation induced by (-)-epigallocatechin-3-gallate in rat aorta. Br. J. Pharmacol. 2006;147:269–280. - PMC - PubMed
    1. Aneja R., Hake P.W., Burroughs T.J., Denenberg A.G., Wong H.R., Zingarelli B. Epigallocatechin, a green tea polyphenol, attenuates myocardial ischemia reperfusion injury in rats. Mol. Med. 2004;10:55–62. - PMC - PubMed
    1. Babich H., Zuckerbraun H.L., Weinerman S.M. In vitro cytotoxicity of (-)-catechin gallate, a minor polyphenol in green tea. Toxicol. Lett. 2007;171:171–180. - PubMed

Publication types

MeSH terms

LinkOut - more resources

-