Phytochemicals are biologically active plant-derived compounds and are thought to be responsible for the health-promoting effects of foods such as fruits, vegetables, and teas.These chemicals include flavonoids, lignans, and catechins, among others. Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin.

Source and effects

EGCG is a phytochemical isolated from Camilla sinensis, the plant from which green, white, and black teas are made. The green tea derivatives from the buds and leaves contain epicatechin, epigallocatechin, epicatechin-3-gallate, and epigallocatechin-3-gallate, which posses antioxidant, anti-inflammatory, and anticarcinogenic properties.

The antioxidant effects presumably work by eliminating reactive oxygen species and inhibiting nitric oxide synthetase, lipoxygenase, cyclooxygenase, and lipid peroxidase. Additionally, green tea is purported to inhibit the infiltration of inflammatory cells, such as macrophages and neutrophils, and the resultant decrease of pro-inflammatory cytokines contributes to the anti-inflammatory activity. Lastly, the inhibition of carcinogen- DNA binding and subsequent tumorigenesis leads to the anticarcinogenic property.

Experimental Study

Several studies suggest that botanical therapies may be useful as preventative agents. Domingo et al. show that EGCG cream suppresses vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1α (HIF-1 α), two compounds that stimulate angiogenesis.Based on histochemical analysis of treated skin, they suggest that the cream may prevent or slow development of telangiectasias and erythema and thus may be useful as a preventative therapy. 

However, chromameter measurements did not show a significant difference in the clinically observable erythema between a split-face assessment of topical EGCG and placebo. Conceivably, measurable clinical improvement may not have been evident in this trial after only six weeks of topical therapy.Of note, this split-face study included only four participants.