Epigallocatechin gallate (EGCG), also known as Epigallocatechin 3-gallate, is a type of catechin and is the most abundant catechin in tea.
It is the ester of epigallocatechol and gallic acid.
According to one researcher epigallocatechin-3-gallate is an antioxidant that helps protect the skin from UV radiation-induced damage and tumor formation. Other studies have found that EGCG can make malignant brain tumor cells more sensitive to killing by the chemo-drug temozolomide; this was done in the laboratory with cultured human brain tumor cells; whether EGCG can achieve this effect in brain tumor patients as well remains to be investigated.
It is currently under study as a possible treatment for multiple sclerosis
It can be found in many nutritional supplements.
EGCG and HIV
There has been some research investigating the benefit of EGCG from green tea in the treatment of HIV
infection. One study examined the molecular binding of EGCG to the CD4
receptor molecule on human lymphocytes
. The CD4 receptor is the site where the HIV virus attaches to a cell before infecting it. To bind to CD4, HIV uses its own receptor gp120
. The study found "clear evidence of high-affinity binding of EGCG to the CD4 molecule" and "inhibition of gp120 binding to human CD4+ T cells." The mechanism is very similar to a new class of anti-HIV medications, the entry inhibitors
. For reasons not yet understood, EGCG seems to have an inhibitory effect on other steps of the HIV lifecycle, including suppression of reverse-transcriptase
concentration and decreased protease
kinetics. These effects have only been observed in laboratory studies, not in HIV+ individuals. The concentrations of EGCG used in the studies could not be reached by drinking green tea. More study into EGCG and HIV is currently underway.