Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid , and is a type of catechin. EGCG is the most abundant catechin in tea and is a potent antioxidant that may have therapeutic applications in the treatment of many disorders (e.g. cancer). It is found in green tea, but not black tea ; during black tea production, the catechins are converted to theaflavins and thearubigins.[3] It is also found in various vegetables, nuts, as well as carob powder at 109 mg per 100g. [4] In a high
temperature environment, an epimerization change is more likely to occur; however as exposure to boiling water for 30 straight minutes leads to only a 12.4% reduction in the total amount of EGCG, the amount lost in a brief exposure is insignificant. In fact, even when special conditions were used to create temperatures well above that of boiling water, the amount lost increased only slightly.
EGCG can be found in many supplements.
Pharmacology
EGCG is an inhibitor of the enzymes:
Histone acetyltransferase[6]
DNA methyltransferase [7]
Fatty acid synthase [8]
Glutamate dehydrogenase [9]
Topoisomerase I and II [10]
and
antagonises the Epidermal growth factor receptor 1 and Epidermal growth factor receptor 2.
[11] Research on potential therapeutic
usesEGCG has been the subject of a
number of studies investigating its
potential use as a therapeutic for a
broad range of disorders:
HIVA large amount of research has been conducted investigating the benefit of EGCG from green tea in the treatment of HIV infection, where EGCG has been shown to reduce plaques related to AIDS-related dementia in the laboratory, as well as block gp120 . [12][13][14] However, these effects have yet to be
confirmed in live human trials, and it does not imply that green tea will cure or block HIV infection, but it may help regulate viral load as long as it is not involved in adverse drug reactions. 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. [15]
CancerThere is increasing evidence to show that EGCG – along with other flavonoids – can be beneficial in treating brain, [16] prostate,[17][18] cervical[19] and bladder[20] cancers.
EGCG has been shown to bind and inhibit the anti-apoptotic protein Bcl-xl ,[21] which has been implicated in both cancer cell and normal cell survival.[22]
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.
.
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NeurodegenerationEGCG is a natural chelator and has been shown to reduce iron- accumulation in instances of neurodegenerative diseases like
dementia, Alzheimer's , and Parkinson's . [29] Parc de Salut Mar and Instituto Hospital del Mar de Investigaciones Médicas in Spain are conducting a clinical trial of EGCG as a potential treatment for intellectual impairment in people with Down Syndrome and Fragile X [30]
Drug interactionsA study using mouse models at the University of Southern California showed that, in contrast to the myriad benefits commonly associated with green tea and green tea extract (GTE), EGCG binds with the anti- cancer drug
Velcade, significantly reducing its bioavailability and thereby rendering it therapeutically useless.[33] Schönthal, who headed the study, suggests that
consumption of green tea and GTE products be strongly contraindicated for patients undergoing treatment for multiple myeloma and mantle cell lymphoma. [33] EGCG may reduce the bioavailability of the drug
sunitinib when they are taken together. [34] EGCG was also found to induce apoptosis in endometrial
carcinoma cell line (Ishikawa cells and human primary endometrial carcinoma cells) via ROS generation and p-38 activation.
http://en.m.wikipedia.org/wiki/Epigallocatechin_gallate