Green tea as a therapeutic agent in endometriosis

Some components of green tea are shown to have favorable effects on endometriosis lesions

Key Points

Highlight

• Epigallocatechin gallate (EGCG), one of the main polyphenol catechins found in green tea has anti-oxidant, anti-angiogenetic, anti-proliferative effects in endometriotic tissue.

Importance

• With many alternative treatment methods that aim to reduce the symptoms of the disease new therapeutic agents that target its proliferation are needed.
• Green tea has provided good results with its many effects on different phases of endometriosis progression and might be a candidate for its management.  

Key results

• EGCG has anti-oxidant effects which result in reducing the production of reactive oxygen species which then decreases the proliferation of lesions.
• The anti-angiogenetic effect which mainly happens through the inhibition of VEGF expression is the biggest contributor to its anti-cancer properties.
• It activates p53 and promotes apoptosis of the tumor cells selectively.
• It binds to estrogen receptors and inhibits the proliferative effects of E2 on endometrial cells.
• Its anti-inflammatory effects occur via the targeting of arachidonic acid metabolism from many levels.  

What’s done here

• This is a review of the studies that investigated the effects of green tea, in particular, its effective content EGCG on molecular and cellular levels with the aim of finding a potential treatment method for endometriosis.
• Researchers evaluated all the characteristics of EGCG on different phases of disease progression by providing detailed studies on the subject.

Lay Summary

Tea is among the most consumed beverages all around the world. It has many kinds which originate from the same plant “Camellia sinensis” but differ in color after the fermentation process. Green tea is the one produced right after the harvest without fermentation and is known to contain multiple beneficial ingredients such as catechins, amino acids, caffeine, and vitamins. Catechins are the main anti-oxidant agents found in green tea and they have a role in neutralizing reactive oxygen species. Epigallocatechin gallate (EGCG) is the most abundant catechin with its important anti-inflammatory, anticancer and anti-angiogenic potential.

There are many studies aiming to prove the different beneficial effects of green tea on human health. Researchers from China and Hong Kong have written a review on different molecular and cellular mechanisms of the contents of green tea on prohibiting inflammation, oxidative stress, invasion, and angiogenesis and its potential to be used particularly in endometriosis. It was published in a recent issue of the journal "Critical Reviews in Food Science and Nutrition".

Anti-oxidant effects of EGCG have been studied extensively and anti-proliferative properties seem to be ascribable to these effects. In mouse study, it was shown to inhibit the proliferation of endometriotic lesions. EGCG inhibits angiogenic MMP-2 and reduces endothelial proliferation, also activates p53 to promote apoptosis. The inhibition of TGF-β1 and E-cadherin causes less adhesiveness and fibrosis.

The anti-inflammatory effects of tea polyphenols are also attributed to the reduction of endometriotic lesions by targeting arachidonic acid pathways. One of the biggest anti-cancer effects of green tea occurs via anti-angiogenesis with EGCG inhibiting endothelial cell growth through decreased VEGF expression. In endometrial cells, estrogen is blocked by EGCG by competitively binding to estrogen receptors and suppresses the development of endometriotic lesions.

The authors also emphasize the possible side effects of the overconsumption of green tea. These are mostly caused by the caffeine and the aluminum it contains and the binding of the iron. Another study by the authors with a synthetic variant of EGCG which aims to use it as a pro-drug is also mentioned. It is concluded that more extensive studies and clinical trials with endometriosis patients are needed to prove the effects of green tea on the disease and its usage as a therapeutic agent.

Research Source: https://pubmed.ncbi.nlm.nih.gov/34620005/