Epigallocatechin gallate

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Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is an antioxidant and flavonoid, and is the most abundant catechin in tea.[1][2] EGCG is found in higher concentrations in green tea compared to white and black tea.[3] One cup of camellia sinensis green tea contains approximately 50mg of EGCG-equivalent.[4]

Theory[edit | edit source]

Evidence[edit | edit source]

EGCG's effects on CD147 & collagen degrading enzymes[edit | edit source]

There's a receptor in the body called CD147. This receptor is also called "extracellular matrix metalloproteinase inducer" (EMMPRIN) or Basigin.[5] EMMPRIN/CD147 induces the production of matrix metalloproteinases (MMP) such as MMP-9 and MMP-2.[6][7]

EGCG have been shown to inhibit the expression of EMMPRIN and MMP-9 in an in vitro study.[5] In a mouse study intraperitoneally injected EGCG was found to decrease the expression levels of MMP-2, MMP-9, and EMMPRIN.[8] EGCG is notorious for its low bioavailability,[4] which could mean the studies above aren't applicable for normal oral dosages. However, this doesn't seem to be the case.

In a rat study, 20 mg EGCG per day was administered orally in the context of abdominal aortic aneurysm (rats seems to have the same low absorption of EGCG as humans).[4] The study found that the EGCG lowered the gene expression levels of inflammatory cytokines (TNF-a & IL-1b), promoted elastoregeneration (regeneration of elastin, an important component of connective tissue) and lowered the gelatinolytic activity of MMP-9 with 63%. The dosage was the equivalent of 0.04 mg EGCG/g body weight/day. If you convert that to a human dose (0,04/6,2[9]= 0,006452mg/g human dose = 6.452 mg/kg human dose) it translates to 452 mg oral EGCG per day for someone who weighs 70kg.

In a human study, breast cancer patients undergoing radiotherapy ingested 400 mg oral EGCG x3 / day for several weeks. The levels of serum active MMP-9 decreased by an average of 31% at week 2 and 55% at week 8. The levels of serum MMP-2 zymogens decreased by an average of 22% at week 2 and 51% at week 8.[10]

SARS-CoV-2 & CD147[edit | edit source]

The SARS-CoV-2 virus can invade host cells not only via the ACE2 receptor, but also via the CD147/EMMPRIN receptor,[11] meaning EGCG may have beneficial effects in the context COVID-19. EGCG have also been shown to have antifibrotic effects in a human study testing 600 mg oral EGCG/day in patients with pulmonary fibrosis undergoing lung biopsy.[12] This mean that EGCG, apart from potentially having an antiviral effect against the SARS-CoV-2 virus, might reduce the risk of lung scarring from COVID-19.

Fatigue[edit | edit source]

Experiments on severely fatigue rats with exercise-induced fatigue found that ECGC led to an improvement in symptoms.[2]

ME/CFS[edit | edit source]

There is a lack of evidence about the use of ECGC in people with ME/CFS.

Risks and safety[edit | edit source]

EGCG doses of below 800mg per day have not shown any hepatotoxic effects according to the European Food Safety Authority.[13]

Costs and availability[edit | edit source]

Inexpensive and available over the counter as a supplement, or can be consumed in strong tea. ECGC is sometimes sold as in supplements containing caffeine or other nutrients, fur example SLIMQUICK. [1]

See also[edit | edit source]

Learn more[edit | edit source]

References[edit | edit source]

  1. 1.01.1 PubChem. "(-)-Epigallocatechin gallate". pubchem.ncbi.nlm.nih.gov. Retrieved March 7, 2021.
  2. 2.02.1 Singh, Amanpreet; Naidu, Pattipati S.; Gupta, Saraswati; Kulkarni, Shrinivas K. (2002). "Effect of natural and synthetic antioxidants in a mouse model of chronic fatigue syndrome". Journal of Medicinal Food. 5 (4): 211–220. doi:10.1089/109662002763003366. ISSN 1096-620X. PMID 12639396.
  3. Lee, Ki Won; Lee, Hyong Joo; Lee, Chang Yong (April 2002). "Antioxidant activity of black tea vs. green tea" (PDF). The Journal of Nutrition. 132 (4): 785, author reply 786. doi:10.1093/jn/132.4.785. ISSN 0022-3166. PMID 11925478.
  4. 4.04.14.2 Frank, Kurtis; Patel, Kamal; Lopez, Gregory; Willis, Bill (February 21, 2020). "Green Tea Catechins Research Analysis".
  5. 5.05.1 Wang, Qi-Ming; Wang, Hao; Li, Ya-Fei; Xie, Zhi-Yong; Ma, Yao; Yan, Jian-Jun; Gao, Yi Fan Wei; Wang, Ze-Mu; Wang, Lian-Sheng (2016). "Inhibition of EMMPRIN and MMP-9 Expression by Epigallocatechin-3-Gallate through 67-kDa Laminin Receptor in PMA-Induced Macrophages". Cellular Physiology and Biochemistry. 39 (6): 2308–2319. doi:10.1159/000447923. ISSN 1015-8987. PMID 27832636.
  6. Jouneau, Stephane; Khorasani, Nadia; DE Souza, Patricia; Macedo, Patricia; Zhu, Jie; Bhavsar, Pankaj K.; Chung, Kian F. (May 2011). "EMMPRIN (CD147) regulation of MMP-9 in bronchial epithelial cells in COPD". Respirology (Carlton, Vic.). 16 (4): 705–712. doi:10.1111/j.1440-1843.2011.01960.x. ISSN 1440-1843. PMID 21355964.
  7. Zhang, Z.; Yang, X.; Zhang, H.; Liu, X.; Pan, S.; Li, C. (June 2018). "The role of extracellular matrix metalloproteinase inducer glycosylation in regulating matrix metalloproteinases in periodontitis". Journal of Periodontal Research. 53 (3): 391–402. doi:10.1111/jre.12524. ISSN 1600-0765. PMID 29315565.
  8. Wang, Qiming; Zhang, Jian; Li, Yafei; Shi, Haojie; Wang, Hao; Chen, Bingrui; Wang, Fang; Wang, Zemu; Yang, Zhijian (2018). "Green tea polyphenol epigallocatechin-3-gallate increases atherosclerotic plaque stability in apolipoprotein E-deficient mice fed a high-fat diet". Kardiologia Polska. 76 (8): 1263–1270. doi:10.5603/KP.a2018.0114. ISSN 1897-4279. PMID 29862488.
  9. Nair, Anroop B.; Jacob, Shery (March 2016). "A simple practice guide for dose conversion between animals and human". Journal of Basic and Clinical Pharmacy. 7 (2): 27–31. doi:10.4103/0976-0105.177703. ISSN 0976-0105. PMC 4804402. PMID 27057123.
  10. Zhang, G.; Wang, Y.; Zhang, Y.; Wan, X.; Li, J.; Liu, K.; Wang, F.; Liu, Q.; Yang, C. (January 31, 2012). "Anti-Cancer Activities of Tea Epigallocatechin-3-Gallate in Breast Cancer Patients under Radiotherapy". Current Molecular Medicine. doi:10.2174/156652412798889063. Retrieved April 27, 2020.
  11. Wang, Ke; Chen, Wei; Zhou, Yu-Sen; Lian, Jian-Qi; Zhang, Zheng; Du, Peng; Gong, Li; Zhang, Yang; Cui, Hong-Yong (March 14, 2020). "SARS-CoV-2 invades host cells via a novel route: CD147-spike protein". bioRxiv: 2020.03.14.988345. doi:10.1101/2020.03.14.988345.
  12. Chapman, Harold A.; Wei, Ying; Montas, Genevieve; Leong, Darren; Golden, Jeffrey A.; Trinh, Binh N.; Wolters, Paul J.; Le Saux, Claude J.; Jones, Kirk D. (March 12, 2020). "Reversal of TGFβ1-Driven Profibrotic State in Patients with Pulmonary Fibrosis". New England Journal of Medicine. 382 (11): 1068–1070. doi:10.1056/NEJMc1915189. ISSN 0028-4793. PMID 32160670.
  13. Younes, Maged; Aggett, Peter; Aguilar, Fernando; Crebelli, Riccardo; Dusemund, Birgit; Filipič, Metka; Frutos, Maria Jose; Galtier, Pierre; Gott, David (2018). "Scientific opinion on the safety of green tea catechins". EFSA Journal. 16 (4): e05239. doi:10.2903/j.efsa.2018.5239. ISSN 1831-4732.

enzyme a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.

cytokine any class of immunoregulatory proteins secreted by cells, especially immune cells. Cytokines are small proteins important in cell signaling that modulate the immune system. (Learn more: me-pedia.org)

serum The clear yellowish fluid that remains from blood plasma after clotting factors have been removed by clot formation. (Blood plasma is simply blood that has had its blood cells removed.)

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From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history.