Epigallocatechin gallate
Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the most abundant catechin in tea and is found in higher concentrations in green tea compared to white and black tea. [1]
EGCG's effects on EMMPRIN/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[2]. EMMPRIN/CD147 induces the production of matrix metalloproteinases (MMP) such as MMP-9 and MMP-2.[3][4]
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.[6] EGCG is notorious for its low bioavailability[7], 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[8]). 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/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]
EGCG doses <800mg/day have not shown any hepatotoxic effects according to the European Food Safety Authority.[11]
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[12], meaning EGCG might have 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.[13] 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.
- ↑ "Epigallocatechin gallate". Wikipedia. April 25, 2020.
- ↑ "Basigin". Wikipedia. April 15, 2020.
- ↑ Jouneau, Stephane; Khorasani, Nadia; DE Souza, Patricia; Macedo, Patricia; Zhu, Jie; Bhavsar, Pankaj K.; Chung, Kian F. (2011-05). "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. Check date values in:
|date=(help) - ↑ Zhang, Z.; Yang, X.; Zhang, H.; Liu, X.; Pan, S.; Li, C. (2018-06). "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. Check date values in:
|date=(help) - ↑ 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.
- ↑ 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.
- ↑ Frank, Kurtis; Patel, Kamal; Lopez, Gregory; Willis, Bill (February 21, 2020). "Green Tea Catechins Research Analysis". Cite journal requires
|journal=(help) - ↑ Frank, Kurtis; Patel, Kamal; Lopez, Gregory; Willis, Bill (February 21, 2020). "Green Tea Catechins Research Analysis". Cite journal requires
|journal=(help) - ↑ Nair, Anroop B.; Jacob, Shery (2016-3). "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. Check date values in:
|date=(help) - ↑ 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.
- ↑ 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.
- ↑ 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.
- ↑ 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.
