Tag Archives: green tea

How green tea could help treat bone marrow disorders

Published / by Beth / 2 Comments on How green tea could help treat bone marrow disorders

http://www.futurity.org/amyloidosis-green-tea-1356282-2/

Jan Bieschke of Washington University in St. Louis studies how proteins fold and shape themselves, and how these processes can contribute to a variety of diseases. He says the compound epigallocatechine-3-gallate (EGCG), a polyphenol found in green tea leaves, may be of particular benefit to patients struggling with multiple myeloma and amyloidosis.

These patients are susceptible to a frequently fatal condition called light chain amyloidosis, in which parts of the body’s own antibodies become misshapen and can accumulate in various organs, including the heart and kidneys.

“The idea here is twofold: We wanted to better understand how light chain amyloidosis works, and how the green tea compound affects this specific protein,” says Bieschke, assistant professor of biomedical engineering at the School of Engineering & Applied Science.

Bieschke’s team first isolated individual light chains from nine patients with bone marrow disorders that caused multiple myeloma or amyloidosis, then ran lab experiments to determine how the green tea compound affected the light chain protein.

“We all want this compound to work in a patient.”

Bieschke previously examined EGCG’s effect in both Parkinson’s and Alzheimer’s disease, and found it prevented dangerous buildups of protein present in both diseases. His team had a similar conclusion in this study: In the lab using samples from bone marrow patients, the EGCG transformed light chain amyloid, preventing the misshapen form from replicating and accumulating dangerously.

“In the presence of green tea, the chains have a different internal structure,” Bieschke says. “The ECGC pulled the light chain into a different type of aggregate that wasn’t toxic and didn’t form fibril structures,” as happens to organs affected by amyloidosis.

Why kale and green tea could be a bad combo

While Bieschke is gaining a greater understanding at the intracellular processes involved, his partners at the University of Heidelberg are working in tandem with him, running clinical trials.

“My group is looking at the mechanism of the protein in a test tube; we are studying how it works on a foundational level. At the same time, clinical trials at the Amyloidosis Center in Heidelberg, with Alzheimer’s in Berlin and with Parkinson’s in China examine the process in people. We all want this compound to work in a patient.”

The research appears in the Journal of Biological Chemistry.

Source: Washington University in St. Louis

Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors

Published / by Beth / 2 Comments on Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors

This caught my eye because I’ve been on Velcade before and never gave a second thought to whether or not I should not be consuming green tea/green tea products.

Blood First Edition Paper, prepublished online February 3, 2009; DOI 10.1182/blood-2008-07-171389.

Submitted July 28, 2008
Accepted January 12, 2009

Encouse B. Golden, Philip Y. Lam, Adel Kardosh, Kevin J. Gaffney, Enrique Cadenas, Stan G. Louie, Nicos A. Petasis, Thomas C. Chen, and Axel H. Schonthal*

Department of Pathology, University of Southern California (USC) Keck School of Medicine (KSOM), Los Angeles, CA, United States
Department of Molecular Pharmacology and Toxicology, USC School of Pharmacy (SoP), Los Angeles, CA, United States
Department of Molecular Microbiology and Immunology, USC KSOM, Los Angeles, CA, United States
Department of Chemistry, USC College of Letters, Arts and Sciences, Los Angeles, CA, United States
Department of Clinical Pharmacy and Pharmaceutical Economics and Policy, USC SoP, Los Angeles, CA, United States
Department of Neurosurgery, USC KSOM, Los Angeles, CA, United States

* Corresponding author; email: schontha@usc.edu.

The anticancer potency of green tea and its individual components is being intensely investigated, and some cancer patients already self-medicate with this ‘miracle herb’ in hopes of augmenting the anticancer outcome of their chemotherapy. Bortezomib (Velcade®) is a proteasome inhibitor in clinical use for multiple myeloma. Here, we investigated whether the combination of these compounds would yield increased antitumor efficacy in multiple myeloma and glioblastoma cell lines in vitro and in vivo. Unexpectedly, we discovered that various green tea constituents, in particular (-)-epigallocatechin gallate (EGCG) and other polyphenols with 1,2-benzenediol moieties, effectively prevented tumor cell death induced by bortezomib in vitro and in vivo. This pronounced antagonistic function of EGCG was only evident with boronic acid-based proteasome inhibitors (bortezomib, MG-262, PS-IX), but not with several non-boronic acid proteasome inhibitors (MG-132, PS-I, nelfinavir). EGCG directly reacted with bortezomib and blocked its proteasome inhibitory function; as a consequence, bortezomib could not trigger endoplasmic reticulum stress or caspase-7 activation, and did not induce tumor cell death. Taken together, our results indicate that green tea polyphenols may have the potential to negate the therapeutic efficacy of bortezomib and suggest that consumption of green tea products may be contraindicated during cancer therapy with bortezomib.