Study finds that green tea blocks benefits of cancer drug

February 3, 2009

Contrary to popular assumptions about the health benefits of green tea, researchers at the University of Southern California (USC) have found that the widely used supplement renders a cancer drug used to treat multiple myeloma and mantle cell lymphoma completely ineffective in treating cancer.

The study, which found that a component of green tea extract (GTE) called EGCG destroys any anticancer activity of the drug Velcade in tumor-bearing mice, will be published in a future print edition of the journal, Blood. It is now available online at the journal's pre-publication First Edition website.

"Our finding that GTE or EGCG blocked the therapeutic action of Velcade was completely unexpected," says lead author Axel H. Schönthal, PhD, associate professor in the Department of Microbiology and Immunology at the Keck School of Medicine of USC. "Our hypothesis was that GTE or EGCG would enhance the anti-tumor effects of Velcade, and that a combination of GTE with Velcade (or EGCG with Velcade) would turn out to be a superior cancer treatment as compared to treatment with Velcade alone."

Herbal remedies, including green tea, have become a popular remedy for cancer patients dealing with side effects of chemotherapy. However, these supplements are unregulated and, for most, their beneficial and/or detrimental effects have not been qualified through research.

Using preclinical models and tumor-bearing mice, the researchers found that the unusually effective blockage of Velcade's therapeutic activity was based on the chemical interaction between molecules. The EGCG molecule and the Velcade molecule were able to form chemical bonds, meaning that the Velcade molecule could no longer bind to its intended target inside the tumor cells.

Clincal trials to verify these results in humans would be highly unethical to conduct, because of the predictably unfavorable outcome. Nevertheless, the researchers expect the results of the study to be applicable to cancer patients.

"The most immediate conclusion from our study is the strong advice that patients undergoing cancer therapy with Velcade must avoid green tea, and in particular all of its concentrated products that are freely available from health food stores," says Schönthal. "It is important to spread this message to health care providers who administer Velcade to patients."

Schönthal points out that for patients on Velcade, supplementing with green tea products should reduce the burden of harsh side effects—which might be attractive to the patient, but comes at a high cost.

"Essentially, in addition to not being able to attack tumor cells, Velcade would be unable to cause side effects either," he says. "As a result, the patient would feel a lot better and conclude that the consumption of GTE helped cope with side effects—while in reality, Velcade simply wasn't active in the first place."

The research findings are part of a larger project run by the team called "Yin-Yang Properties of Green Tea Extract in Combination Cancer Chemotherapy: From Encouragingly Beneficial to Dangerously Detrimental."

"Obviously, the combination of GTE or EGCG with Velcade is an example of 'dangerously detrimental,' "Schönthal says. "But we are also studying another well-established chemotherapeutic drug, where the inclusion of EGCG appears to yield an 'encouragingly beneficial' outcome, which is more in line with our original expectation that GTE should be beneficial, not detrimental."

More information: Encouse B. Golden, Philip Y. Lam, Adel Kardosh, Kevin J. Gaffney, Enrique Cadenas, Stan G. Louise, Nicos A. Petasis, Thomas C. Chen, Axel H. Schönthal. "Green Tea Polyphenols Block The Anticancer Effects of Bortezomib And Other Boronic Acid-Based Proteasome Inhibitors." Blood. bloodjournal.hematologylibrary.org/papbyrecent.dtl

Source: University of Southern California

Explore further: Mechanisms of action for green tea extract in breast cancer prevention identified

Related Stories

Mechanisms of action for green tea extract in breast cancer prevention identified

October 18, 2012
An oral green tea extract, Polyphenon E, appears to inhibit vascular endothelial growth factor and hepatocyte growth factor, both of which promote tumor cell growth, migration and invasion.

Study finds green tea reduces inflammation, may inhibit prostate cancer tumor growth

October 19, 2012
Men with prostate cancer who consumed green tea prior to undergoing prostatectomy had reductions in markers of inflammation, according to data presented at the 11th Annual AACR International Conference on Frontiers in Cancer ...

Green tea found to reduce rate of some GI cancers

October 31, 2012
Women who drink green tea may lower their risk of developing some digestive system cancers, especially cancers of the stomach/esophagus and colorectum, according to a study led by researchers from Vanderbilt-Ingram Cancer ...

Green tea compound shows promise for tackling cancer

August 22, 2012
A compound found in green tea could be a weapon in treatments for tackling cancer, according to newly-published research at the University of Strathclyde in Glasgow, Scotland.

Study explains how green tea could reduce pancreatic cancer risk

May 30, 2014
Green tea and its extracts have been widely touted as potential treatments for cancer, as well as several other diseases. But scientists have struggled to explain how the green tea and its extracts may work to reduce the ...

Researchers develop green tea-based 'missiles' to kill cancer cells more effectively

October 6, 2014
Green tea has long been known for its anti-oxidant, anti-cancer, anti-aging and anti-microbial properties. A group of researchers from the Institute of Bioengineering and Nanotechnology (IBN) of A*STAR has taken the health ...

Recommended for you

Childhood poverty, poor support may drive up pregnant woman's biological age

October 16, 2017
Pregnant women who had low socioeconomic status during childhood and who have poor family social support appear to prematurely age on a cellular level, potentially raising the risk for complications, a new study has found.

Chronic inflammation plays critical role in sustained delivery of new muscular dystrophy therapy

October 16, 2017
Macrophages, a type of white blood cell involved in inflammation, readily take up a newly approved medication for Duchenne muscular dystrophy (DMD) and promote its sustained delivery to regenerating muscle fibers long after ...

Worms reveal secrets of aging: Researchers discover a conserved pathway that controls aging

October 13, 2017
Investigators at Case Western Reserve University School of Medicine and University Hospitals Health System have identified a new molecular pathway that controls lifespan and healthspan in worms and mammals. In a Nature Communications ...

New study demonstrates importance of studying sleep and eating in tandem

October 13, 2017
A new study from scientists on the Florida campus of The Scripps Research Institute (TSRI) offers important insights into possible links between sleep and hunger—and the benefits of studying the two in tandem. A related ...

'Ridiculously healthy' elderly have the same gut microbiome as healthy 30 year-olds

October 11, 2017
In one of the largest microbiota studies conducted in humans, researchers at Western University, Lawson Health Research Institute and Tianyi Health Science Institute in Zhenjiang, Jiangsu, China have shown a potential link ...

A specific protein regulates the burning of body fat to generate heat

October 11, 2017
Scientists at the Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) have identified a protein that holds promise as a target for therapies to reduce obesity. Drs. Guadalupe Sabio and Nuria Matesanz have ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

brant
not rated yet Feb 03, 2009
What a load of crap. Implying that the cancer drug is better than Tea.
This article only applies to those who are having cancer treatment.

Not only that the success rate is little better than chance.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.