|
Ingredient Found in Green Tea
Provides Protection from Breast Cancer
Green tea is high in the antioxidant EGCG (epigallocatechin-3-
gallate) which helps prevent the body's cells from becoming damaged
and prematurely aged. Studies have suggested that the combination
of green tea and EGCG may also be beneficial by providing protection
against certain types of cancers, including breast cancer. A new
study conducted by researchers at the University of Mississippi
researchers now finds that consuming EGCG significantly inhibits
breast tumor growth in female mice. These results bring us one
step closer to better understanding the disease and potentially
new and naturally occurring therapies.
The study was conducted by Jian-Wei Gu, Emily Young, Jordan Covington,
James Wes Johnson, and Wei Tan, all of the Department of Physiology & Biophysics,
University of Mississippi Medical Center, Jackson, MS. Dr. Gu will
present his team's findings, entitled, Oral Administration of EGCG,
an Antioxidant Found in Green Tea, Inhibits Tumor Angiogenesis
and Growth of Breast Cancer in Female Mice, at the 121st Annual
Meeting of the American Physiological Society, part of the Experimental
Biology 2008 scientific conference.
Epidemiological studies suggest that green tea and its major
constituent, EGCG, can provide some protection against cancer.
Because these studies were very limited, the anti-cancer mechanism
of green tea and EGCG was not clear. As a result, the researchers
examined whether drinking EGCG (just the antioxidant infused in
water) inhibited the following: expression of VEGF (vascular endothelial
growth factor, which is found in a variety of breast cancer types);
tumor angiogenesis (thought to help tumors expand by supplying
them with nutrients); and the growth of breast cancer in female
mice.
Seven week old female mice were given EGCG (25 mg/50 ml) in drinking
water for five weeks (approximately 50-100 mg/kg/day.) The control
mice received regular drinking water. In the second week of the
study mouse breast cancer cells were injected in the left fourth
mammary glands of the mice. Tumor size was monitored by measuring
the tumor cross section area (TCSA). Tumors were eventually isolated
and measured for tumor weight, intratumoral microvessel (IM) density
(using staining), and VEGF protein levels (using ELISA).
At the end of the five week period the researchers found that
oral consumption of EGCG caused significant decreases in TCSA (66%),
tumor weight (68%), IM density 155±6 vs.111±20 IM#mm^2)
and VEGF protein levels (59.0±3.7 vs. 45.7±1.4 pg/mg)
in the breast tumors vs. the control mice, respectively (N=8; P<0.01).
Further, VEGF plasma levels were lower in EGCG mice than in control
mice (40.8±3.5 vs. 26.5±3.8 pg/ml P< 0.01).
Dr. Gu, the senior researcher for the study, hypothesized that
the reason for the link between EGCG and the reductions in the
cancer data was because EGCG directly targets both tumor blood
vessels and tumor cells of breast cancer for suppressing the new
blood vessels formation in breast tumor, the proliferation and
migration of breast cancer cells.
Gu concluded by saying, "In this study we have demonstrated
that the frequent ingestion of EGCG significantly inhibits breast
tumor growth, VEGF expression and tumor angiogenesis in mice. We
believe our findings will help lead to new therapies for the prevention
and treatment of breast cancer in women."
Nutritionhorizon.com
|
