Green Tea Helps Fight Cancer!

Green tea extract shows promise as an anti-cancer agent, UCLA study finds

Jonsson Cancer Center researchers find green tea may help fight bladder cancer.
A study on bladder cancer cells lines showed that green tea extract has potential as an anti-cancer agent, proving for the first time that it is able to target cancer cells while leaving healthy cells alone.

The study, published in the Feb. 15, 2005 issue of the peer-reviewed journal Clinical Cancer Research, also uncovered more about how green tea extract works to counteract the development of cancer, said JianYu Rao, a Jonsson Cancer Center member, an associate professor of pathology and laboratory medicine and the study's senior author.

"Our study adds a new dimension in understanding the mechanisms of green tea extract," Rao said. "If we knew exactly how it works to inhibit the development of cancer, we could figure out more precisely which bladder cancer patients might benefit from taking it."

Numerous epidemiologic and animal studies have suggested that green tea extract provides strong anti-cancer effects in several human cancers, including bladder cancer. It has been shown to induce death in cancer cells, as well as inhibiting the development of an independent blood supply that cancers develop so they can grow and spread.

In the UCLA study, which brought together researchers from UCLA's Jonsson Cancer Center, School of Public Health, Center for Human Nutrition and the departments of Pathology and Laboratory Medicine, Surgery, Urology and Epidemiology, scientists were able to show that green tea extract interrupts a process that is crucial in allowing bladder cancer to become invasive and spread to other areas of the body.

Green tea extract affects actin remodeling, an event associated with cell movement. When a human moves, the muscles and skeletal structure operate together to facilitate that movement.

For cancer to grow and spread, the malignant cells must be able to move. The cell movement depends on actin remodeling, which is carefully regulated by complex signaling pathways, including the Rho pathway. When actin remodeling is activated, the cancer cells can move and invade other healthy cells and eventually other organs.

By inducing Rho signaling, the green tea extract made the cancer cells more mature and made them bind together more closely - a process called cell adhesion. Both the maturity of the cells and the adhesion inhibited the mobility of the cancer cells, Rao said.

"In effect, the green tea extract may keep the cancer cells confined and localized, where they are easier to treat and the prognosis is better," Rao said. "Cancer cells are invasive and green tea extract interrupts the invasive process of the cancer."
Bladder cancer is the fifth most common cancer in the United States, with about 56,000 new cases diagnosed each year. About half of all bladder cancers are believed to be related to cigarette smoking. Without a reliable, non-invasive way to diagnose the disease, bladder cancer can be difficult to detect in the early, most treatable stages. When not found early, the tumors can be aggressive, and more than half of patients with advanced cancers experience recurrences.

Rao cautioned that his study was conducted in a carefully controlled cell line environment and that more research needs to be done to discover exactly how green tea extract functions as a cancer fighter. The next phase of his research will analyze urine from bladder cancer patients to determine which subset of patients would benefit most from taking green tea extract. Researchers will be looking for specific biomarkers associated with actin remodeling and activation of the Rho signaling pathway.

"We're hoping the results from these studies will tell us who will best benefit from the agent," Rao said, adding that the basic research he is doing and the clinical trial on bladder cancer patients will provide scientists with vital information from both ends the research continuum, an example of bench-to-bedside-and-back-again science.

"I think this publication further supports the potential role of green tea in the prevention and treatment of bladder cancer," said Dr. Robert Figlin, a UCLA professor of hematology/oncology and urology and a principal investigator for the human studies. "In the end, both studies will help us achieve our goal - to decrease bladder cancer occurrence and develop molecular profiles that tell us who is most at risk."

Green Tea Extract  
Green tea is a potent cancer-fighter. It is a known fact that people who drink green tea are less likely to develop cancer. A new study indicates green tea's ability to fight cancer is even more potent and varied than scientists have suspected.
Researchers say they've discovered chemicals in green tea that shut down one of the key molecules that tobacco relies upon to cause cancer. The finding by scientists at the University of Rochester's Environmental Health Science Center appears in the journal Chemical Research in Toxicology, published by the American Chemical Society.

Green Tea Extract contains 75% polyphenols - the substances that support healthy cholesterol levels and efficient fat metabolism. Of further benefit, polyphenols exert a strong antioxidant reaction, scavenging for free radicals that can damage cells.
Evidence of green tea's health-promoting benefits came from the Japanese culture. The Japanese have the lowest level of heart disease and highest longevity rate of all industrialized nations. Although many aspects contribute to the Japanese low-disease rate, green tea is thought to be an important element.
 
-    Top antioxidant in Asia.
-    Equivalent to 12 cups of tea in convenient capsule delivery
-    Supports healthy cholesterol levels
-    Fights free radicals

The three basic tea types come from the evergreen shrub Camellia sinensis. Black, green, and oolong teas are produced from the tea plant by varying the processing conditions. Black tea is produced by fermenting the leaves, while green tea leaves are not fermented. Oolong teas go through a shorter fermentation period than black teas and are regarded as semi-fermented. All three kinds go through a heating process to halt fermentation.

Although most people drink black tea (made from fermented leaves), about a quarter of all tea consumed is green (unfermented). All teas from Camellia sinensis contain compounds known as polyphenols -- a class of bioflavonoids -- which are found in all plants. Polyphenols have anti-cancer, antioxidant, anti-bacterial, and anti-viral properties. Besides tea, these compounds are especially high in coffee, red grapes, kidney beans, raisins, prunes, and red wine.

Purdue University (West Lafayette, Ind.) researchers Dorothy Morre and D. James Morre reported in December 1998 at the 38th annual meeting of the American Society for Cell Biology in San Francisco, that EGCG inhibits an enzyme called NOX. This enzyme helps carry out several cell functions and is required for growth in both normal and cancerous cells. The overactive and cancer-causing form of NOX is known as tNOX.

"Our research shows that green tea leaves are rich in this anti-cancer
compound, with concentrations high enough to induce anti-cancer effects
in the body," Dorothy Morre, professor of foods and nutrition in
Purdue's School of Consumer and Family Sciences, tells WebMD.

"Drinking more than four cups of green tea a day," she says, "could
provide enough of the active compound to slow and prevent the growth of
cancer cells.