NEW YORK (Reuters Health) – Injection of a chemical found in green tea blocks the growth of bladder tumors in rats, according to a report published in the September issue of The Journal of Urology.

The chemical, called epigallocatechin-3-gallate (EGCG), has never been studied as an anti-cancer agent injected directly into the bladder, lead author Dr. J. Karl Kemberling and colleagues, from the Medical College of Ohio in Toledo, note.

Although EGCG has been shown to have anticancer properties, studies examining green tea use have yielded conflicting results. In one study, green tea consumption was actually tied to an increased risk of bladder cancer (see Reuters Health report November 26, 1999). However, in another study, drinking more than five cups per day seemed to protect against the malignancy.

In the new study, Kemberling’s team examined the anti-cancer effects of EGCG in the test tube and in rats with bladder tumors.

An EGCG dose was identified that could kill 100% of cancer cells after two hours of incubation.

The authors then tested EGCG on rats implanted with tumor cells. Thirty minutes after tumor cell injection, some of the animals were treated with EGCG, whereas others were not.

Eighteen of 28 animals (64 percent) treated with EGCG were tumor free three weeks later, the researchers note. In contrast, all 12 untreated animals showed tumor growth.

The results suggest that EGCG could be a useful treatment for bladder cancer. Moreover, “it is readily available and easily processed from green tea leaves,” the authors state.