Researcher’s work on green tea heating up

March 16, 2010 | Research, UToday



Two decades ago, most Americans were green when it came to green tea, in spite of its centuries-old reputation in China as a medicinal quaff. Today you can find even coffee devotees sipping Dragon Pearl and Chinese Gunpowder, lured by claims of antioxidant properties in the straw-colored brew.

Ahmed

Ahmed

More professional is the interest Dr. Salahuddin Ahmed, UT assistant professor of pharmacology, takes in the subject. For years, he’s been researching the potential of a green-tea compound called epigallocatechin 3-gallate (EGCG) in treating rheumatoid arthritis (RA).

“I developed the concept when I was a postdoctoral scientist at Case Western Reserve University,” he said. “We were working on this compound with a different form of arthritis — osteoarthritis — but the idea was to apply it to rheumatoid arthritis, a more aggressive and damaging type of disease.”

His team began receiving research funding during his subsequent move to the University of Michigan as a faculty member, when he developed a dual focus: green-tea extract that could be consumed as a dietary treatment and EGCG. “We also wanted to test this molecule the same way we’d test any other potential compound,” he said of the latter.

The need for rheumatoid arthritis treatment is real. A disease of the dysregulated immune system, RA can be traced to genetic or environmental factors, or a combination of both. Once triggered, the disease signals the body’s immune system to secrete cytokines — signaling molecules essential to cell-to-cell communication.

So far, so good, Ahmed said. “But things get out of hand and the synthesis of the inflammatory cytokines and their byproducts in turn activates other cellular components of the joint, including cartilage and bone cells.” The resulting bone destruction can begin within two years of RA’s initial symptoms.

Using cultured synovial fibroblast cells isolated from RA patients, Ahmed’s research team treated some with EGCG, leaving others untreated. Their observation showed that the molecule inhibited certain inflammatory chemicals associated with rheumatoid arthritis. When they used their highest dose, in fact, production of the inflammatories all but ceased.

If early results continue to develop toward a form of treatment, it could mean better life expectancy for rheumatoid arthritis patients. “People with RA tend to die early because the result of having so much systemic inflammation is that it leaks from the joint and into the blood,” Ahmed explained. “All the reactive proteins and cytokines keep circulating in the body, where they can affect the cardiovascular system.” Most RA patients die of cardiovascular complications, with studies suggesting that the lifespan can be reduced by as much as 10 years.

“We hope to address that bridge as well,” Ahmed added of his ongoing work.

While it’s too early to prescribe either green-tea extract or EGCG as a specific rheumatoid arthritis treatment, he calls the results in the experimental systems and animal models of human RA very promising.

In the meantime, green tea will continue to be popular; most researchers agree that it has health benefits and no serious side effects.