The lab findings could offer a novel way to combat the HIV infection by preventing the virus from spreading
throughout the body, scientists said. Current treatments that target HIV fight
the infection after it has spread.
Scientists at the University of Tokyo, led by Kuzushige Kawai, found a
compound called epigallocatechin gallate or EGCG, the element believed to
contain most of the health benefits found in green tea, rapidly attaches to the
doorways that the AIDS virus uses to invade cells.
HIV prefers to infect cells called CD4 T-cells, and uses a molecular doorway
called the CD4 receptor to do so.
By bonding with the CD4 molecule first, EGCG effectively prevents the HIV
virus from attaching -- at least in lab dishes.
"This potentially opens up an avenue for preventing HIV infections," said Dr.
William Shearer, a professor at Baylor College of Medicine in Houston, who wrote
an editorial that accompanied the study. "Is there something here that mother
nature is trying to tell us?"
Writing in the Journal of Allergy and Clinical Immunology, the researchers
said they are still looking to explain why EGCG is attracted to CD4 molecule, in
the hope of making it work even better.
Earlier studies have showed that people who drink a lot of tea have lower
rates of cancer, heart disease and rheumatoid arthritis. In September, the U.S.
Department of Agriculture found people who drank black tea saw their
cholesterol drop between 7 and 11 percent.
Simply drinking tea would probably not be enough to prevent HIV infection,
Shearer said. If EGCG is shown to work in a living animal, it would have to be
concentrated, perhaps in a pill.
The lab study found that EGCG attached to 80 percent of CD4 receptors after
five minutes and to virtually all of them after 30 minutes.
The popularity of tea has soared during the last decade.
According to the Tea Association of the United States, total sales of tea in
2002 were $5.03 billion, up from $1.84 billion in 1990.
