MONDAY, Feb. 25, 2002 (HealthDayNews) -- You take aspirin for aches and pains and to prevent heart attacks, but the little white pill may also help keep your immune system solid.
A new study says aspirin and related painkillers may block the replication of a common virus linked to birth defects and potentially deadly infections in people with AIDS and other immune disorders.
The presence of the microbe, called human cytomegalovirus (HCMV), in cells is accompanied by a surge of prostaglandins, chemicals in the body that promote pain, inflammation and fever. So, scientists wondered if they could keep HCMV from replicating by denying them access to these molecules.
Suppressing prostaglandins is easy. That's what so-called painkillers do. Aspirin and related drugs, like cox-2 inhibitors -- most often used to treat arthritis -- clamp down on the chemicals by blocking the production of cyclooxygenase, the enzyme that urges cells to produce prostaglandins.
In the latest study, which appears in tomorrow's issue of the Proceedings of the National Academy of Sciences, Thomas Shenk, a molecular biologist at Princeton University, and his colleagues tried to prevent HCMV replication in human connective tissue cells in a dish by dosing them with a cox-2 inhibitor (an experimental drug being developed by Bristol-Myers Squibb). Other cox-2 pills already on the market include Merck's Vioxx and Celebrex, from Pharmacia Corp.'s Searle division.
When infected with the virus -- a member of the herpes family -- the fibroblast cells temporarily boosted their production of prostaglandin E2 more than 50-fold. But when treated with the cox-2 inhibitor, the number of virus copies in the cell fell more than 100-fold.
"There's a significant block there in the virus production," says Hua Zhu, a molecular geneticist at New Jersey Medical School in Newark and lead author of the study.
To prove prostaglandin E2 was the key to this effect, Shenk's group added the molecule to infected cells treated with the cox-2 drug. This time, the virus reproduced with little problem.
The researchers don't know why HCMV needs prostaglandin E2, or other chemicals in that family. Nor, says Zhu, do they know if the same experiment would work in people. However, at least one study in mice has shown certain virus replication is slowed by feeding the animals aspirin.
Dr. Stephen Prescott, a cox-2 expert at the Huntsman Cancer Institute in Salt Lake City, says that while he's not familiar with the latest work, it makes sense biologically.
Prostaglandins are known to control the reading, or transcription, of genes in cell nuclei in at least two ways, he explains, and viruses depend on this process to replicate. So muzzling the production of these chemicals could make life difficult for the microbes. But whether that is what the latest study describes, "I have no direct evidence," he says.
What To Do
For more on how aspirin works, try the Aspirin Foundation of America.
For more on cytomegalovirus, visit the The Body, and HIV/AIDS information resource, or the Centers for Disease Control and Prevention.
