NEW YORK, Feb 18 (Reuters Health) -- Synthetic versions of chemicals extracted from plants used by Bolivian shamans to treat various illnesses appear to inhibit the ability of HIV to infect healthy cells in laboratory testing, according to researchers at the University of California at Irvine. If found to be effective in humans, these chemicals could one day be developed into drugs used to fight AIDS.
Several years ago, Dr. Joseph Bastien, an anthropology professor at the University of Texas at Arlington, brought back 60 of some 900 plants that Kallawaya shamans in Bolivia have used for centuries to treat disease.
Dr. Manfred Reinecke, professor of chemistry at Texas Christian University in Fort Worth, made extracts of the plants and tested them for chemical activity against a variety of diseases, including infections such as malaria.
At the same time, Dr. W. Edward Robinson, Jr., associate professor of pathology and microbiology at the University of California at Irvine, and colleagues began testing the same extracts against the AIDS virus. From the most promising extracts, Robinson created seven synthetic chemicals, called analogues, that appear to inhibit HIV by acting against the HIV enzyme integrase. Integrase helps AIDS to spread by integrating the infectious virus into the DNA of healthy cells.
Anti-AIDS cocktails now prescribed to patients target the other two enzymes, HIV protease and HIV reverse transcriptase, but a successful drug to combat the integrase enzyme has eluded researchers.
In an interview with Reuters Health, Robinson said he is still tinkering with the synthetic chemicals to try to improve them, but he anticipates that clinical trials could begin in humans in about 2 years. "We'd like to see them added to the current drug cocktails that inhibit HIV protease and HIV reverse transcriptase to see if patients do better with a compound that also fights HIV integrase," he said.
Unlike the chemical cocktails currently used by AIDS patients, the analogues that battle HIV integrase do not appear to be toxic to cells and may therefore be better tolerated.
Nearly one third of the drugs available today are extracts from plants, including aspirin, which originated from the bark of the willow tree. Some of Robinson's chemical compounds are based on plant extracts from the chicory herb.
SOURCE: Journal of Medicinal Chemistry February 11,1999.
