A plant used by Native Americans to treat everything from STDs to the common cold may offer hope for AIDS. Dr. Fu Chih Huang, a biology professor at Johns Hopkins University in Baltimore, is studying the AIDS-fighting potential of the creosote bush (chaparral), which grows wild in the deserts of the Southwest and Mexico. Huang discovered that a molecule found in a chemical compound in the plant halted replication of HIV as well as herpes. Her curiosity was piqued after she heard about creosote's folkloric reputation among Native Americans, who boil the leaves and branches to make a lineament for bruises and rheumatism, and a tonic for stomach trouble and diarrhea.

But most health-food stores stopped selling chaparral in 1992, after an FDA warning that the capsule form was linked to six cases of acute toxic hepatitis. Though chaparral is still sold by mail order, Huang cautions against self-prescribing it. But according to Kenneth DeBoer of Western Biotech Inc., his company's new leaf-resin concentrate called Larreastat, has improved chaparral's safety and efficacy.