A TRADITIONAL Indian remedy for lowering cholesterol really does work, and in a new way that might lead to the development of improved drugs, researchers said last week. The magical ingredient: the resin of the guggul tree. David Moore of the Baylor College of Medicine in Houston found the guggul extract lives up to its reputation. ‘‘It really does lower cholesterol in a number of clinical studies in Indian literature,’’ Moore said. Writing in the journal Science, he said it has been used in Ayurvedic medicine since at least 600 BC to treat obesity and other disorders.