Drug leads from the Kallawaya herbalists of Bolivia. 1. Background, rationale, protocol and anti-HIV activity.

Aqueous, organic and alcoholic extracts of over 100 samples of 60 species of Kallawaya medicinal herbs representing 30 plant families were assayed to compare their toxicity and ability to protect MT-2 T-lymphoblastoid cells from the cytopathic effect of human immunodeficiency virus (HIV). The results are reported as a therapeutic index (TI) which was > 25 for eighteen species, including seven > 50 and one > 100. The anti-HIV activity resided primarily in the aqueous rather than in the organic extracts and was concentrated in plants used in ethnomedicine to treat lung and liver diseases.