A search for anti-viral properties in Panamanian medicinal plants. The effects on HIV and its essential enzymes

Aqueous and methanolic extracts of 39 Panamanian medicinal plants were test ed for anti-human immunodeficiency virus (HIV) effects. The extracts were t ested for the inhibition of HIV-induced cytopathic effects in cultured cell s, HIV-reverse transcriptase (RT) and HIV-protease (PR) enzymes. The water extract of the branches of Jatropha curcas (Euphorbiaceae) inhibited strong ly the HIV-induced cytopathic effects with low cytotoxicity. On the other h and, the water extracts of the whole plant of Chamaesyce hyssopifolia (Euph orbiaceae), the leaves of Cordia spinescens (Boraginaceae) and the aerial p arts of Hyptis lantanifolia (Labiatae), and the methanol extract of the aer ial parts of Tetrapteris macrocarpa (Malpighiaceae) were potent inhibitors of HIV-RT (IC50: 6-8 mu g/ml). Seven out of 39 plants were found to be mode rate inhibitors of HIV-PR (IC50: 43-100 mu g/ml). Furthermore, we report on the respective inhibitory substances of J. curcas, C. hyssopifolia and C. spinescens, and their possible mechanism of action. (C) 1999 Elsevier Scien ce Ireland Ltd. All rights reserved.