In vitro antileishmanial and antimalarial activities of tetrahydrofuran lignans isolated from Nectandra megapotamica (Lauraceae)

Abstract

Seven tetrahydrofuran lignans, isolated from Nectandra megapotamica (Lauraceae), were evaluated for their in vitro antileishmanial and antimalarial activities. Among the evaluated compounds, machilin-G (1a) and veraguensin (2a) showed the highest antileishmanial activities, displaying for both compounds an IC₅₀ value of 18 µg/mL and an IC₉₀ value of 36 µg/mL, while galgravin (1b), nectandrin-A (1c), nectandrin-B (1d), calopeptin (2b) and ganshisandrine (3) were inactive against Leishmania donovani. In the antimalarial assay against Plasmodium falciparum, it was observed that calopeptin (2b) displayed moderate activity, with IC₅₀ values of 3800 ng/mL (D6 clone) and 3900 ng/mL (W2 clone), while the lignans 1a–1d, 2a and 3 were inactive. In order to compare the effect on the parasites with toxicity to mammalian cells, the cytotoxic activity of the isolated compounds were evaluated against the Vero cells, showing that all evaluated tetrahydrofuran lignans exhibited no cytotoxicity at the maximum dose tested. Copyright © 2008 John Wiley & Sons, Ltd.