In Vitro Atileishmanial and Cytotoxic Activities of Annona mucosa (Annonaceae)

The antileishmanial activity of extracts from the leaves and seeds of Annona mucosa, and of the oxoaporphine alkaloid liriodenine isolated from the dichloromethane extract of the leaves, were evaluated in vitro against promastigote forms of three Leishmania species and against intracellular amastigote forms of L. amazonensis. Cytotoxic activity was evaluated against peritoneal macrophages of mice. The dichloromethane extract from the leaves was the most active against Leishmania spp., showing IC50 values lower than 30 mu g.mL(-1) . Liriodenine was the most cytotoxic against peritoneal macrophages. Hexane extracts of seeds showed the highest selectivity index against Leishmania spp. (SI = 5.93 to 1.54). All samples were active against intracellular amastigote forms, after 96 h inhibiting more than 70% of amastigote replication in infected macrophages. Phytochemical investigation of the dichloromethane extract from the leaves of A. mucosa led to the isolation of the oxoaporphine alkaloids atherospermidine (1) and liriodenine (2), identified on the basis of their spectroscopic data, mainly 1D/2D NMR, and comparison with literature data.