Antileishmanial, Antimalarial and Antimicrobial Activities of the Extract and Isolated Compounds from Austroplenckia populnea (Celastraceae)

Abstract

Austroplenckia populnea (Celastraceae), known as “marmelinho do campo”, is used in Brazilian folk medicine as antimicrobial, anti-inflammatory, and antitumoural agent. The aim of the present work was to evaluate the antimicrobial, antileishmanial and antimalarial activities of the crude hydroalcoholic extract of A. populnea (CHE) and some of its isolated compounds. The phytochemical study of the CHE was carried out affording the isolation of methyl populnoate (1), populnoic acid (2), and stigmast-5-en-3-O-β-(d-glucopyranoside) (3). This is the first time that the presence of compound 3 in A. populnea is reported. The results showed that the CHE presents antifungal and antibacterial activities, especially against Candida glabrata and Candida albicans, for which the CHE showed IC50 values of 0.7 μg mL-1 and 5.5 μg mL-1, respectively, while amphotericin B showed an IC50 value of 0.1 μg mL-1 against both microorganisms. Compounds 1D3 were inactive against all tested microorganisms. In the antileishmanial activity test against Leishmania donovani, the CHE showed an IC50 value of 52 μg mL-1, while compounds 2 and 3 displayed an IC50 value of 18 μg mL-1. In the antimalarial assay against Plasmodium falciparum (D6 and W2 clones), it was observed that all evaluated samples were inactive. In order to compare the effect on the parasites with the toxicity to mammalian cells, the cytotoxicity activity of the isolated compounds was evaluated against Vero cells, showing that all evaluated samples exhibited no cytotoxicity at the maximum dose tested.