In vitro antileishmanial activity of Brazilian plant species

Abstract

Leishmaniasis is an infectious disease still widely spread in Brazil. It is a public health problem for the country due to its magnitude and geographic expansion leading to a complex, expensive and laborious control system [1, 2]. There is an urgent need to search for new medicines to treat leishmaniasis. Natural products can provide unlimited opportunities for the discovery of new lead compounds targeting this neglected disease. In this work, we investigated the antileishmanial activity of 22 plant extracts, from seven different species belonging to Apocynaceae, Asteraceae, Ebenaceae, Primulaceae and Rutaceae families. Samples were evaluated against promastigotes from L. infantum (strain BH46). The antileishmanial activity was measured 24h after exposition to the sample using the resazurin-based viability assay [3]. The toxicity of test samples is currently being investigated using dye exclusion method for cell viability using non-infected macrophages. According to preliminary results, four extracts from Aspidosperma spp. showed antileishmanial activity. The dichloromethane (DCM) extract from the stem showed an IC50 value of 89.5 ± 4.9 µg/mL. The IC50 of the remaining active extracts is currently being determined. The antileishmanial activity of this species will be further investigated, using intra- and extracellular parasite forms from other Leishmania species. The metabolic profiling and targeted isolation of bioactive constituents are in progress aiming for the identification of new lead compounds with antileishmanial activity.