Antileishmanial and antioxidant potential of the ethanol extract of croton argyrophylloides

Leishmaniasis is a severe and potentially fatal chronic disease caused by Leishmania spp. The treatment primarily based on antimony is not always effective and have toxic effects. Secondary metabolites of plants are considered promising agents with antileishmanial action. The objective of this study was to evaluate the in vitro antileishmanial activity of the Croton argyrophylloides leaves ethanol extract (CALEE), popularly known as marmeleiro prateado, as well determine the main classes of metabolites present, the antioxidant activity and toxicity in Artemia salina using the BST method. The antileishmanial test was performed in vitro against promastigotes forms of Leishmania infantum in a 96-well plate (106 parasites per well).The CALEE was dissolved in DMSO and tested at five concentrations from 100 μg/ml on. Pentamidine was used as a standard drug. The effective concentration that kills 50% of the culture (EC50) was determined using the MTT colorimetric test, and the measurement was performed in a microplate reader at 570 nm. The CALEE presented superior antileishmanial activity to pentamidine, with EC50 5.63 and 23.71 μg/ml respectively, moderate antioxidant activity, as well as activity against A. salina in BST test (EC50 266.34 μg/ ml). Therefore, the CALEE is presented as a potential source for the extraction of compounds with antileishmanial activity.