摘要Objective:To investigate the leishmanicidal effect of the Bixa orellana crude seed extract and its fractions against Leishmania amazonensis. <br> Methods:Four main fractions (BO-A, BO-B, BO-C and BO-D) were obtained by exhaustion with solvent with increased polarity from the Bixa orellana crude seed extract and 28 sub-fractions. The antileishmanial activity was evaluated in intracellular amastigotes and the cytotoxicity was assessed in murine intraperitoneal macrophages. <br> Results:The BO-A and BO-B fractions showed a good antileishmanial activity with IC50 values of (12.9±4.1) and (12.4±0.3) μg/mL, respectively. The sub-fractions BO-B1 (IC50=(11.8±3.8) μg/mL) and BO-B3 [IC50=(13.6±4.7) μg/mL] also proved to have a good leishmanicidal effect. In general, the sub-fractions showed a lower toxicity than the crude extract. A selectivity index of 9 indicated a moderate selectivity of the BO-A, BO-B and BO-C fractions and BO-B1 sub-fraction. <br> Conclusions: Potential of this plant against cutaneous leishmaniasis should be further investigated.