In vitro leishmanicidal activity of aurones

Abstract: A series of aurones with drug-potential for LEISHMANIA infections was identified IN VITRO using both a direct cytotoxicity assay against extracellular promastigotes of LEISHMANIA DONOVANI, L. INFANTUM, L. ENRIETTII, and L. MAJOR , and a test against intracellular amastigote forms of L. DONOVANI residing within murine macrophages. The most active aurone (6-hydroxy-2-[phenylmethylene]-3(2H)-benzofuranone) had an EC 50 of 0.45 μg/ml in the extra-, and an EC 50 of 1.40 μg/ml in the intracellular assay. Other aurones were active between 0.06 - 12.50 μg/ml and 0.04 - 7.81 μg/ml, respectively. When tested against murine bone marrow-derived macrophages as a mammalian host cell control, the compounds showed only moderate cytotoxicity (EC 50 2.32 to > 25.0 μg/ml). This is the first report on aurones as a new class of natural products with leishmanicidal activity.