In vitro leishmanicidal activity of monomeric and dimeric naphthoquinones

A series of monomeric and dimeric naphthoquinones with potential for treatment of 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 L. donovani residing within murine macrophages. Several naphthoquinones proved to be active at concentrations in the microgram range (EC50 0.9–17.0 μg/ml). When tested against a panel of human cancer cell lines (KB, SKMel, A549, MDA) and murine bone marrow culture-derived macrophages (BMMΦ) as mammalian host cell controls, compounds with anti-Leishmania-activity showed moderate (EC50>25 μg/ml) to pronounced (EC50<10 μg/ml) toxic effects.