In vitro antileishmanial efficacy of antiplasmodial active aminoquinoline-chalcone hybrids.

Significant overlaps in the geographical distribution of malaria and leishmaniasis increase the risk for comorbidity, which can affect treatment efficacy, cotreatment compatibility and disease progression. These concerns are also exacerbated by the existing shortcomings of malaria and leishmaniasis treatments. There is, therefore, a pressing need for new anti-infective drugs for both individual diseases and coinfections. The in vitro antileishmanial activity of previously synthesized antiplasmodial aminoquinoline-chalcone hybrids was evaluated. Hybrid 6, featuring a N-methyl-1,3-propylene diamine linker between pharmacophores, was 11-fold more potent in anti-amastigote activity against Leishmania major, responsible for cutaneous leishmaniasis, the most common form of the disease, in comparison to chloroquine. Hybrid 7, with a 2,2-(ethylenedioxy)bis(ethylamine) linker, was nearly 7-fold more active in anti-amastigote activity against Leishmania donovani, responsible for visceral leishmaniasis, the most lethal form of the infection. Although these two hybrids were less potent than the clinically used antileishmanial, amphotericin B, they still qualify as hits against both Plasmodium and Leishmania strains. Accordingly, this may lend them as potential agents against Leishmania-Plasmodium coinfections, which will require further investigation using in vitro co-cultures and subsequent in vivo testing for confirmation.