In vitro activity of 1H-phenalen-1-one derivatives against Leishmania spp. and evidence of programmed cell death

Background The in vitro activity against Leishmania spp. of a novel group of compounds, phenalenone derivatives, is described in this study. Previous studies have shown that some phenalenones present leishmanicidal activity, and induce a decrease in the mitochondrial membrane potential in L. amazonensis parasites, so in order to elucidate the evidence of programmed cell death occurring inside the promastigote stage, different assays were performed in two different species of Leishmania. Methods We focused on the determination of the programmed cell death evidence by detecting the characteristic features of the apoptosis-like process, such as phosphatidylserine exposure, mitochondrial membrane potential, and chromatin condensation among others. Results The results showed that four molecules activated the apoptosis-like process in the parasite. All the signals observed were indicative of the death process that the parasites were undergoing. Conclusions The present results highlight the potential use of phenalenone derivatives against Leishmania species and further studies should be undertaken to establish them as novel leishmanicidal therapeutic agents.