In Vitro Sensitivity of Leishmania Promastigotes to Pentamidine Isethionate

The aim of this study was to evaluate the in vitro sensibility of Leishmania parasites to pentamidine isethionate in order to know their possible therapeutic response, by means of cytotoxicity assays using promastigotes of Leishmania major and Viannia complex Leishmania spp, etiological agents of the disease. The in vitro sensitivity of Leishmania promastigotes to pentamidine isethionate at different time points was determined. It was established that L. major is less sensitive to this drug than Viannia complex species. The drug demonstrated a higher median effective concentration (EC50) between 3.24 (12 h) and 0.08 (72 h) mu g/mL for L. major with respect to Viannia complex species. The use of the free forms of Leishmania in this study for in vitro sensitivity screening of parasite species to pentamidine isethionate allowed confirmation that the drug is effective against New World species and could eventually be used to treat cases of leishmaniasis caused by Old World parasites.