Evaluation of Anti-leishmanial Effect of Selenium Nanoparticles on Leishmania major Promastigotes In Vitro

Background: Cutaneous leishmaniasis (CL) remains a major health threatening disease in Iran and many countries around the world. Antimony compounds are currently used to treat CL. Due to the side effects and high resistance, the use of alternative therapies, especially the use of nanoparticles, has been considered by researchers. The aim of this study was to investigate the anti-leishmanial activity of selenium nanoparticles (SeNPs) on Leishmania major in vitro. Methods: In this experimental study, the anti-leishmanial activity of the SeNPs was evaluated at concentrations of 1.25, 2.5, 5, 10, 25, 50, and 100 µg/mL at exposure times of 24, 48, and 72 hours on 106 live parasites. Then, the number of live parasites was counted by trypan blue using a neobar slide and light microscope (Hemocytometer method). Glucantime and distilled water were considered positive and negative controls, respectively. Then, 50% inhibitory concentration (IC50) values were calculated by SigmaPlot™ 13 software. All reactions were performed in triplicate, and the results were considered as average. Results: The results of this study revealed that all concentrations of SeNPs have anti-leishmanial activity. The concentration of 100 µg/mL of SeNPs had the highest anti-leishmanial effect (100%) after 72 hours of exposure. Further, the IC50 content of SeNPs on L. major after 24, 48, and 72 hours was calculated to be 42.76, 34.53, and 22.69 µg/mL, respectively. Conclusions: The results indicated that SeNPs in different concentrations has an inhibitory effect on the growth of L. major. However, further investigations are required to determine the efficacy of SeNPs in vivo.