Synergistic effect of application of direct current electricity in combination with selenium nanoparticles on the killing of Leishmania major promastigotes in vitro

Regarding some reports on the resistance of Leishmania to Glucantime and the absence of an effective vaccine for the prevention of cutaneous leishmaniasis, there is an urgent need to identify a new and effective therapeutic method. Therefore, the present study aimed to examine the effect of direct current electricity in combination with selenium nanoparticles on the killing of Leishmania major in vitro. In this experimental study, the effect of different concentrations of selenium nanoparticles was evaluated against Leishmania major promastigotes in vitro. In the second step, the killing effect of selenium nanoparticles alone or in combination with 3 mA direct electric current was assessed in promastigote culture for 10 minutes. Then, the survival rate of the infected promastigotes was evaluated using the Microculture Tetrazolium Assay. The various concentrations of selenium nanoparticles significantly decreased the number of live promastigotes over time. Based on the parasite count, the half inhibitory concentration (IC50) of the nanoparticles was calculated 12.5 μg/ml after 24 hours of cultivation. Using selenium nanoparticles alone at the concentration of 100 μl/ml and in combination with 3 mA direct current electricity after 10 minutes caused 37.1% and 91.5% mortality in the promastigotes, respectively. Although the use of selenium nanoparticles alone cannot kill the Leishmania major promastigotes completely, the combined use of both direct current electricity and selenium nanoparticles has a significant synergistic effect on promastigote mortality.