Biosynthesis of Silver Nanoparticles by Bacillus subtilis and Their Anti-Leishmanial Activity in Vivo

Abstract

One of the most prevalent parasite infections in the Middle East is cutaneous leishmaniasis (CL). It is the first time in this work that in vitro anti-leishmanial effects of B. subtilis/AgNPs were examined on L. tropica promastigote, and their efficacies were compared with pentostam. These nanoparticles are described to confirm using the techniques: UV–-visible Spectroscopy (UV-Vis), where showed an absorption peak at 428 nm, and A scanning electron microscope, where the results showed that the sizes ranged between 41.5 - 68 nm at an average of 44.2 ± 1.13 nm, XRD was confirmed the presence of cubic crystal system has been identified to be due to silver metalfor. As for the FTIR analysis, several absorption peaks appeared, but a strong band shown at 3484.27 cm^-1 can be assigned to the primary amine N-H stretching that is present in the bacterial supernatant. Five NP concentrations were used, and each concentration of AgNPs displayed remarkable anti-leishmanial activity against L. tropica promastigotes in vitro. However, a concentration of (200 µg/ml) displayed a superior inhibitory impact on the growth of parasites compared to the rest of the other concentrations, where the rate of inhibition was the percentage 59.47 ± 2.7 after 24 hours. At 48 h and 72 h, the average percentage of parasite inhibition was 67.72±1.95 and 72.79 ± 0.45, respectively. The outcomes were remarkably similar to the reference medicine (pentostam). As for the lowest inhibition among the rest of the concentrations, it was the concentration (800 µg/ml), where the average percentage of inhibition reached 59.47 ± 2.7, 67.72 ± 1.95, and 72.79 ± 0.45 after 24, 48, and 72 hours, respectively.