Effect of bismuth lipophilic nanoparticles (BisBAL NPs) on Trichomonas vaginalis growth

The most common treatment to trichomoniasis is the use of metronidazole; however several studies have shown that at least 5% of clinical cases of trichomoniasis are caused by parasites resistant to the drug. Lipophilic bismuth nanoparticles (BisBAL NPs) have an important antimicrobial activity; however the influence of BisBAL NPs on human parasites has not been studied. The objective of this study was to determine the effect of bismuth lipophilic nanoparticles on Trichomonas vaginalis growth. The bismuth nanoparticles synthesized by colloidal method are composed of ≥100 nm crystallites and have a spherical structure, agglomerating into clusters of small nanoparticles. Based on cell viability assays and fluorescence microscopy, Trichomonas vaginalis growth was inhibited with the addition of 62.5-125 μg/mL of BisBAL NPs. Fluorescence micrographs showed live T. vaginalis in absence of any drug treatment and after exposed for 24 h. with 500 μg/mL of BisBAL NPs or 1.3 μg/mL metronidazole a dark background was observed with cellular debris stain. In summary, here we present evidence for first time of the antiparasitic activity of lipophilic bismuth nanoparticles being as effective as metronidazole to interfere with T. vaginalis growth. BisBAL nanoparticles could be an interesting alternative to treat and prevent parasitic infections.