Therapeutic Effects of Co-administration of Silver Nanoparticles and Vitamin C on Vaginal Infection Caused by Group B Streptococcus

Background: Group B Streptococcus (GBS) is a bacterium commonly isolated from the vagina. Silver nanoparticles (SNPs) are potential antibacterial agents, and studies have shown their toxic effects. Vitamin C (VC) is an essential vitamin with a protective role against toxicological conditions. We aimed to the evaluation therapeutic effects of the co-administration of SNPs and VC on vaginal infection caused by GBS in mice models. Methods: Vaginitis model was established by intravaginal inoculation of GBS. The Co-administration of SNPs and VC was used to treat the infections. The antibacterial activity of SNPs was determined by the minimum inhibitory concentration. The toxicity of nanoparticles was measured by MTT assay. The microbial load and estrous cycle of mice during treatment were evaluated. Finally, blood samples and vaginal tissue sections were isolated and analyzed. Results: The results showed that SNPs have excellent effects on GBS, and the MIC was 512 ppm. Cell viability after exposure at 512 ppm of SNPs was 32.11% but after treatment with VC increased viability at 512 ppm of nanoparticles to 65.32%. In mice that received SNPs and VC at the same time, the bacteria were completely removed from the vagina, and estrus cycle returned to normal cycle. Analysis of the prepared blood samples and microscopic examination of the vaginal sections confirmed the results. Conclusion: SNPs have a potential antibacterial effect on GBS. But nanoparticles have toxic effects on mammalian cells. The simultaneous use of VC, as a powerful antioxidant, can completely eliminate this toxic effect of nanoparticles.