High Efficacy of Green Synthesized Silver Nanoparticles for Treatment of Toxoplasma Gondii Infection Through Their Immunomodulatory, Anti-Inflammatory, and Antioxidant Potency

The present experimental survey designed to green synthesis, characterization, as well as in vitro and in vivo anti-Toxplasma gondii activity of silver nanoparticles (SLN) green synthesized by Lupinus arcticus extract. SLN were green synthesized based on the reducing by L. arcticus extract through the precipitation technique. In vitro lethal effects of SLN on T. gondii tachyzoites, infectivity rate, parasites inside of the human macrophage cells (THP-1 cells), nitric oxide (NO) triggering, and iNOS and interferon gamma (IFN-γ) expression genes were evaluated. In vivo, after establishment of toxoplasmosis in BALB/c mice via T. gondii ME49 strain, mice received SLN at 10 and 20 mg/kg/day alone and combined to pyrimethamine at 5 mg/kg for 14 days. SLN exhibited a spherical form with a size ranging from 25 to 90 nm. The 50% inhibitory concentration (IC₅₀) value of SLN and pyrimethamine against tachyzoites was 29.1 and 25.7 µg/mL, respectively. While, the 50% cytotoxic concentration (CC₅₀) value of SLN and pyrimethamine against THP-1 cells was 412.3 µg/mL and 269.5 µg/mL, respectively. SLN in combined with pyrimethamine obviously (p < 0.05) decreased the number and size of the T. gondii cysts in the infected mice. The level of NO, iNOS and IFN-γ genes was obviously (p < 0.001) upregulated. SLN obviously (p < 0.05) decreased the liver level of oxidative stress and increased the level of antioxidant factors. The findings displayed the promising beneficial effects of SLN mainly in combination with current synthetic drugs against latent T. gondii infection in mice. But we need more experiments to approve these findings, clarifying all possible mechanisms, and its efficiency in clinical phases.