Green synthesized silver nanoparticles from Moringa : Potential for preventative treatment of SARS-CoV-2 contaminated water

Biogenic silver nanoparticles have been reported as good antimicrobial candidates. Thus, this study investigated the antiviral activity of silver nanoparticles synthesized against SARS-CoV-2. The silver nanoparticle was biosynthesized using leave extracts of Moringa oleifera (AgNPmo) and characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and X-ray diffractometry (XRD). The AgNPmo was first tested on clinical bacterial isolates, Pseudomonas aeruginosa (ATTC 154423) and Staphylococcus aureus (ATTC 209233), to ascertain its antimicrobial potential. In-vitro studies were also conducted to determine the cytotoxicity effect of AgNPmo on Vero cells. The efficacy and concentration of AgNPmo against SARS-CoV-2 were evaluated using a qPCR assay in a dose-dependent manner. The results demonstrated the successful biosynthesis and characterization of AgNPmo and its efficacy against the bacterial isolates. The AgNPmo showed low toxicity on the Vero cells. The IC ₅₀ from the cytotoxicity assay demonstrated the antiviral activity of the AgNPmo on the SARS-CoV-2 virus, leading to an increase in the Cycle threshold values, notably at 48 hours of incubation and at low concentrations. The results showed that the biogenic AgNPmo synthesized was cost-effective and showed both antimicrobial and antiviral potentials. These findings suggest that the nanoparticles could be a promising alternative for combating SARS-CoV-2, especially for water purification and preventing transmission.