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 IC50 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.