Determining the antiviral activity of two polyene macrolide antibiotics following treatment in Kidney Cells infected with SARS-CoV-2

BackgroundThere has been much speculation that polyene macrolide antibiotics, such as amphotericin B (AmB) and Nystatin (NYS) may have antiviral activity against several viruses including SARS-CoV-2. ObjectiveThe objective of this short communication was to determine the antiviral activity of two polyene macrolides, AmB and NYS, following treatment in kidney cells infected with SARS-CoV-2. MethodsA serial dilution of AmB, NYS, and irbesartan (a drug known to bind to the ACE-2 receptor as a positive control) were then added (n=4 at each concentration) to the infected Vero76 kidney cells in 100 {micro}L media. Cells were also examined for contamination at 24 hours, and for cytopathic effect (CPE) and cytotoxicity (if noticeable) under a microscope at 48 hours. In a second study, AmB and Remdesivir were incubated in kidney cells infected with the virus and inhibition of the virus was determined by an immunoassay. Results and ConclusionsAmphotericin B (AmB) showed a significant reduction in the TCID50 titer, with the 50% effective concentration (EC50) of 1.24 {micro}M, which was 2.5 times lower than the cytotoxicity concentration. NYS and Irbesartan both exhibited substantially less active and would not be considered a suitable choice for further investigations. In addition, when measuring viral inhibition by immunoassay, AmB was significantly more potent than remdesivir (EC50 31.8 nM vs. 1.15 {micro}M). Taken together, these preliminary findings suggest that AmB may have significant activity against SARS-CoV-2. However, further cell and animal studies are warranted.