Evaluation of in vitro activity of copper gluconate against SARS-CoV-2 using confocal microscopy-based high content screening

ContextSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that emerged late in 2019 is the etiologic agent of coronavirus disease 2019 (Covid-19). There is an urgent need to develop curative and preventive therapeutics to limit the current pandemic and to prevent the re-emergence of Covid-19. This study aimed to assess the in vitro activity of copper gluconate against SRAS-CoV-2. MethodsVero E6 cells were treated with copper gluconate 18 hours before infection. Cells were infected with a recombinant GFP expressing SARS-CoV-2. Infected cells were maintained in fresh medium containing copper gluconate for an additional 48-hour period. The infection level was measured by the confocal microscopy-based high content screening method. The cell viability in presence of copper gluconate was assessed by XTT assay. ResultsThe viability of Vero E6 cells treated with copper gluconate up to 200 M was found to be similar to that of untreated cells, but it dropped below 40% with 400 M of this agent. The infection rate was 23.8%, 18.9%, 20.6%, 6.9%, 5.3%,5.2% in cells treated with 0, 2, 10, 25, 50 and 100 M of copper gluconate respectively. As compared to untreated cells, the number of infected cells was reduced by 71%, 77%, and 78% with 25, 50, and 100 M of copper gluconate respectively (p View larger version (26K): org.highwire.dtl.DTLVardef@1f99949org.highwire.dtl.DTLVardef@1bebae6org.highwire.dtl.DTLVardef@e05e37org.highwire.dtl.DTLVardef@49a3b2_HPS_FORMAT_FIGEXP M_FIG C_FIG