Figure 4 – Synergistic effects of drug combinations against SARS-CoV-2 in Vero cells at 16 hpi.

(A.) Combination drug toxicity in Vero cells at 24 hours. Cells were seeded at a density of 3E4 and overlaid with media conditioned with 0.1% DMSO or the indicated concentration of inhibitor. Cells were incubated for 24 hours at 37°C at 5% CO2. Viability was determined using CellTiter Glo assay.

(B.) Efficacy of inhibitors combinations in Vero cells at 16 hpi. Cells were seeded at a density of 3E4 and overlaid with conditioned media containing 0.1% DMSO or 5:5 μM of Maraviroc plus indicated inhibitor. Cells were incubated for 2 hours and conditioned media was removed. Viral inoculum (MOI: 0.1) containing 5:5 μM of inhibitor combination was added to cells and incubated for 1 hour at 37°C and 5% CO2. Viral inoculum was removed, cells were washed with DPBS, and conditioned media was returned to the cells. Culture was incubated for 16 hpi after which supernatants were collected and a viral plaque assay was used to quantify the viral titers.

(C.) Inhibition that was observed at 16 hpi, represented as relative percentages.

The quantitative data are depicted as the mean of three biologically independent experiments ± SD. * p < 0.05; ** p < 0.01; *** p < 0.001; ****p < 0.0001.