Fig. 1.

Evaluation of antiviral activity of six drug candidates against SARS-CoV-2 in vitro. Vero E6 cells were infected by SARS-CoV-2 at a MOI of 0.01 and treated 1 h post infection (hpi) with serial dilutions of remdesivir, lopinavir, chloroquine, berberine, cyclosporine A and arbidol (umifenovir). Viral production was measured 48 hpi and expressed in relative values compared to the vehicle-treated control. The impact of treatment on cell viability was assessed by MTS assay (CellTiter 96® AQueous One Solution Cell Proliferation Assay, Promega), and expressed in relative values compared to control. Cell viability measurements were performed to ensure that molecular viral quantification was performed within a non-cytotoxic concentration range that could bias the measurement.