Fig. 1

Evaluation of antiviral activity of drug candidates against SARS-CoV-2 in vitro. The dose-response curves of single drug treatments against SARS-CoV-2 are shown; (A) niclosamide, (B) ivermectin, and (C) chloroquine. Vero E6 cells were treated with various concentrations of drug for 1 hour and followed by SARS-CoV-2 infection at MOI of 0.01. After removing of virus, the cells were maintained in the medium containing drugs or 0.5%DMSO for 2 days. The virus supernatants were collected for titration using the plaque assay and one step-qRT-PCR. The dose-response curves were expressed as the percent inhibition in relative to DMSO-treated cell control. The effect of drug treatment on the cell viability was determined using MTT assay and is expressed in relative to the DMSO-treated cell control. The experiments were repeated at least three times, and data are shown as mean ± SD