FDA approved drugs with broad anti-coronaviral activity inhibit SARS-CoV-2 in vitro

Stuart Weston; Rob Haupt; James Logue; Krystal Matthews; Matthew B. Frieman

All drug screens were performed with Vero E6 cells. Cells were plated in opaque 96 well plates one day prior to infection. Cells were pre-treated with drug at a range of concentrations for 2 hours (h) at 37°C/5% CO2. Drug stocks were made in either DMSO, water or methanol. Drugs were diluted from stock to 50µM and an 8-point, 1:2 dilution series made and infected at MOI 0.01 and 0.004. Vehicle controls were used on every plate, and all treatments were performed in triplicate for each screen. In addition to plates that were infected, parallel plates were left uninfected to monitor cytotoxicity of drug alone. Additionally, plates with untreated, uninfected cells and plates without cells were processed as controls. Three independent screens with this set-up were performed. Cells were incubated at 37°C/5% CO2 for 3 days before performing CellTiter-Glo (CTG) assays as per the manufacture's instruction (Promega). Luminescence was read using a Molecular Devices Spectramax L plate reader. Fluphenazine dihydrochloride, benztropine mesylate, amodiaquin hydrochloride, amodiaquin dihydrochloride dihydrate, thiethylperazine maleate, mefloquine hydrochloride, triparanol, terconazole vetranal, anisomycin, fluspirilene, clomipramine hydrochloride, hydroxychloroquine sulfate, promethazine hydrochloride, emetine dihydrochloride hydrate and chloroquine phosphate were all purchased from Sigma. Chlorpromazine hydrochloride, toremifene citrate, tamoxifen citrate, gemcitabine hydrochloride and imatinib mesylate were all purchased from Fisher Scientific.