Abstract
Disulfiram is an FDA-approved drug that has been used to treat alcoholism and has demonstrated a wide range of anti-cancer, anti-bacterial, and anti-viral effects. In the global COVID-19 pandemic, there is an urgent need for effective therapeutics and vaccine development. According to recent studies, disulfiram can act as a potent SARS-CoV-2 replication inhibitor by targeting multiple SARS-CoV-2 non-structural proteins to inhibit viral polyprotein cleavage and RNA replication. Currently, disulfiram is under evaluation in phase II clinical trials to treat COVID-19. With more and more variants of the SARS-CoV-2 worldwide, it becomes critical to know whether disulfiram can also inhibit viral entry into host cells for various variants and replication inhibition. Here, molecular and cellular biology assays demonstrated that disulfiram could interrupt viral spike protein binding with its receptor ACE2. By using the viral pseudo-particles (Vpps) of SARS-CoV-2, disulfiram also showed the potent activity to block viral entry in a cell-based assay against Vpps of different SARS-CoV-2 variants. We further established a live virus model system to support the anti-viral entry activity of disulfiram with the SARS-CoV-2 virus. Molecular docking revealed how disulfiram hindered the binding between the ACE2 and wild-type or mutated spike proteins. Thus, our results indicate that disulfiram has the capability to block viral entry activity of different SARS-CoV-2 variants. Together with its known anti-replication of SARS-CoV-2, disulfiram may serve as an effective therapy against different SARS-CoV-2 variants.