Proposed mechanism of action (IMAGE) The University of Hong Kong Caption Proposed mechanism of action for orally administrated colloidal bismuth subcitrate together with N-acetyl cysteine as a broad-spectrum anti-coronavirus cocktail therapy. The pan-inhibitory activity of bismuth drugs against various CoVs may stem from their abilities to target multiple viral enzymes in the viral replication cycles. CBS as well as related metallodrugs could inactivate the viral cysteine protease through either targeting the key cysteine residue in the active site (PLpro and Mpro) or structural zinc-finger domain (PLpro and Hel) or even other zinc metalloproteins in human cells (ACE2) that are tightly associated with viral entry. Credit The University of Hong Kong Usage Restrictions This work is licensed for non-commercial, non-exclusive, one-time usage with attribution to the copyright holder. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.