Umbelliferone and eriodictyol suppress the cellular entry of SARS-CoV-2

Artemisia argyi (A. argyi), also called Chinese mugwort, has been widely used to control pandemic diseases for thousands of years since ancient China due to its anti-microbial infection, anti-allergy, and anti-inflammation activities. Therefore, the potential of A. argyi and its constituents in reducing the infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was investigated in this study. Among the phytochemicals in A. argyi, eriodictyol and umbelliferone were identified to target transmembrane serine protease 2 (TMPRSS2) and angiotensin-converting enzyme 2 (ACE2) proteins, the essential factors for the cellular entry of SARS-CoV-2, in both FRET-based enzymatic assays and molecular docking analyses. These two ingredients of A. argyi suppressed the infection of ACE2-expressed HEK-293 T cells with lentiviral-based pseudo-particles (Vpp) expressing wild-type and variants of SARS-CoV-2 spike (S) protein (SARS-CoV-2 S-Vpp) via interrupting the interaction between S protein and cellular receptor ACE2 and reducing the expressions of ACE2 and TMPRSS2. Oral administration with umbelliferone efficiently prevented the SARS-CoV-2 S-Vpp-induced inflammation in the lung tissues of BALB/c mice. Eriodictyol and umbelliferone, the phytochemicals of Artemisia argyi, potentially suppress the cellular entry of SARS-CoV-2 by preventing the protein binding activity of the S protein to ACE2.