Fig. 4

The inhibitory effects of A. argyi, eriodictyol, and umbelliferone on the cellular entry of Vpp of SARS-CoV-2 S variants. HEK-293 T cells expressing ACE2 were infected with SARS-CoV-2 S protein pseudo viral variants with luciferase, including wild type A B1.1.7 (alpha) B B.1.351 (Beta) C Lineage P1 (Gamma) D B1.617.2 (Delta) E and B.1.429 (Epsilon) F after treatments with A. argyi, eriodictyol or umbelliferone at the indicated concentrations for 2 days, and the luciferase activities were measured to determine the infection rate with the pseudoviruses. Additionally, the cell viability also was examined in CCK-8 assays. Camostat (CAM), naphthofluorescein (NAP), and cepharanthine (CEP) were used as the positive controls for the inhibitions of TMPRSS2 and furin activities and the binding between S protein and ACE2, respectively. Data were shown as mean ± SEM from three independent experiments with triplicates. ** p < 0.01, *** p < 0.001, and **** p < 0.0001