Fig. 3.

Inhibitory effects of Radix et Rhizoma Rhei, Radix Polygoni multiflori, and Caulis Polygoni multiflori on the SARS-CoV S protein and ACE2 interaction. Biotin-labeled S protein (0.05 μg) was mixed with various amounts of aqueous extracts from Radix et Rhizoma Rhei (A), Radix Polygoni multiflori (B) or Caulis Polygoni multiflori (C), and the mixtures were added to wells, which were coated with 1 ng of ACE2. The biotinylated ELISA was performed as described in Section 2. Results are expressed as inhibition (%) described in Section 2. Values are mean ± standard error of six independent assays.