Fig 4. Characterization of the mechanisms of NhPV and Suramin for their anti-SARS-CoV-2-SP action.
A) Time-dependent inhibition of SPΔCG614-PVs infection mediated by NhPV or Suramin. NhPV (100 μg/mL) or Suramin (100 μg/mL) was added at 1 hr prior to infection, during infection (0 hr), and at 1 hr, and 3 hr pi. The positive controls (P.C.) were 293TACE2 cells infected with SPΔCG614-PVs in the absence of compounds. At 3 hrs pi, all of the cell cultures were replaced with fresh DMEM and cultured for 48 hrs. Then, the Gluc activity was monitored in the supernatant, and the data are shown as a percentage of inhibition (%). B) Inhibitory effect of NhPV or Suramin on SARS-CoV2-SP/ACE2 binding by ELISA as described in materials and methods. nAB: anti-COVID-19 neutralizing antibody (SAD-S35). The results are the mean ±S.D. of duplicate samples, and the data are representative of results obtained in two independent experiments.