Identification of some dietary flavonoids as potential inhibitors of TMPRSS2 through protein-ligand interaction studies and binding free energy calculations

The continuing threat of COVID-19 and deaths need an urgent cost-effective pharmacological approach. Here, we examine the inhibitory activity of a group of dietary bioactive flavonoids against the human protease TMPRSS2, which plays a major role in SARS CoV-2 viral entry. After the molecular docking studies of a large number of flavonoids, four compounds with high binding scores were selected and studied in detail. The binding affinities of these four ligands, Amentoflavone, Narirutin, Eriocitrin, and Naringin, at the active site of the TMPRSS2 target, were investigated using MD simulations followed by MM-PBSA binding energy calculations. From the studies, a number of significant hydrophobic and hydrogen bonding interactions between the ligands and binding site amino residues of TMPRSS2 are identified which showcase their excellent inhibitory activity against TMPRSS2. Among these ligands, Amentoflavone and Narirutin showed MM-PBSA binding energy values of -155.57 and -139.71 kJ/mol, respectively. Our previous studies of the inhibitory activity of these compounds against the main protease of SARS-COV2 and the present study on TMPRSS2 strongly highlighted that Amentoflavone and Naringin can exhibit promising multi-target activity against SARS-CoV-2. Moreover, due to their wide availability, no side effects, and low cost, these compounds could be recommended as dietary supplements for COVID patients or for the development of SARS-CoV-2 treatments.