Targeting the vital non-structural proteins (NSP12, NSP7, NSP8 and NSP3) from SARS-CoV-2 and inhibition of RNA polymerase by natural bioactive compound naringenin as a promising drug candidate against COVID-19

The prevalence of SARS-CoV-2-induced respiratory infections is now a major challenge worldwide. There is currently no specific antiviral drug to prevent or treat this disease. Infection with COVID-19 seriously needs to find effective therapeutic agents. In the present study, naringenin, as a potential inhibitor candidate for RNA Polymerase SARS-CoV-2 was compared with remdesivir (FDA-approved drug) and GS-441,524 (Derivative of the drug remdesivir) by screening with wild-type and mutant SARS-CoV-2 NSP12 (NSP7-NSP8) and NSP3 interfaces, then complexes were simulated by molecular dynamics (MD) simulations to gain their stabilities. The docking results displayed scores of -3.45 kcal/mol and -4.32 kcal/mol against NSP12 and NSP3, respectively. Our results showed that naringenin had Delta G values more negative than the Delta G values of Remdesivir (RDV) and GS-441,524. Hence, naringenin was considered to be a potential inhibitor. Also, the number of hydrogen bonds of naringenin with NSP3 and later NSP12 are more than Remdesivir and its derivative. In this research, Mean root mean square deviation (RMSD) values of NSP3 and NSP12with naringenin ligand (5.55 +/- 1.58 nm to 3.45 +/- 0.56 nm and 0.238 +/- 0.01 to 0.242 +/- 0.021 nm, respectively showed stability in the presence of ligand. The root mean square fluctuations (RMSF) values of NSP3 and NSP12 amino acid units in the presence of naringenin in were 1.5 +/- 0.31 nm and 0.118 +/- 0.058, respectively. Pharmacokinetic properties and prediction of absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of naringenin and RDV showed that these two compounds had no potential cytotoxicity.