In-silico analysis of the inhibition of the SARS-CoV-2 main protease by some active compounds from selected African plants

Objectives: Over the years, Azadirachta indica, Mangifera indica, and Moringa oleifera have been shown to possess some antiviral characteristics. This study applies molecular docking techniques to assess inhibitory effects of some bioactive compounds from the plants mentioned above against the main protease (Mpro), a key protein involved in SARS-CoV-2 replication. Furthermore, adsorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles for screened compounds were predicted in silico. Methods: The crystal structure of Mpro was retrieved from the Protein Data Bank, while the plant bioactive compounds were retrieved from Pubchem. Drug-likeness of the selected compounds and a control drug (hydroxychloroquine) were assessed, and the compounds that satisfied the drug-likeness rule were docked against Mpro. The docked complexes were analyzed using LigPlot and the protein-ligand profiler server. The top five compound hits were subjected to ADMET screening using the ADMETSar server. Results: A total of 17 out of 22 screened compounds passed Lipinski's assessment. Additionally, the most active compounds from the investigated plants exhibited relative inhibitory potentials against Mpro compared with hydroxychloroquine, which alludes to their possible involvement in inhibiting the SARS-CoV-2 main protease replication process. Conclusions: In our study, most of the active phytocomponents of the investigated plants exhibited relative inhibitory potentials against Mpro of SARS-CoV-2 and preferred pharmacological features when compared with hydroxychloroquine. These findings indicate these compounds are potentially antiviral candidates against SARS-CoV-2.