Abstract
The process of investigating a possible cure for coronavirus disease 2019 (COVID-19) in vitro and in vivo may take a long time. For this reason, several in silico studies were performed in order to produce preliminary results that could lead to treatment. Extract of Juniperus procera Hochst is used as a traditional medicine for recovery from flu in Saudi Arabia. In the present study, more than 51 phytochemicals of J. procera were docked against the main protease of COVID-19. Rutin gave the highest interaction score among all the phytochemicals and the commercially available antiviral drugs. Lopinavir showed the second highest binding score. Rutin and lopinavir were further investigated using homology models of COVID-19. Rutin showed a better inhibition score in 9 of the 11 of homology models compared with lopinavir. Analysis of ligand-protein interaction contacts revealed that 3 residues (Glu166, Gly143, and Thr45) of the main protease formed hydrogen bonds with rutin. This simulation study suggests that rutin could be a possible effective inhibitor of several COVID-19 protein targets, including the main protease. Rutin, already available for commercial use, was evaluated for its ability as a possible drug. To our knowledge, this is the first study that suggests rutin having a possible strong inhibitory role against several protein targets of COVID-19.