In Silico Studies of Essential Oils of Cymbopogon Citratus and Piper Betle as Prophylaxis against COVID-19

The coronavirus disease 2019 (COVID-19) is a highly infectious disease that still endangers the lives of many people worldwide. In an effort to develop preventive strategies, this research serves as a preliminary study by screening a vast number of natural compounds from Cymbopogon citratus Stapf. (lemongrass) and Piper betle L. (betel) essential oils to generate prophylactic measures against COVID-19 by a series of in silico studies, namely chemical characterization, ADMET prediction, molecular docking and gene enrichment analysis. In total, six targets (RdRp, Mpro, PLpro, Nucleocapsid, Spike, and ACE2) and 186 natural compounds were predicted through molecular docking study. The gene enrichment analysis revealed that the integrated-actions of the compounds may modulate several COVID-19 related genes and are involved in numerous pathways in association to the pathogenesis and body's immune system. Among the most promising molecules, geranyllinalool, isoeugenyl phenylacetate, terpinen-4-ol acetate, and precocene II have been predicted to possess good inhibitory effects against SARS-CoV-2 related targets and modulate the key important genes including IFNG, CD14, TNFRSF1A, GAPDH, HMOX1, and NOS2. Taken together, three layers of prophylactic mechanisms by lemongrass and betel essential oil compounds were proposed against COVID-19: (1) immune system enhancement; (2) suppression of proinflammatory cytokines; (3) hypoxia symptoms management. This research will provide a basis for further investigation of in vitro, pre-clinical and clinical trials of selected compounds against COVID-19.