Ayurveda botanicals in COVID-19 management: An in silico- multitarget approach

The Coronavirus disease (COVID-19) caused by the virus SARS-CoV-2 has become a global pandemic in a very short time span. Currently, there is no specific treatment or vaccine to counter this highly contagiousdisease. Presently, existing anti-virals and disease-modifying agents are being repurposed to manage COVID-19. There is an urgent need to find a specific cure for the disease and global efforts are directed at developing SARS-CoV-2 specific anti-viralsand immunomodulators.The objective of this study is to explore the immunomodulatory and anti-SARS-CoV-2 potential of key phytoconstituents from Ayurveda based Rasayana drugs, Withania somnifera (Ashwagandha), Tinospora cordifolia (Guduchi) and Asparagus racemosus (Shatavari) using in silico approaches like network pharmacology, and molecular docking. The SWISS-ADME tool was used to predict the pharmacokinetic and pharmacodynamic (PK-PD) interactions and drug likeliness potential. Using these approaches we propose a library of phytomolecules with potential to be developed as phytopharmaceuticals for COVID 19 management.The plant extracts were prepared as per Ayurvedic procedures and a total of 31 phytoconstituents were identified using HPLC and MS studies. The network pharmacology model shows that these phytoconstituents possess the potential to modulate several immune pathways. Amongst the three botanicals Withania somnifera was found to be the most potent immunomodulator through its potential to modulate T cell differentiation, NK cell cytotoxicity as well as T cell, B cell and NOD-like receptor signalling pathways.Molecular docking studies showed thatseveral phytoconstituents possess good affinity for the Spike protein, Main Protease and RNA dependent RNA polymerase of SARS-CoV-2 suggesting their application for the termination of viral life cycle. Further, predictive tools indicate that there would beneficial herb-drug pharmacokinetic-pharmacodynamic interactions with concomitantly administered drug therapy. We thus make a compelling case to evaluate the potential of these Rasayana botanicals in the management of COVID-19 following rigorous experimental validation.