Molecular docking study on phytoconstituents of traditional ayurvedic drug tulsi (ocimum sanctum linn.) against covid-19 mpro enzyme: an in silico study

Objective: The aim of the present study was to assess bioactive compounds found in Tulsi as potential COVID-19 Mpr °inhibitor using molecular docking and to provide scientific justification in term of its active ingredient to target protein for prevention and symptomatic treatment of COVID-19. Methods: COVID-19 Mpr °was docked with eight phytochemicals of Ocimum sanctum Linn. Using Autodock 4.2. Determination of active site and visualization of molecular interactions between ligands and target enzyme was done by Biovia Discovery Studio 4.5. Results: Our result demonstrates that Vicenin, Caryophyllene, Cirsimaritin, Isothymusin and Isothymonin have a better binding affinity to target enzyme. However, only Vicenin exhibited better binding energy i.e.-7.02 kcal/mol to COVID-19 Main protease among other phytochemicals through some responsible interactions to inhibit the replication of SARS-CoV-2 in the human body, whereas Caryophyllene and Cirsimaritin exhibited similar binding affinity i.e.-6.46 kcal/mol but different interactions with target enzyme. Conclusion: Tulsi (Ocimum sanctum Linn.) is a preeminent traditional drug of Ayurveda for prophylaxis and treatment of various ailments, including respiratory disorders like cough, cold and flu. With no specific therapies available, reevaluating and repurposing traditional drugs could be an effective approach for the prevention and treatment of SARS-CoV-2 infection. Therefore our study provides scientific evidence for the potential use of Tulsi as an adjunct therapy for the prevention and symptomatic treatment of COVID-19. However, further in vitro and in vivo studies should be conducted to validate use of proposed compounds in drug discovery and as therapeutics against COVID-19.