Inhibitory Effect of Phytochemicals from Azadirachta indica A Juss. and Tinospora cordifolia (Thunb.) Miers against SARS-CoV-2 M
pro and Spike Protease- An In Silico Analysis
COVID 19 caused by SARS-CoV-2 is spreading worldwide and affected 10 million people with a mortality rate between 0.5 % to 5%. Medicinal plants from China, Morocco, Algeria, Africa and India were tested for antiviral efficacy in SARS-CoV-2. Ayurveda Medicine described many medicinal plants. The Nimba ( Azadirachta indica A. Juss) is used in fever, bacterial and viral infections, and Amrita ( Tinospora cordifolia (Thunb.) Miers) is used as antiviral, antipyretic, and anti-inflammatory purposes. The combination of both these plants is called Nimbamritam, and it is widely used in pyrexia, dermatitis, viral infections, etc. Spike protease (PDB ID 6VXX) and M pro (PDB ID 6LU) were retrieved from RCSB and 16 ligands from A. indica and 6 ligands from T. cordifolia were obtained from IMPPAT and PubChem. AutoDock Vina embedded PyRx was used for docking. Remdesivir was taken as a reference drug. In silico study of Cordifolide A of T cordifolia showed the highest scores with -8.2 Kcal/mol and -10.3Kcal/mol with M pro protease and Spike protease respectively. Cordifolide A had 4 H bonds and Kaempferol had 7 non-conventional bonds, including van der Waal with M pro (6LU7) protease. The interactions with 6VXX had 5 H bonds in each ligand Cordifolide A and Azadirachtin B. The prevention of virus entry by targeting spike protease host receptor ACE2 and restricting replication of the viral genome by targeting M pro residues were identified in our study. A. indica and T. cordifolia are promising therapeutic agents in COVID 19.