Phytocompounds of Rheum emodi, Thymus serpyllum and Artemisia annua inhibit COVID-19 binding to ACE2 receptor: In silico approach
Rajan Rolta, Deeksha Salaria, Vikas Kumar, Anuradha Sourirajan, Kamal Dev · 2020
Abstract COVID-19 has been declared as global epidemic and currently there is no drug/vaccine available to treat COVID-19. All over the world, several studies are being conducted to discover the antiviral drugs against COVI-19. Traditional medicinal plants have long history to treat viral infections. We adopted in silico approach to find out if unique phytocompounds such as emodin (Rheum emodi), thymol and carvacrol (Thymus serpyllum) and artemisnin (Artemisia annua) could physically bind COVID-19 target proteins such as SARS-CoV-2 spike glycoprotein (PDB ID: 6VXX), SARS-CoV-2 spike ectodomain structure (PDB ID: 6VYB), and SARS coronavirus spike receptor-binding domain (PDB ID: 2AJF) and in turn preventCOVID-19 binding to the host receptor ACE2. Since Chloroquine (a standard antimalarial drug) has been looked as potential therapy against COVID-19, we also compared the binding of chloroquine and plant origin artemisnin antimalarial drug for its interaction with 6VXX, 6VY and 2AJF. Molecular docking studies using AutoDock/Vina software revealed that among all the phytocompounds artemisinin showed best binding affinity with 6VXX, 6VYB and 2AJF with Etotal -10.5 KJ mol-1, -10.3 KJ mol-1, and -9.1 KJ mol-1 respectively. Whereas emodin, carvacrol and thymol binds with 6VXX, 6VYB and 2AJF with Etotal -6.4, -6.8, -6.9 KJ mol-1, -8.8, -6.8, -7.4 KJ mol-1, and -6.9, -7.4, -7.2 respectively. Similarly, with Autodock/Vina chloroquine showed less binding affinity with 6VXX (-5.6 KJ mol-1), 6VYB (-5.9 KJ mol-1) and 2AJF (-6.4 KJ mol-1) as compared to all phytocompounds. Toxicity prediction showed non-toxicity and non-carcinogen by admetSAR and PROTOX‑II software.