In silico studies reveal potential antiviral activity of phytochemicals from medicinal plants for the treatment of COVID-19 infection

Abstract

Abstract The spread of COVID-19 across continents has led to a global health emergency. COVID-19 disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected nearly all the continents with around 1.52 million confirmed cases worldwide. Currently only a few regimes have been suggested to fight the infection and no specific antiviral agent or vaccine is available. Repurposing of the existing drugs or use of natural products are the fastest options available for the treatment. The present study is aimed at employing computational approaches to screen phytochemicals from the medicinal plants targeting the proteins of SARS-CoV2 for identification of antiviral therapeutics. The study focuses on three target proteins important in the life cycle of SARS-CoV-2 namely Spike (S) glycoprotein, main protease (Mpro) and RNA-dependent RNA-polymerase (RdRp). Molecular docking was performed to screen phytochemicals in medicinal plants to determine their feasibility as potential inhibitors of these target viral proteins. Of the 30 plant phytochemicals screened, Silybin, an active constituent found in Silybum marianum exhibited higher binding affinity with targets in SARS-CoV-2 in comparison to currently used repurposed drugs against SARS-CoV-2. Withaferin A from Withania somnifera also showed significant binding to the targets proteins. In addition, phytochemicals from Tinospora cordiofolia and Aloe barbadensis displayed good binding energetics with the target proteins in SARS-CoV-2. These results provide a basis for the use of traditional medicinal plants as alternative lines of treatment for COVID-19 infection.