Recently, a new and fatal strain of coronavirus named as SARS-CoV-2 (Disease: COVID-19) appeared in Wuhan, China in December of 2019. Due to its fast growing human to human transmission and confirmed cases in nearly every country, it has been declared as pandemic by World Health Organisation (WHO) on 11 March 2020. Till now, there is no therapy such as vaccines and specific therapeutic agents available globally. Inspite of this, some protease inhibitors and antiviral agents namely lopinavir, ritonavir, remdisivir and chloroquine are under investigation and also implemented in several countries as therapeutic agents for the treatment of COVID-19. Seeing the health crisis across the world, it was our aim to find out a suitable drug candidate which could target SARS-CoV-2.For this purpose, molecular docking of 7 proteinsof SARS-CoV-2 was done with 18active constituents that have previously been reported to be antiviral or anti-SARS-CoV agents. The docking results of these 18 compounds were compared with 2 FDA approved drugs that have are currently being used in COVID 19, namely Remdesivir and Chloroquine. Our result revealed that among all, epigallocatechin gallate (EGCG), a major constituent of green tea, is the lead compound that could fit well into the binding sites of docked proteins of SARS-CoV-2. EGCG showed very strong molecular interactions with binding energies -9. 30, -8.66, -8.38, -7.57, -7.26, -6.99 and -4.90 kcal/mole for6y2e, 6vw1, 6vww, 6lxt,6vsb, 6lu7 and 6lvnproteins of SARS-CoV-2, respectively.Therefore, EGCG as per our results, should be explored as a drug candidate for the treatment of COVID-19.

No abstract

Luteolin (Lut) is an important plant-derived flavonoid that is widely distributed in edible herbs and vegetables. Studies on animal and human models have shown that Lut exhibits various pharmacological properties, viz. anti-inflammatory, anti-cancer, anti-oxidant, anti-apoptotic, and neurotrophic actions. The ongoing pandemic coronavirus disease-2019 (COVID-19), is a disease of the respiratory tract that consists of mild to severe symptoms of pneumonia including fever, muscle aches, sore throat, coughing, and shortness of breath. It is of particular concern in older people and patients with chronic diseases having cardiovascular and blood clotting issues or who have compromised immune. This situation prompted us to evaluate the bioactive compounds which are being used to prevent respiratory-related illness. Lut is one such compound which is used as an anti-inflammatory agent. Several studies have explained the protective nature of Lut by inhibiting virus entry and fusion with human receptors in old SARS-CoV that had emerged in 2003. Thus, regular consumption of foods having adequate amount of Lut in our diet may be helpful in inhibiting the SARS-CoV-2 infection as well and may prevent the consequent symptoms in COVID-19 patients. In present work, we have carried out the molecular docking studies of Lut with six different SARS-CoV-2 encoded key proteins. The FDA-approved drug remdesivir was also evaluated as control to compare the results. Lut showed excellent inhibitory action against papain-like proteinase, a main protease of SARS-CoV-2. Lut was also many times more active than remdesivir. Therefore, the foods which have Lut in adequate amount might be explored further for potential use against COVID-19

No abstract

The present study explores the efficacy of plant-derived natural products (PDNPs) against spike glycoproteins (S-glycoprotein) of SARS-CoV-2 variants using molecular docking, ADMET, molecular dynamics (MD) simulation and density-functional theory (DFT) analysis. In all, 100 PDNPs were screened against spike glycoprotein of SARS-CoV-2 variants, namely alpha (B.1.1.17), beta (B.1.351), delta (B.1.617), gamma (P.1) and omicron (B.1.1.529). Results showed that rutin, EGCG, hesperidin, withanolide G, rosmarinic acid, diosmetin, myricetin, epicatechin and quercetin were the top hit compounds against each of the SARS-CoV-2 variants. The most active compounds, rutin, hesperidin, EGCG and rosmarinic acid gave binding scores of −10.2, −8.1, −8.9, −8.3 and −9.2 kcal/mol, against omicron, delta, alpha, beta and gamma variants, respectively. Further, the stability of docked complexes was confirmed by the analysis of molecular descriptors (RMSD, RMSF, SASA, Rg and H-bonds) in molecular dynamic simulation analysis. Moreover, the physiochemical properties and drug-likeness of the tested compounds showed that they have no toxicity or carcinogenicity and may be used as druggable targets. In addition, the DFT study revealed the higher activity of the tested compounds against the target proteins. This led us to conclude that rutin, hesperidin, EGCG and rosmarinic acid are good candidates to target the S-glycoproteins of SARS-CoV-2 variants. Further, in vivo and clinical studies needed to develop them as drug leads against existing or new SARS-CoV-2 variants are currently underway in our laboratory.