Integrating in-vitro experiments and in-silico approaches identified antiviral activity of black mulberry (Morus nigra) as a potential treatment option for SARS-CoV-2

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), belongs to β-coronavirus, responsible of coronavirus disease-2019 pandemic (COVID-19), claiming roughly 4.9 million lives worldwide. Currently, there's no specific therapy for the disease. Infection begins with the Spike glycoprotein binding to ACE2 (angiotensin-converting enzyme 2) receptors. The study aimed to identify potential inhibitors against the Spike protein of SARS-CoV-2 from rue herb and black mulberry extracts through molecular docking and in-vitro assays. It screened 53 compounds from rue herb and 11 from black mulberry (Morns nigra) using molecular docking and ADMET approaches. Docking simulations identified two compounds including Amentoflavone and Daphnoretin from rue herb, and Vitamin P and Pectin from black mulberry as potential inhibitors against the S protein that has binding energy -8.9, -8.2, -8.1, and -8.0 kcal/mol, respectively. ADMET analysis indicated good pharmacokinetics and toxicity profiles. Extracts of rue herb and black mulberry demonstrate inhibition against SARS-CoV-2 with IC50= 1.32 and 0.99 mg/ml, respectively, indicating potent activity. The selectivity index (SI) values of 9.55 and 25.48 for rue herb and black mulberry shrub extract respectively indicate good antiviral properties of mulberry shrub extract. Therefore, compounds such as Vitamin P and Pectin could be promising for treating or preventing SARS-CoV-2 disease-related complications.