Anti-SARS-CoV-2 <i>in vitro</i> potential of castor oil plant (<i>Ricinus communis</i>) leaf extract: <i>in-silico</i> virtual evidence
Rawah H. Elkousy, Zeinab Nabil Ahmed Said, Mohamed A. Ali, Omnia Kutkat, Salwa A. Abu El Wafa
Abstract
Abstract Ricinus communis L. is a medicinal plant that displays valuable pharmacological properties, including antioxidant, antimicrobial, analgesic, antibacterial, antiviral and anti-inflammatory properties. This study targeted to isolate and identify some constituents of R. communis leaves using ultra-performance liquid chromatography coupled with mass spectroscopy (UPLC-MS/MS) and different chromatographic techniques. In vitro anti-MERS and anti-SARS-CoV-2 activity for different fractions and for two pure isolated compounds, lupeol (RS) and ricinine (RS1) were evaluated using a plaque reduction assay with three different mechanisms and IC 50 based on their cytotoxic concentration (CC 50 ) from an MTT assay using Vero E6 cell line. Isolated phytoconstituents and remdesivir are assessed for in-silico anti-COVID-19 activity using molecular docking tools. The methylene chloride extract showed pronounced virucidal activity against SARS-CoV-2 (IC 50 = 1.76 μg/ml). It was also shown that ricinine had superior potential activity against SARS-CoV-2, (IC 50 = 2.5 μg/ml). Lupeol displayed the most potency against MERS, (IC 50 = 5.28 μg/ml). Ricinine appeared to be the most biologically active compound. The study showed that R. communis and its isolated compounds have potential natural virucidal activity against SARS-COV-2; however, additional exploration is necessary and study for their in vivo activity.