Molecular Docking Investigation of Antiviral Herbal Compounds as Potential Inhibitors of SARS-CoV-2 Spike Receptor

At the beginning of 2020, a new type of Coronavirus (Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2)) dismayed the world and led to public health emergencies. This virus has caused a remarkable percentage of morbidity and mortality. Also, the lack of an effective treatment to fight this virus is another concern that should be given attention. Herbal medicines and purified natural products have been reported for their antiviral activity against SARS-CoV-2. In this study, molecular docking of effective compounds in the extracts and essential oils of Zingiber officinale, Glycyrrhiza glabra Sambucus nigra, Panax ginseng Ocimum basilicum, and Origanum vulgare was carried out to investigate their binding to the X-ray structure of the ACE2 binding domain of SARS-CoV-2. The Glide docking program was utilized for molecular docking with standard precision (SP) and extra precision (XP). Finally, 7 compounds-mainly belong to Panax ginseng-showed a higher docking score than some known antiviral compounds. Floralginsenoside B, which is extracted from Panax ginseng, indicated a strong binding affinity (-8.618 kcal/mol) to the crucial residues of the receptor binding domain of SARS-CoV-2 comparing to Doravirine (-7.2 kcal/mol), Hetacillin (-7.1 kcal/mol), Ketoprofen (-7.0 kcal/mol), and Mefloquine (-7.0 kcal/mol) reported in previous articles. Based on the excellent binding affinities of these herbal compounds, we concluded that these phytochemicals could be promising candidates for fighting against the COVID-19 pandemic.