Phytochemical Screening of Adathodai Kudineer a Siddha Concoction and Evaluation of Binding Affinity of Its Constituents with SARS-CoV-2 Spike Protein and ACE2 Receptor Spike Protein Complex Through Molecular Docking In-Silico Approach

Abstract

Siddha system of medicine has a great resource of potent drugs used to combat the flu like fevers indicated as Kabam suram and Visha suram. COVID 19 outbreak has thrown up the biggest challenge during recent times to the medical professionals and researchers to counter the disease condition effectively. Adathodai kudineer (AK) a Classical Siddha formulation is prescribed by Siddha Physicians to treat various fevers and other conditions that cause moderate to severe respiratory symptoms. In Siddha texts, it is mentioned to treat diseases that cause symptoms like cough, cold, dyspnea, loss of appetite etc., GC-MS analysis was carried out to identify the presence of potent lead molecules in AK. The aqueous extract has shown the following bioactive compounds such as Napthalene, Benzene Propanol, Benzene Acetic Acid, Furazan-3-amine, Pyrazol-4-Carboxylic acid and 2(3H) Furanone. The ethanolic extract of AK exhibited the molecular compounds such as Eucalyptol, Toluene, 2-Carene, Copaene, Alpha-Copaene, 1,6-Cyclodecadiene, Alloaromadendrene, Aromadendrene, Gamma-muurolene, Beta-copaene, Cubebol, Selina-3,7 (11) - Diene, 2-Butanone. Molecular docking is a powerful approach in current trends to identify the possibility of pharmacological effects of medicinal compounds which could be exerted over their Corresponding Protein targets which are relevant for causing disease. Using Autodock Vina Software the biomolecules of AK were analyzed through molecular docking against SARS-CoV-2 Spike Protein (PDB ID 6LU7) and SARS-CoV-2 Spike Protein – ACE 2 receptor complex (6LZG). ADME properties were also recorded for the aqueous and ethanolic extracts of AK compounds using online tool SWISS ADME. The binding energy observed were of the order: -10.9 Kcal/mol, -8.0 Kcal/mol, -7.8 Kcal/mol for the compounds Alpha-Copaene, Gamma-Muurolene, Selina-3,7 (11)–Diene respectively towards the protein targets 6LZG and -8.2 Kcal/mol, -6.6 Kcal/Mol, -6.5 Kcal/Mol, for the compounds Alpha-Copaene, Cubebol and Aromadendrene respectively towards the target 6LU7. These findings suggest that the Siddha formulation Adathodai Kudineer (AK) has possibly potent activity against SARS-CoV-2 Virus causing the COVID19 disease. Furthermore, in-vitro studies have to be validated through investigation in cell lines towards the possible role of efficacy of AK against the COVID19 pathogen.