Pharmacokinetics and molecular docking study of siddha polyherbal preparation shailam against COVID-19 mutated S gene

ABSTRACT

COVID-19 is a deadly disease;at the time of the first COVID-19 wave (January 2020 to November 2020), so many deaths were reported worldwide. There were no standard conventional treatments and vaccines, so the whole world turned to traditional medicine. Siddha system of medicine is one of the traditional medicines practiced in the southern part of India. Shailam is a polyherbal formulation (licence no. 1189/25D) which was analyzed by molecular docking, with AutoDockVina software, against SARS-CoV-2 Spike Protein (PDB ID 7DDD). Absorption, distribution, metabolism, and excretion (ADME) properties were also recorded for Shailams phytocompounds using the online SwissADME tool. The results of the molecular docking study showed that the phytocompounds, like Caryophyllene, Aspidospermidin-17-ol, N,N Dibenzylidene-3,3-dichlorobenzidine, Beta-selinene, Curzerene, Germacrene B, Spathulenol, had the highest docking scores -6.6 Kcal/mol, -8.8 Kcal/mol, -8.7 Kcal/mol, -6.2 Kcal/mol, -6.0 Kcal/mol, -6.6 Kcal/mol, -6.5 Kcal/mol, respectively, and the scores fall within the docking score range of the four standard conventional drugs;Azithromycin, Hydroxychloroquinone, Ivermectin, and Remdesivir which had binding energies of 7.7 Kcal/mol, -5.9 Kcal/mol, -9.2 Kcal/mol, and -7.5 Kcal/mol, respectively. ADME analysis predicted that all of Shailams phytocompounds met four Lipinskis rule of five and have a higher bioavailability score (0.55) as compared to standard conventional drugs, Azithromycin, Hydroxychloroquinone, Ivermectin, and Remdesivir (0.17). Twelve of Shailams phytochemical compounds have high GIT absorption and can cross the blood-brain barrier (BBB). In conclusion, Shailams phytocompounds show a good docking score and ADME property against SARS-CoV-2 Spike Protein (PDB ID 7DDD) as compared to standard conventional drugs.