## 4 Discussion
Acteoside and verbascoside from _C. serratum_ act well against the MT-NTD. Acteoside holds eight hydrogen bonds, one alkyl, and three hydrophobic interactions with \(-7.3\) kcal/mol of binding affinity. Moreover, verbascoside shows seven hydrogen bonds, two alkyl bonds, one pi-sigma bond, and three hydrophobic interactions with the binding affinity of \(-7.1\) kcal/mol. These two phytocompounds have specifically interacted with the mutated residues GLN234. [PERSON] et al. reported that acteoside from _Tectona grandis_ acts effectively against SARS-CoV-2 proteases [149]. [PERSON] et al. reported that verbascoside from _Cichorium intybus_, _Olea europaea_, and _Marrubium vulgare_ acts as a potent anti-COVID-19 compound [150]. _H. cordata_ is implemented to treat many diseases related to the lungs, especially against viruses such the pseudorabies herpes virus (PrV), human noroviruses (HuNoVs), murine coronaviruses, and the dengue virus infection; regulate innate immune modulation activities positively, and also inhibit the replication of SARS-CoV [65, 91, 92, 93, 94, 95, 96, 97, 98]. Nevertheless, the ceftaxone constitutes less binding affinity \(-6.5\) kcal/mol, and it does not interact with the targeted residues L452R, T478K, and E484Q in the RBD. The compounds kanzonol V (\(-6.8\) kcal/mol), progeldanamycin (\(-6.4\) kcal/mol), and rhodoxanthin (\(-7.5\) kcal/mol) from _H. cordata_ act effectively against the target residues in the RBD of the Indian delta variant B.1.617.2 with better binding affinity. Even though kanzonol and rhodoxanthin violated one or two Lipinski rules, they beneficially treated bacterial and fungal infections, as previously reported [151]. Additionally, the toxicity class is satisfactorily categorized as V and VI for kanzonol V and rhodoxanthin. Progeldanamycin is not violating any rules, and its toxicity class is described as VI. In addition, [PERSON] et al. explained that violation of two or more Lipinski rules for the natural products and their derivatives is acceptable. However, the FDA-approved oral drugs under the category Class 1 (acarbose, cyanocobalamin, everolimus, ivermectin, etc.) are believed to have high solubility properties and high permeability, also violating the Lipinski rule [152]. Moreover, the maximum number of phytocompounds from _H. cordata_ and Kabasura kudineer act significantly well against the NTD and RBD domain of the Indian delta variant B.1.617.2 S-protein. AYUSH has recommended many treatments towards COVID-19 prevention, which are implemented as preventative and symptomatic therapy in COVID-19 management [153, 154]. Nevertheless, no Siddha formulation was prescribed for COVID-19 containing _H. cordata_, including Kabasura kudineer and Ayush kwath, which has already been recommended by the Indian government [60, 155]. According to the current investigation, the formulations and phytocompounds examined in this study showed considerably greater binding efficacy against the MT-NTD and RBD in the S-Protein of the Indian delta variant B.1.617.2. In silico studies suggested that the resulting phytocompounds may operate as efficient inhibitors of the Indian delta variant B.1.617.2 by binding to the spike glycoprotein, which may be investigated further in vitro to develop improved herbal formulations and anti-viral drugs. Furthermore, SARS-CoV-2 has been proven to have a greater affinity for pharyngeal epithelial cells [55]. Since these extracts can be delivered to the pharyngeal regions through appropriate oral formulations, they will be effective to control the infection rates.