Evaluation of the Nimbamrithadhi Panchathiktha Kashayam against SARS CoV-2 based on Network Pharmacology and Molecular Docking analysis.

BACKGROUND: Nimbamrithadhi Panchathiktha Kashayam (NPK) is an Ayurvedic formulation of potent plant ingredients with immune-modulating effects and anti-viral activities. OBJECTIVES: The present study is intended to identify the key target involved in immune and inflammatory response against SARS-CoV-2 via network pharmacology and also investigates the potent phytoconstituent within NPK in combating or modulating target response via molecular docking. METHODS: Active phytoconstituents of NPK were filtered based on overall bioavailability and drug-likeness by Lipinski's and ADMETOX prediction. RESULTS: Results indicate that IRF 7 can be selected as an efficient target in regulating immunomodulatory and anti-viral activity via network pharmacology. Molecular docking studies show that apigenin (22.22 Kcal /mol), thiamine (24.89 Kcal /mol) and esculetin (25.21 Kcal /mol) within Nimbamrithadhi Panchathiktha Kashayam(NPK) possess better binding affinity in comparison with standard drug gemcitabine (14.56 Kcal /mol). Even though docking score is more for Esculetin and Thiamine, Apigenin within Solanum Virgianum (Yellow nightshade) and Azadirachta Indica (Neem) is considered as the active phytoconstituent in modulating immune responses and anti-viral activities based on the number and nature of amino acid interaction. CONCLUSION: To the best of our knowledge, no scientific validation has been done on NPK against COVID-19. The study indicates that NPK can be a better alternative prophylaxis strategy against SARS-COV-2 infection if further validated via suitable preclinical studies.

Identification of Kaempferol as Viral Entry Inhibitor and DL-Arginine as Viral Replication Inhibitor from Selected Plants of Indian Traditional Medicine against COVID-19: An in silico Guided in vitro Approach.

BACKGROUND: Indian traditional medicinal plants are known for their great potential in combating viral diseases. Previously, we reported a systematic review approach of seven plausible traditional Indian medicinal plants against SARS-CoV-2. METHODS: Molecular docking was conducted with Biovia Discovery Studio. Three binding domains for spike glycoprotein (PDB IDs: 6LZG, 6M17, 6M0J) and one binding domain of RdRp (PDB ID: 7BTF) were used. Among 100 phytoconstituents listed from seven plants by the IMPPAT database used for virtual screening, the best six compounds were again filtered using Swiss ADME prediction and Lipinski's rule. Additionally, a pseudovirion assay was performed to study the interaction of SARS-CoV-2 S1-protein with the ACE 2 receptor to further confirm the effect. RESULTS: Chebulagic acid (52.06 Kcal/mol) and kaempferol (48.84 Kcal/mol) showed increased interaction energy compared to umifenovir (33.68 Kcal/mol) for the 6LZG binding domain of spike glycoprotein. Epicatechin gallate (36.95 Kcal/mol) and arachidic acid (26.09 Kcal/mol) showed equally comparable interaction energy compared to umifenovir (38.20 Kcal/mol) for the 6M17 binding domain of spike glycoprotein. Trihydroxychalcone (35.23 Kcal/mol) and kaempferol (36.96 Kcal/mol) showed equally comparable interaction energy with umifenovir (36.60 Kcal/mol) for 6M0J binding domain of spike glycoprotein. Upon analyzing the phytoconstituents against RdRp binding domain, DL-arginine (41.78 Kcal/mol) showed comparable results with the positive control remdesivir (47.61 Kcal/mol). ADME analysis performed using Swiss ADME revealed that kaempferol and DL arginine showed drug-like properties with appropriate pharmacokinetic parameters. Further in vitro analysis of kaempferol by pseudovirion assay confirmed an acceptable decrease of the lentiviral particles in transfected HEK293T-hACE2 cells. CONCLUSION: The study highlights that kaempferol and DL-arginine could be the significant molecules to exhibit potent action against SARS-CoV-2 and its variants.

2,4-Dihydroxycinnamic acid as spike ACE2 inhibitor and apigenin as RdRp inhibitor in Nimbamritadi Panchatiktam Kashayam against COVID-19: an in silico and in vitro approach.

Nimbamritadi Panchatiktam Kashayam (NPK) is an ayurvedic formulation composed of ingredients with potent anti-viral activities. We studied the interaction energy of 144 phytoconstituents present in NPK against spike receptor-binding domain (RBD) complexed with ACE2 protein (PDB ID: 6LZG) and RNA-dependent RNA polymerase protein (PDB ID: 7BTF) using Biovia Drug Discovery studio. The result indicated that 2,4-hydroxycinnamic acid exerts more significant binding affinities (28.43 kcal/mol) than Umifenovir (21.24 kcal/mol) against spike ACE2. Apigenin exhibited the highest binding affinities (54.63 kcal/mol) compared with Remdesivir (24.52 kcal/mol) against RdRp. An in vitro analysis showed a reduction in the number of lentiviral particles on transfected HEK293T-hACE2 cells as assessed by pseudovirus inhibition assay. At the same time, the tested compounds showed non-toxic up to 100 µg/ml in normal cells by MTT assay. The study highlights the plausible clinical utility of this traditional medicine against SARS CoV2.