In silico and in vitro studies on inhibitors for SARS-CoV-2 non-structural proteins with dual herbal combination of Withania somnifera with five rasayana herbs.

Being highly transmissible, severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected millions of people causing devastating global impact and has also not slowed down even after vaccination. The emerges of new strains has made more concerns than the original one. We need a new therapeutic approach against the disease. Our comprehensive in silico study investigates dual herbal combinatorial methanolic extracts of W. somnifera (W) alone and with P. emblica (P) (W:P/1:4) , T. sinensis (T) (W:T/1:4), B. monnieri (B) (W:B/1:1), O. basilicum (O) (W:O/1:4), A. racemosus (A) (W:A/4:1) for potential four phytochemicals as ligands docked with eight COVID-19 Nonstructural proteins (nsp)-main protease (PDB ID:6LU7), papain-like protease (6WUU), helicase ADP (2XZL), N7-methyltransferase (5C8S), endoribonuclease (6WLC), 2'O-methyltransferase (6WVN), RNA dependent RNA polymerase (6M71), and 3Cprotease (6YNQ) along with Remdesivir and Hydroxychloroquine. Ligands from W:P/1:4 showed remarkable docking score (-9.01 kcal/mol) 6M71-(8E,11E,14E)-eicosa-8,11,14-trienoicacidmethylester (EIS) and (-9.99 kcal/mol) 6YNQ-N-[(E)-[4-[(2-methoxydibenzofuran-3-yl)amino]-4-oxobutan-2-ylidene]amino] 4nitrobenzamide (MET). Further, MD simulations were studied for 100 ns and showed the complexes were flexible, stable in the binding pockets of the receptors, and MM-PBSA analysis determined high binding energy of -129.673 ± 15.284 and -134.594 ± 7.085 for 6M71-EIS (Asn496, Lys577, Arg569) and 6YNQ-MET (Cys145, His41). Finally, in vitro JURKAT E6.1 cell lines treated with W:P/1:4 and W:O/1:4 methanolic extracts yielded 44.06 and 31.53 ng/mL levels for interferon alpha to counteract an external stimulus by establishing an antiviral state. Thus, nsp is targeted to design effective antiviral drugs for developing an effective therapeutic approach to combat viral RNA synthesis, processing, and suppression of host immunity.Communicated by Ramaswamy H. Sarma.

Dual herbal combination of Withania somnifera and five Rasayana herbs: A phytochemical, antioxidant, and chemometric profiling.

BACKGROUND: Traditional medicine adequately emphasis plant resources for addressing a wide variety of human ailments by utilizing the naturally occurring phytoconstituents; in particular medicinal plants or parts of plants in combination have prodigious antioxidant potentials. OBJECTIVE: The present study aims to analyze methanolic extract of W. somnifera (W) individually, and in dual combination with five Rasayana herbs P. emblica - (W:P), B. monnieri - (W:B), T. sinensis - (W:T), O. basilicum - (W:O), A. racemosus - (W:A) in three dual ratios [4:1, 1:1, and 1:4]. The efficacy of the combinations is assessed based on their chemometric profiling. MATERIAL AND METHODS: A total of 15 dual combinatorial methanolic extracts together with W. somnifera were evaluated for their preliminary phytochemical profiles, antioxidant potentials using DPPH and FRAP assays. Five dual samples were selected and analyzed for High-Performance Thin-Layer Chromatography (HPTLC) image-based chemometric profiling followed by Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA)-Heatmaps. RESULTS: Qualitative phytochemical analysis of combinatorial extracts exhibited a richness for a variety of phytoconstituents. The antioxidant activity was significantly higher for DPPH IC50 (µg/mL): W = 11.56 ± 3.69; W:P/1:4 = 7.89 ± 1.52; W:O/1:4 = 8.995 ± 2.64 and FRAP (µM FeE/g): W = 4.56 ± 0.54; W:P/1:4 = 138.34 ± 9.25; W:O/1:4 = 15.32 ± 1.64. Chemometric data acquisition displayed improved secondary metabolite close cluster combination with W:O/1:4 and W:P/1:4 than W. somnifera (W) alone. CONCLUSION: The dual herbal combinatorial study revealed that the methanolic combinatorial extracts phytoconstituents correlated with an increase in the antioxidant potential and would serve as a promising source for phytomedicine.