Phytonutrient Inhibitors of SARS-CoV-2/NSP5-Encoded Main Protease (Mpro) Autocleavage Enzyme Critical for COVID-19 Pathogenesis.

The genomic reshuffling, mutagenicity, and high transmission rate of the SARS-CoV-2 pathogen highlights an urgent need for effective antiviral interventions for COVID-19 control. Targeting the highly conserved viral genes and/or gene-encoded viral proteins such as main proteinase (Mpro), RNA-dependent RNA polymerase (RdRp) and helicases are plausible antiviral approaches to prevent replication and propagation of the SARS-CoV-2 infection. Coronaviruses (CoVs) are prone to extensive mutagenesis; however, any genetic alteration to its highly conserved Mpro enzyme is often detrimental to the viral pathogen. Therefore, inhibitors that target the Mpro enzyme could reduce the risk of mutation-mediated drug resistance and provide effective antiviral protection. Several existing antiviral drugs and dietary bioactives are currently repurposed to treat COVID-19. Dietary bioactives from three ayurvedic medicinal herbs, 18 ß-glycyrrhetinic acid (ΔG = 8.86 kcal/mol), Solanocapsine (ΔG = 8.59 kcal/mol), and Vasicoline (ΔG = 7.34 kcal/mol), showed high-affinity binding to Mpro enzyme than the native N3 inhibitor (ΔG = 5.41 kcal/mol). Flavonoids strongly inhibited SARS-CoV-2 Mpro with comparable or higher potency than the antiviral drug, remdesivir. Several tannin hydrolysates avidly bound to the receptor-binding domain and catalytic dyad (His41 and Cys145) of SARS-CoV-2 Mpro through H-bonding forces. Quercetin binding to Mpro altered the thermostability of the viral protein through redox-based mechanism and inhibited the viral enzymatic activity. Interaction of quercetin-derivatives with the Mpro seem to be influenced by the 7-OH group and the acetoxylation of sugar moiety on the ligand molecule. Based on pharmacokinetic and ADMET profiles, several phytonutrients could serve as a promising redox nutraceutical for COVID-19 management.

Targeting COVID-19 (SARS-CoV-2) main protease through active phytochemicals of ayurvedic medicinal plants - Withania somnifera (Ashwagandha), Tinospora cordifolia (Giloy) and Ocimum sanctum (Tulsi) - a molecular docking study.

COVID-19 (Coronavirus disease 2019) is a transmissible disease initiated and propagated through a new virus strain SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) since 31st December 2019 in Wuhan city of China and the infection has outspread globally influencing millions of people. Here, an attempt was made to recognize natural phytochemicals from medicinal plants, in order to reutilize them against COVID-19 by the virtue of molecular docking and molecular dynamics (MD) simulation study. Molecular docking study showed six probable inhibitors against SARS-CoV-2 Mpro (Main protease), two from Withania somnifera (Ashwagandha) (Withanoside V [10.32 kcal/mol] and Somniferine [9.62 kcal/mol]), one from Tinospora cordifolia (Giloy) (Tinocordiside [8.10 kcal/mol]) and three from Ocimum sanctum (Tulsi) (Vicenin [8.97 kcal/mol], Isorientin 4'-O-glucoside 2″-O-p-hydroxybenzoagte [8.55 kcal/mol] and Ursolic acid [8.52 kcal/mol]). ADMET profile prediction showed that the best docked phytochemicals from present work were safe and possesses drug-like properties. Further MD simulation study was performed to assess the constancy of docked complexes and found stable. Hence from present study it could be suggested that active phytochemicals from medicinal plants could potentially inhibit Mpro of SARS-CoV-2 and further equip the management strategy against COVID-19-a global contagion. HighlightsHolistic approach of Ayurvedic medicinal plants to avenge against COVID-19 pandemic.Active phytoconstituents of Ayurvedic medicinal plants Withania somnifera (Ashwagandha), Tinospora cordifolia (Giloy) and Ocimum sanctum (Tulsi) predicted to significantly hinder main protease (Mpro or 3Clpro) of SARS-CoV-2.Through molecular docking and molecular dynamic simulation study, Withanoside V, Somniferine, Tinocordiside, Vicenin, Ursolic acid and Isorientin 4'-O-glucoside 2″-O-p-hydroxybenzoagte were anticipated to impede the activity of SARS-CoV-2 Mpro.Drug-likeness and ADMET profile prediction of best docked compounds from present study were predicted to be safe, drug-like compounds with no toxicity.Communicated by Ramaswamy H. Sarma.

Incretin hormones receptor signaling plays the key role in antidiabetic potential of PTY-2 against STZ-induced pancreatitis.

AIMS: Incretin therapy is one of the most potential approaches in the treatment of diabetes. In contrast to markedly available drugs, the herbal incretin modulators have lesser side effects with low economic cost. The main aim of this work was to analyze the potential of previously reported DPPIV inhibitor, aqueous extract of Pueraria tuberosa tubers (PTY-2) as incretin hormones receptor agonist against streptozotocin (STZ)-induced diabetes. METHODS: Chronic diabetes was induced with STZ (65mg/kg bw) in rats for 60days and grouped into diabetic control and PTY-2. Expression of genes was assessed by PCR, IHC, and ELISA. Morphological analysis of tissue was observed using H & E stain. In silico molecular docking approach has been used to see the interaction of active phytochemicals of PTY-2 on the basis of their binding energy [kcal/mol] and dissociation constant [pM] using YASARA software. Interactive visualization was done using Discovery studio 3.0. RESULTS: In comparison to diabetic control, the size and number of islet cells along with the plasma level of GLP-1, GIP, and pancreatic expressions of GLP-1R, GIP-R, Bcl2, and insulin were enhanced significantly after PTY-2 treatment. Through in silico molecular docking, tuberostan showed the best interaction for GLP-1R with binding energy at 8.15kcal/mol and dissociation constant at 1061624.125 pM. Puererone showed the best interaction for GIP-R with binding energy at 8.31kcal/mol and dissociation constant at 810381 pM. CONCLUSIONS: In addition to previously studied DPPIV inhibitor, PTY-2 also acts as incretin receptors agonist and protects against STZ-induced diabetes by down regulating ß cells apoptosis.

Epilithonimonas ginsengisoli sp. nov., isolated from soil of a ginseng field.

A novel Gram-staining-negative, rod-shaped bacterium, designated DCY78(T), was isolated from soil of a ginseng field in Yeon-cheon province (38° 04' 00″ N 126° 57' 00″ E), Republic of Korea. The phylogenetic analysis based on 16S rRNA gene sequences showed that strain DCY78(T) belonged to the genus Epilithonimonas and was most closely related to Epilithonimonas lactis DSM 19921(T) (98.5 % sequence similarity) and Epilithonimonas tenax DSM 16811(T) (97.8 %). Growth occurred at 10-30 °C with an optimum temperature of 28 °C. The pH range for growth was pH 5.5-8.0. The major polar lipids were found to be phosphatidylethanolamine three unidentified amino lipids and one unidentified polar lipid. The only predominant quinone was MK-6. The major polyamines were sym-homospermidine and spermidine. The major fatty acids were summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c), iso-C15 : 0 and iso-C17 : 0 3-OH. The DNA G+C content was 37.9 mol%. On the basis of the phenotypic and genotypic analysis, the isolate is classified as representative of a novel species in the genus Epilithonimonas, for which the name Epilithonimonas ginsengisoli is proposed. The type strain is DCY78(T) ( = KCTC 32174(T) = JCM 19896(T)).

Phenethyl isothiocyanate inhibits 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory responses in mouse skin.

Phenethyl isothiocyanate (PITC) is the hydrolysis product of the glucosinolate gluconasturtiin in cruciferous vegetables. This study was conducted to determine whether PITC inhibits 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in the mouse ear. Topical application of 5 nmol of TPA to mouse ears markedly increased the ear weight, expression of the inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 protein, and phosphorylation of the inhibitor of κB (IκB) α, AKT, and extracellular signal-regulated protein kinase (ERK) 1/2 and reduced IκBα protein levels. Pretreatment with PITC (150-450 nmol) significantly suppressed these TPA-induced inflammatory responses. We also determined whether low concentrations of PITC (0.5-5 µmol/L) inhibited lipopolysaccharide (LPS)-stimulated inflammatory responses in Raw264.7 cells. PITC dose-dependently reduced the LPS-induced secretion of nitric oxide, prostaglandin E(2), interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α, as well as COX-2 and iNOS protein expression. PITC also attenuated LPS-induced increases in iNOS, COX-2, IL- 6, IL-1ß, and TNF-α mRNA levels, as well as the promoter-dependent transcriptional activation of the genes for iNOS and COX-2. PITC inhibited LPS-induced IκBα phosphorylation and degradation and subsequently reduced LPS-induced p65 nuclear translocation and the transcriptional activity of nuclear factor-κB (NF-κB), which was accompanied by a reduction in ERK1/2 and AKT phosphorylation. The results of this study demonstrated that PITC effectively inhibits inflammatory responses in vivo and in vitro, which may be mediated via the inhibition of AKT and ERK1/2 activation, leading to subsequent inhibition of the transcriptional activity of NF-κB.