Molecular Docking Studies of Bioactive Nicotiflorin against 6W63 Novel Coronavirus 2019 (COVID-19)

Selenium-enriched peptides identified from selenium-enriched soybean protein hydrolysate: protective effects against heat damage in Caco-2 cells

Our previous study evaluated the antioxidant and anti-inflammatory activities of selenium-enriched soybean peptides (SePPs) in vivo. In this study, we purified SePPs via gel filtration chromatography and obtained five fractions (F1, F2, F3, F4 and F5), among which F3 displayed the highest antioxidant and anti-inflammatory activities. Nineteen selenium-enriched peptides were identified in F3 by mass spectrometry. Two selenium-enriched peptides with sequences ESeCQIQKL (Sep-1) and SELRSPKSeC (Sep-2) were selected for synthesis based on their score and the number of hydrophobic amino acids, acidic and basic amino acids. Both Sep-1 and Sep-2 exhibited preventive effects on the heat stress-induced impairment of intestinal epithelial cell integrity, oxidative stress and inflammatory responses in a Caco-2 cell model. Pretreatment of the cells with Sep-1 or Sep-2 for 24 h reduced intracellular reactive oxygen species (ROS) generation, prevented the disruption of tight junction (TJ) proteins, and decreased paracellular permeability. Western blot results showed that Sep-1 and Sep-2 could improve the abnormal expressions of Nrf2, Keap1, NLRP3, caspase-1 and ASC/TMS1, thereby enhancing the glutathione (GSH) redox system and reducing IL-1β and IL-18 concentrations. Sep-1 activated the Nrf2-Keap1 signaling pathway significantly more than Sep-2. Molecular docking results indicated that Sep-1 and Sep-2 are both bound to Keap1 and NLRP3 in the form of hydrogen bonds, hydrophobic interactions and salt bridges, which interferes with Nrf2 and NLRP3 signaling. Molecular dynamics simulations suggested that more hydrogen bonds were formed during the resultant process of Sep-1 with Keap1, and the compactness and stability of the complex structure were better than those of Sep-2. These findings confirm the value of both Sep-1 and Sep-2 in the development of dietary supplements as potential alternatives for heat damage and related disease prevention.

Metabolic bioprofiling of different Glycyrrhiza glabra solvent fractions for the identification of anti-adenoviral compounds using LC-HRMS/MS and in-vitro cytopathic assay coupled with chemometry

Human adenovirus type-7 (HAdV-7) is a common pathogen that may cause significant morbidity as well as severe complications. Currently, there is no approved drug for the treatment of HAdV-7 infections and the contemporary strategy mainly rely on nonspecific antivirals. Glycyrrhiza glabra; (licorice), is a well-recognized edible plant used in food and beverages. The plant is renowned for its pharmacological and biological activities including antiviral activities against wide range of viruses. The following study reported for the first time the anti-adenoviral activity of licorice extract using in-vitro cytopathic inhibitory assay. Different solvent fractions showed promising activity with IC₅₀ reaching 1.431 μg/ml. Certain fractions had selectivity index (SI) greater than 10 indicating their efficacy together with relatively low cytotoxic effect. Metabolic profiling using LC-HRMS/MS resulted in identification of 41 compounds from licorice fractions. Chemometric modeling using Orthogonal Projections to Latent Structures (OPLS) suggested the compounds; kaempferol-3-O-rutinoside, violanthin, rhamnoliquiritin, isoliquiritigenin isomer, licoagroside B and liquiritin apioside as potential markers against (HAdV-7). Finally, kaempferol-3-O-rutinoside was further confirmed via in-vitro adenovirus inhibitory assay to possess strong antiviral activity with IC₅₀ and CC₅₀ of 54.7 ± 1.93 μM and 655.7 ± 2.22 μM, respectively.

Kaempferol-3-O-rutinoside exerts cardioprotective effects through NF-κB/NLRP3/Caspase-1 pathway in ventricular remodeling after acute myocardial infarction

Ventricular remodeling (VR) after acute myocardial infarction (AMI) is the main pathogenesis of chronic heart failure (CHF). Kaempferol-3-O-rutinoside (KR) is the flavonoid glycoside with the highest content in Lu'an GuaPian tea, which has good pharmacological activities. However, the mechanism of KR against VR after AMI remains unclear. Molecular docking was used to predict the targets of KR on the NLRP3/Caspase-1 signaling pathway. Histological changes in the myocardium were visualized using HE staining, Masson staining. Cardiomyocyte apoptosis was detected using TUNEL. Immunohistochemistry was used to examine NLRP3, Caspase-1 p20, and GSDMD. IL-1β level in serum was detected using ELISA. Finally, the expressions of NF-κB p65, NLRP3, ASC, Caspase-1 p20, GSDMD, and IL-1β were measured using RT-PCR and Western blotting. Our results showed that KR had a good binding activity with NLRP3, Caspase-1, and GSDMD, significantly improved cardiac function, alleviated cardiac pathological changes, reduced the excessive deposition of myocardial interstitial collagen, and inhibited cardiomyocyte apoptosis in AMI rats. Furthermore, KR could decrease the IL-1β level and inhibit the expressions of NF-κB p65, NLRP3, ASC, Caspase-1 p20, GSDMD, and IL-1β. Our study suggests that KR can prevent and treat VR after AMI, and the protective effect is related to its regulatory NF-κB/NLRP3/Caspase-1 signaling pathway. PRACTICAL APPLICATIONS: Kaempferol-3-O-rutinoside is present in Carthamus tinctorius L., Nymphaea candida, Afgekia mahidoliae and green tea, which has good pharmacological activities against liver injury, cerebral ischemia/reperfusion injury, dementia, hyperglycemia, and myocardial infarction. Our previous study found that kaempferol-3-O-rutinoside had an obvious anti-inflammatory effect, and could significantly improve the cell survival rate of H9c2 myocardium inflammatory injury induced by LPS. In this study, kaempferol-3-O-rutinoside significantly improved cardiac function, alleviated cardiac pathological changes, reduced the excessive deposition of myocardial interstitial collagen, and inhibited cardiomyocyte apoptosis in AMI rats. Furthermore, kaempferol-3-O-rutinoside could decrease the IL-1β level and inhibit the expressions of NF-κB p65, NLRP3, ASC, Caspase-1, GSDMD and IL-1β, suggesting that kaempferol-3-O-rutinoside could regulate NF-κB/NLRP3/Caspase-1 signaling pathway.

Discovery of Bispecific Lead Compounds from Azadirachta indica against ZIKA NS2B-NS3 Protease and NS5 RNA Dependent RNA Polymerase Using Molecular Simulations

Zika virus (ZIKV) has been characterized as one of many potential pathogens and placed under future epidemic outbreaks by the WHO. However, a lack of potential therapeutics can result in an uncontrolled pandemic as with other human pandemic viruses. Therefore, prioritized effective therapeutics development has been recommended against ZIKV. In this context, the present study adopted a strategy to explore the lead compounds from Azadirachta indica against ZIKV via concurrent inhibition of the NS2B-NS3 protease (ZIKV^pro) and NS5 RNA dependent RNA polymerase (ZIKV^RdRp) proteins using molecular simulations. Initially, structure-based virtual screening of 44 bioflavonoids reported in Azadirachta indica against the crystal structures of targeted ZIKV proteins resulted in the identification of the top four common bioflavonoids, viz. Rutin, Nicotiflorin, Isoquercitrin, and Hyperoside. These compounds showed substantial docking energy (−7.9 to −11.01 kcal/mol) and intermolecular interactions with essential residues of ZIKV^pro (B:His⁵¹, B:Asp⁷⁵, and B:Ser¹³⁵) and ZIKV^RdRp (Asp⁵⁴⁰, Ile⁷⁹⁹, and Asp⁶⁶⁵) by comparison to the reference compounds, O7N inhibitor (ZIKV^pro) and Sofosbuvir inhibitor (ZIKV^RdRp). Besides, long interval molecular dynamics simulation (500 ns) on the selected docked poses reveals stability of the respective docked poses contributed by intermolecular hydrogen bonds and hydrophobic interactions. The predicted complex stability was further supported by calculated end-point binding free energy using molecular mechanics generalized born surface area (MM/GBSA) method. Consequently, the identified common bioflavonoids are recommended as promising therapeutic inhibitors of ZIKV^pro and ZIKV^RdRp against ZIKV for further experimental assessment.

Medicinal Importance, Pharmacological Activities and Analytical Aspects of a Flavonoid Glycoside 'Nicotiflorin' in the Medicine

BACKGROUND

Herbal products are derived from different natural sources, mainly used as a source of food material and medicine in the health sectors since ancient times. Herbal products have gained popularity in modern medicine due to their beneficial health properties and pharmacological activities. Flavonoids are an important class of secondary metabolites found to be present in medicinal plants and their derived products. Flavonoids have been known for their anti-allergic, anti-bacterial, anti-diabetic, anti-inflammatory, anti-viral, anti-proliferative, anti-mutagenic, antithrombotic, anti-carcinogenic, anti-oxidant and hepatoprotective activities in the medicine. Nicotiflorin is a flavonoidal class phytochemical, found in medicinal plants, including Traditional Chinese medicine.

METHODS

Scientific data on the medicinal importance and pharmacological activities of nicotiflorin have been collected and analyzed in the present work in order to know the therapeutic importance of nicotiflorin in medicine. Scientific data have been collected from Google, Google Scholar, Science Direct, PubMed and Scopus and analyzed in the present work. Analytical techniques data of separation, isolation and identification of nicotiflorin have also been collected and presented in the current work. Further biological importance of flavonoidal class phytochemicals was also discussed in the present work to understand the biological importance of nicotiflorin in medicine as it belongs to the flavonoid class.

RESULTS

Scientific data analysis revealed the therapeutic importance and pharmacological activities of nicotiflorin. Nicotiflorin has significant biological potential against coronavirus, ischemia, renal impairment, hepatic complication, memory dysfunction and myocardial infarction. The biological potential of nicotiflorin against α-glucosidase and α-amylase enzymes, multiple myeloma cells and insulin secretion has also been discussed in the present work. Analytical data revealed the significance of modern analytical tools in medicine for the isolation, separation and quantification of nicotiflorin.

CONCLUSION

Scientific data analysis of different research works revealed the biological importance and therapeutic potential of nicotiflorin in medicine.

Coumarins and Quinolones as Effective Multiple Targeted Agents Versus Covid-19: An in Silico Study

BACKGROUND

The Covid-19 virus emerged a few months ago in China and infections rapidly escalated into a pandemic.

OBJECTIVE

To date, there is no selective antiviral agent for the management of pathologies associated with covid-19 and the need for an effective agent against it is essential.

METHOD

In this work two home-made databases from synthetic quinolines and coumarins were virtually docked against viral proteases (3CL and PL), human cell surface proteases (TMPRSS2 and furin) and spike proteins (S1 and S2). Chloroquine, a reference drug without a clear mechanism against coronavirus was also docked on mentioned targets and the binding affinities compared with title compounds.

RESULT

The best compounds of synthetic coumarins and quinolines for each target were determined. All compounds against all targets showed binding affinity between -5.80 to -8.99 kcal/mol in comparison with the FDA-approved drug, Chloroquine, with binding affinity of -5.7 to -7.98 kcal/mol. Two compounds, quinoline-1 and coumarin-24, were found to be effective on three targets - S2, TMPRSS2 and furin - simultaneously, with good predicted affinity between -7.54 to -8.85 kcal/mol. In silico ADME studies also confirmed good oral absorption for them. Furthermore, PASS prediction was calculated and coumarin-24 had higher probable activity (Pa) than probable inactivity (Pi) with acceptable protease inhibitory as well as good antiviral activity against Hepatitis C virus (HCV), Human immunodeficiency virus (HIV) and influenza.

CONCLUSION

Quinoline-1 and Coumarin-24 have the potential to be used against Covid-19. Hence these agents could be useful in combating covid-19 infection after further in vitro and in vivo studies.