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1.
Med Sci Monit ; 28: e934102, 2022 Jan 25.
Article in English | MEDLINE | ID: covidwho-1651076

ABSTRACT

BACKGROUND Heat-clearing and detoxifying herbs (HDHs) play an important role in the prevention and treatment of coronavirus infection. However, their mechanism of action needs further study. This study aimed to explore the anti-coronavirus basis and mechanism of HDHs. MATERIAL AND METHODS Database mining was performed on 7 HDHs. Core ingredients and targets were screened according to ADME rules combined with Neighborhood, Co-occurrence, Co-expression, and other algorithms. GO enrichment and KEGG pathway analyses were performed using the R language. Finally, high-throughput molecular docking was used for verification. RESULTS HDHs mainly acts on NOS3, EGFR, IL-6, MAPK8, PTGS2, MAPK14, NFKB1, and CASP3 through quercetin, luteolin, wogonin, indirubin alkaloids, ß-sitosterol, and isolariciresinol. These targets are mainly involved in the regulation of biological processes such as inflammation, activation of MAPK activity, and positive regulation of NF-kappaB transcription factor activity. Pathway analysis further revealed that the pathways regulated by these targets mainly include: signaling pathways related to viral and bacterial infections such as tuberculosis, influenza A, Ras signaling pathways; inflammation-related pathways such as the TLR, TNF, MAPK, and HIF-1 signaling pathways; and immune-related pathways such as NOD receptor signaling pathways. These pathways play a synergistic role in inhibiting lung inflammation and regulating immunity and antiviral activity. CONCLUSIONS HDHs play a role in the treatment of coronavirus infection by regulating the body's immunity, fighting inflammation, and antiviral activities, suggesting a molecular basis and new strategies for the treatment of COVID-19 and a foundation for the screening of new antiviral drugs.


Subject(s)
COVID-19/drug therapy , Coronavirus/drug effects , Drugs, Chinese Herbal/pharmacology , SARS-CoV-2/drug effects , Alkaloids/chemistry , Alkaloids/pharmacology , Caspase 3/drug effects , Caspase 3/genetics , Coronavirus/metabolism , Coronavirus Infections/drug therapy , Cyclooxygenase 2/drug effects , Cyclooxygenase 2/genetics , Databases, Pharmaceutical , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/therapeutic use , Flavanones/chemistry , Flavanones/pharmacology , Humans , Indoles/chemistry , Indoles/pharmacology , Interleukin-6/genetics , Lignin/chemistry , Lignin/pharmacology , Luteolin/chemistry , Luteolin/pharmacology , Mitogen-Activated Protein Kinase 14/drug effects , Mitogen-Activated Protein Kinase 14/genetics , Mitogen-Activated Protein Kinase 8/drug effects , Mitogen-Activated Protein Kinase 8/genetics , Molecular Docking Simulation , NF-kappa B p50 Subunit/drug effects , NF-kappa B p50 Subunit/genetics , Naphthols/chemistry , Naphthols/pharmacology , Nitric Oxide Synthase Type III/drug effects , Nitric Oxide Synthase Type III/genetics , Protein Interaction Maps , Quercetin/chemistry , Quercetin/pharmacology , SARS-CoV-2/metabolism , Signal Transduction , Sitosterols/chemistry , Sitosterols/pharmacology , Transcriptome/drug effects , Transcriptome/genetics
2.
J Virol ; 95(16): e0018721, 2021 07 26.
Article in English | MEDLINE | ID: covidwho-1486048

ABSTRACT

Subversion of the host cell cycle to facilitate viral replication is a common feature of coronavirus infections. Coronavirus nucleocapsid (N) protein can modulate the host cell cycle, but the mechanistic details remain largely unknown. Here, we investigated the effects of manipulation of porcine epidemic diarrhea virus (PEDV) N protein on the cell cycle and the influence on viral replication. Results indicated that PEDV N induced Vero E6 cell cycle arrest at S-phase, which promoted viral replication (P < 0.05). S-phase arrest was dependent on the N protein nuclear localization signal S71NWHFYYLGTGPHADLRYRT90 and the interaction between N protein and p53. In the nucleus, the binding of N protein to p53 maintained consistently high-level expression of p53, which activated the p53-DREAM pathway. The key domain of the N protein interacting with p53 was revealed to be S171RGNSQNRGNNQGRGASQNRGGNN194 (NS171-N194), in which G183RG185 are core residues. NS171-N194 and G183RG185 were essential for N-induced S-phase arrest. Moreover, small molecular drugs targeting the NS171-N194 domain of the PEDV N protein were screened through molecular docking. Hyperoside could antagonize N protein-induced S-phase arrest by interfering with interaction between N protein and p53 and inhibit viral replication (P < 0.05). The above-described experiments were also validated in porcine intestinal cells, and data were in line with results in Vero E6 cells. Therefore, these results reveal the PEDV N protein interacts with p53 to activate the p53-DREAM pathway, and subsequently induces S-phase arrest to create a favorable environment for virus replication. These findings provide new insight into the PEDV-host interaction and the design of novel antiviral strategies against PEDV. IMPORTANCE Many viruses subvert the host cell cycle to create a cellular environment that promotes viral growth. PEDV, an emerging and reemerging coronavirus, has led to substantial economic loss in the global swine industry. Our study is the first to demonstrate that PEDV N-induced cell cycle arrest during the S-phase promotes viral replication. We identified a novel mechanism of PEDV N-induced S-phase arrest, where the binding of PEDV N protein to p53 maintains consistently high levels of p53 expression in the nucleus to mediate S-phase arrest by activating the p53-DREAM pathway. Furthermore, a small molecular compound, hyperoside, targeted the PEDV N protein, interfering with the interaction between the N protein and p53 and, importantly, inhibited PEDV replication by antagonizing cell cycle arrest. This study reveals a new mechanism of PEDV-host interaction and also provides a novel antiviral strategy for PEDV. These data provide a foundation for further research into coronavirus-host interactions.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus Nucleocapsid Proteins/chemistry , Host-Pathogen Interactions/drug effects , Porcine epidemic diarrhea virus/drug effects , Quercetin/analogs & derivatives , Tumor Suppressor Protein p53/chemistry , Amino Acid Sequence , Animals , Antiviral Agents/chemistry , Binding Sites , Cell Line , Chlorocebus aethiops , Coronavirus Infections/drug therapy , Coronavirus Infections/genetics , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Coronavirus Nucleocapsid Proteins/antagonists & inhibitors , Coronavirus Nucleocapsid Proteins/genetics , Coronavirus Nucleocapsid Proteins/metabolism , Epithelial Cells/drug effects , Epithelial Cells/virology , Gene Expression Regulation , High-Throughput Screening Assays , Host-Pathogen Interactions/genetics , Molecular Docking Simulation , Nuclear Localization Signals , Porcine epidemic diarrhea virus/genetics , Porcine epidemic diarrhea virus/metabolism , Protein Binding , Protein Conformation , Protein Interaction Domains and Motifs , Quercetin/chemistry , Quercetin/pharmacology , S Phase Cell Cycle Checkpoints/drug effects , S Phase Cell Cycle Checkpoints/genetics , Signal Transduction , Swine , Swine Diseases/drug therapy , Swine Diseases/genetics , Swine Diseases/metabolism , Swine Diseases/virology , Tumor Suppressor Protein p53/antagonists & inhibitors , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Vero Cells , Virus Replication/drug effects
3.
Int J Mol Sci ; 22(17)2021 Aug 30.
Article in English | MEDLINE | ID: covidwho-1379978

ABSTRACT

The SARS-CoV-2 main protease (Mpro) is one of the molecular targets for drug design. Effective vaccines have been identified as a long-term solution but the rate at which they are being administered is slow in several countries, and mutations of SARS-CoV-2 could render them less effective. Moreover, remdesivir seems to work only with some types of COVID-19 patients. Hence, the continuous investigation of new treatments for this disease is pivotal. This study investigated the inhibitory role of natural products against SARS-CoV-2 Mpro as repurposable agents in the treatment of coronavirus disease 2019 (COVID-19). Through in silico approach, selected flavonoids were docked into the active site of Mpro. The free energies of the ligands complexed with Mpro were computationally estimated using the molecular mechanics-generalized Born surface area (MM/GBSA) method. In addition, the inhibition process of SARS-CoV-2 Mpro with these ligands was simulated at 100 ns in order to uncover the dynamic behavior and complex stability. The docking results showed that the selected flavonoids exhibited good poses in the binding domain of Mpro. The amino acid residues involved in the binding of the selected ligands correlated well with the residues involved with the mechanism-based inhibitor (N3) and the docking score of Quercetin-3-O-Neohesperidoside (-16.8 Kcal/mol) ranked efficiently with this inhibitor (-16.5 Kcal/mol). In addition, single-structure MM/GBSA rescoring method showed that Quercetin-3-O-Neohesperidoside (-87.60 Kcal/mol) is more energetically favored than N3 (-80.88 Kcal/mol) and other ligands (Myricetin 3-Rutinoside (-87.50 Kcal/mol), Quercetin 3-Rhamnoside (-80.17 Kcal/mol), Rutin (-58.98 Kcal/mol), and Myricitrin (-49.22 Kcal/mol). The molecular dynamics simulation (MDs) pinpointed the stability of these complexes over the course of 100 ns with reduced RMSD and RMSF. Based on the docking results and energy calculation, together with the RMSD of 1.98 ± 0.19 Å and RMSF of 1.00 ± 0.51 Å, Quercetin-3-O-Neohesperidoside is a better inhibitor of Mpro compared to N3 and other selected ligands and can be repurposed as a drug candidate for the treatment of COVID-19. In addition, this study demonstrated that in silico docking, free energy calculations, and MDs, respectively, are applicable to estimating the interaction, energetics, and dynamic behavior of molecular targets by natural products and can be used to direct the development of novel target function modulators.


Subject(s)
Biological Products/metabolism , SARS-CoV-2/enzymology , Viral Matrix Proteins/metabolism , Binding Sites , Biological Products/chemistry , Biological Products/therapeutic use , COVID-19/drug therapy , COVID-19/pathology , COVID-19/virology , Catalytic Domain , Drug Design , Humans , Ligands , Molecular Docking Simulation , Molecular Dynamics Simulation , Protease Inhibitors/chemistry , Protease Inhibitors/metabolism , Protease Inhibitors/therapeutic use , Quercetin/analogs & derivatives , Quercetin/chemistry , Quercetin/metabolism , Quercetin/therapeutic use , SARS-CoV-2/isolation & purification , Viral Matrix Proteins/chemistry
4.
Bioorg Med Chem ; 45: 116329, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1372898

ABSTRACT

Agrimonia pilosa (AP), Galla rhois (RG), and their mixture (APRG64) strongly inhibited SARS-CoV-2 by interfering with multiple steps of the viral life cycle including viral entry and replication. Furthermore, among 12 components identified in APRG64, three displayed strong antiviral activity, ursolic acid (1), quercetin (7), and 1,2,3,4,6-penta-O-galloyl-ß-d-glucose (12). Molecular docking analysis showed these components to bind potently to the spike receptor-binding-domain (RBD) of the SARS-CoV-2 and its variant B.1.1.7. Taken together, these findings indicate APRG64 as a potent drug candidate to treat SARS-CoV-2 and its variants.


Subject(s)
Agrimonia/chemistry , Antiviral Agents/chemistry , Biological Products/chemistry , COVID-19/drug therapy , Plant Extracts/chemistry , SARS-CoV-2/drug effects , Amino Acid Sequence , Antiviral Agents/pharmacology , Biological Products/pharmacology , Drug Discovery , Humans , Hydrolyzable Tannins/chemistry , Molecular Docking Simulation , Plant Extracts/pharmacology , Protein Binding , Quercetin/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Triterpenes/chemistry , Virus Internalization/drug effects
5.
Int J Mol Sci ; 22(13)2021 Jun 30.
Article in English | MEDLINE | ID: covidwho-1288904

ABSTRACT

The development of new antiviral drugs against SARS-CoV-2 is a valuable long-term strategy to protect the global population from the COVID-19 pandemic complementary to the vaccination. Considering this, the viral main protease (Mpro) is among the most promising molecular targets in light of its importance during the viral replication cycle. The natural flavonoid quercetin 1 has been recently reported to be a potent Mpro inhibitor in vitro, and we explored the effect produced by the introduction of organoselenium functionalities in this scaffold. In particular, we report here a new synthetic method to prepare previously inaccessible C-8 seleno-quercetin derivatives. By screening a small library of flavonols and flavone derivatives, we observed that some compounds inhibit the protease activity in vitro. For the first time, we demonstrate that quercetin (1) and 8-(p-tolylselenyl)quercetin (2d) block SARS-CoV-2 replication in infected cells at non-toxic concentrations, with an IC50 of 192 µM and 8 µM, respectively. Based on docking experiments driven by experimental evidence, we propose a non-covalent mechanism for Mpro inhibition in which a hydrogen bond between the selenium atom and Gln189 residue in the catalytic pocket could explain the higher Mpro activity of 2d and, as a result, its better antiviral profile.


Subject(s)
Antiviral Agents/chemistry , Quercetin/chemistry , SARS-CoV-2/metabolism , Selenium/chemistry , Viral Matrix Proteins/antagonists & inhibitors , Animals , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Binding Sites , COVID-19/pathology , COVID-19/virology , Catalytic Domain , Chlorocebus aethiops , Humans , Hydrogen Bonding , Molecular Docking Simulation , Protease Inhibitors/chemistry , Protease Inhibitors/metabolism , Protease Inhibitors/pharmacology , Quercetin/metabolism , Quercetin/pharmacology , SARS-CoV-2/isolation & purification , Selenium/metabolism , Vero Cells , Viral Matrix Proteins/metabolism , Virus Replication/drug effects
6.
Brief Bioinform ; 22(6)2021 11 05.
Article in English | MEDLINE | ID: covidwho-1246687

ABSTRACT

BACKGROUND: The clinical consequences of SARS-CoV-2 and DENGUE virus co-infection are not promising. However, their treatment options are currently unavailable. Current studies have shown that quercetin is both resistant to COVID-19 and DENGUE; this study aimed to evaluate the possible functional roles and underlying mechanisms of action of quercetin as a potential molecular candidate against COVID-19 and DENGUE co-infection. METHODS: We used a series of bioinformatics analyses to understand and characterize the biological functions, pharmacological targets and therapeutic mechanisms of quercetin in COVID-19 and DENGUE co-infection. RESULTS: We revealed the clinical characteristics of COVID-19 and DENGUE, including pathological mechanisms, key inflammatory pathways and possible methods of intervention, 60 overlapping targets related to the co-infection and the drug were identified, the protein-protein interaction (PPI) was constructed and TNFα, CCL-2 and CXCL8 could become potential drug targets. Furthermore, we disclosed the signaling pathways, biological functions and upstream pathway activity of quercetin in COVID-19 and DENGUE. The analysis indicated that quercetin could inhibit cytokines release, alleviate excessive immune responses and eliminate inflammation, through NF-κB, IL-17 and Toll-like receptor signaling pathway. CONCLUSIONS: This study is the first to reveal quercetin as a pharmacological drug for COVID-19 and DENGUE co-infection. COVID-19 and DENGUE co-infection remain a potential threat to the world's public health system. Therefore, we need innovative thinking to provide admissible evidence for quercetin as a potential molecule drug for the treatment of COVID-19 and DENGUE, but the findings have not been verified in actual patients, so further clinical drug trials are needed.


Subject(s)
COVID-19/drug therapy , Dengue Virus/chemistry , Dengue/drug therapy , Quercetin/chemistry , SARS-CoV-2/chemistry , COVID-19/complications , COVID-19/genetics , COVID-19/virology , Chemokine CCL2/chemistry , Chemokine CCL2/drug effects , Chemokine CCL2/genetics , Coinfection/drug therapy , Coinfection/genetics , Coinfection/virology , Dengue/complications , Dengue/genetics , Dengue/virology , Dengue Virus/drug effects , Humans , Interleukin-17/genetics , Interleukin-8/chemistry , Interleukin-8/drug effects , Interleukin-8/genetics , NF-kappa B/drug effects , NF-kappa B/genetics , Protein Interaction Maps/drug effects , Quercetin/therapeutic use , SARS-CoV-2/drug effects , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/chemistry , Tumor Necrosis Factor-alpha/drug effects , Tumor Necrosis Factor-alpha/genetics
7.
Drug Dev Res ; 82(8): 1124-1130, 2021 12.
Article in English | MEDLINE | ID: covidwho-1178984

ABSTRACT

Coronavirus Disease 2019 (COVID-19) cases and deaths are still rising worldwide, there is currently no effective treatment for severe inflammation and acute lung injury caused by new coronavirus (SARS-COV-2) infection. Therapies to prevent or treat COVID-19, including antiviral drug and several vaccines, are still being development. Human angiotensin-converting enzyme 2 (ACE2), expressing in lung, has been confirmed to be a receptor for SARS-COV-2 infection, interventions for attachment of spike protein of SARS-CoV-2 to ACE2 may be a potential approach to prevent viral infections and it is considered as a potential target for drug development. In this study, we observed that seabuckthorn and its flavonoid compounds quercetin and isorhamnetin were shown strong retention to ACE2 overexpression HEK293 (ACE2h ) cells by CMC analysis. Based on drug receptor interaction analysis and viral entry studies in vitro, we evaluated the interaction of two flavonoid compounds and ACE2 as well as the inhibitory effect of the two compounds on viral entry. Surface plasmon resonance assay proved the effect that isorhamnetin bound to the ACE2, and its affinity (KD value) was at the micromolar level, that was, 2.51 ± 0.68 µM. Viral entry studies in vitro indicated that isorhamnetin inhibited SARS-CoV-2 spike pseudotyped virus entering ACE2h cells. Based on promising in vitro results, we proposed isorhamnetin to be a potential therapeutic candidate compound against COVID-19.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Quercetin/analogs & derivatives , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2/chemistry , Antiviral Agents , HEK293 Cells , Hippophae/chemistry , Humans , Molecular Conformation , Molecular Docking Simulation , Protein Binding/drug effects , Quercetin/chemistry , Quercetin/pharmacology , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/chemistry , Virus Internalization/drug effects
8.
Molecules ; 25(22)2020 Nov 11.
Article in English | MEDLINE | ID: covidwho-917015

ABSTRACT

Flavonoids are phytochemical compounds present in many plants, fruits, vegetables, and leaves, with potential applications in medicinal chemistry. Flavonoids possess a number of medicinal benefits, including anticancer, antioxidant, anti-inflammatory, and antiviral properties. They also have neuroprotective and cardio-protective effects. These biological activities depend upon the type of flavonoid, its (possible) mode of action, and its bioavailability. These cost-effective medicinal components have significant biological activities, and their effectiveness has been proved for a variety of diseases. The most recent work is focused on their isolation, synthesis of their analogs, and their effects on human health using a variety of techniques and animal models. Thousands of flavonoids have been successfully isolated, and this number increases steadily. We have therefore made an effort to summarize the isolated flavonoids with useful activities in order to gain a better understanding of their effects on human health.


Subject(s)
Flavonoids/chemistry , Flavonoids/pharmacology , Alzheimer Disease/drug therapy , Alzheimer Disease/prevention & control , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Antimalarials/chemistry , Antimalarials/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Cardiovascular System/drug effects , Flavonoids/economics , Humans , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Mice , Nervous System/drug effects , Neurons/drug effects , Neuroprotective Agents/chemistry , Neuroprotective Agents/pharmacology , Plant Extracts/pharmacology , Plant Leaves/chemistry , Plants/chemistry , Polyphenols/chemistry , Polyphenols/pharmacology , Quercetin/chemistry , Quercetin/pharmacology , Rats , Rats, Sprague-Dawley , Rats, Wistar , Stroke/drug therapy , Stroke/prevention & control
9.
Mar Drugs ; 19(2)2021 Jan 27.
Article in English | MEDLINE | ID: covidwho-1050622

ABSTRACT

Inorganic polyphosphate (polyP) is a widely distributed polymer found from bacteria to animals, including marine species. This polymer exhibits morphogenetic as well as antiviral activity and releases metabolic energy after enzymatic hydrolysis also in human cells. In the pathogenesis of the coronavirus disease 2019 (COVID-19), the platelets are at the frontline of this syndrome. Platelets release a set of molecules, among them polyP. In addition, the production of airway mucus, the first line of body defense, is impaired in those patients. Therefore, in this study, amorphous nanoparticles of the magnesium salt of polyP (Mg-polyP-NP), matching the size of the coronavirus SARS-CoV-2, were prepared and loaded with the secondary plant metabolite quercetin or with dexamethasone to study their effects on the respiratory epithelium using human alveolar basal epithelial A549 cells as a model. The results revealed that both compounds embedded into the polyP nanoparticles significantly increased the steady-state-expression of the MUC5AC gene. This mucin species is the major mucus glycoprotein present in the secreted gel-forming mucus. The level of gene expression caused by quercetin or with dexamethasone, if caged into polyP NP, is significantly higher compared to the individual drugs alone. Both quercetin and dexamethasone did not impair the growth-supporting effect of polyP on A549 cells even at concentrations of quercetin which are cytotoxic for the cells. A possible mechanism of the effects of the two drugs together with polyP on mucin expression is proposed based on the scavenging of free oxygen species and the generation of ADP/ATP from the polyP, which is needed for the organization of the protective mucin-based mucus layer.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Antioxidants/pharmacology , Dexamethasone/pharmacology , Mucin 5AC/biosynthesis , Mucin 5AC/drug effects , Quercetin/pharmacology , A549 Cells , Anti-Inflammatory Agents/chemistry , Antioxidants/chemistry , COVID-19 , Dexamethasone/chemistry , Free Radical Scavengers/pharmacology , Gene Expression Regulation/drug effects , Humans , Magnesium/chemistry , Mucin 5AC/genetics , Mucins/biosynthesis , Mucins/chemistry , Nanoparticles , Particle Size , Plants/chemistry , Polyphosphates/chemistry , Quercetin/chemistry , Reactive Oxygen Species
10.
J Agric Food Chem ; 68(47): 13982-13989, 2020 Nov 25.
Article in English | MEDLINE | ID: covidwho-920571

ABSTRACT

Angiotensin-converting enzyme 2 (ACE2) is a host receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Inhibiting the interaction between the envelope spike glycoproteins (S-proteins) of SARS-CoV-2 and ACE2 is a potential antiviral therapeutic approach, but little is known about how dietary compounds interact with ACE2. The objective of this study was to determine if flavonoids and other polyphenols with B-ring 3',4'-hydroxylation inhibit recombinant human (rh)ACE2 activity. rhACE2 activity was assessed with the fluorogenic substrate Mca-APK(Dnp). Polyphenols reduced rhACE2 activity by 15-66% at 10 µM. Rutin, quercetin-3-O-glucoside, tamarixetin, and 3,4-dihydroxyphenylacetic acid inhibited rhACE2 activity by 42-48%. Quercetin was the most potent rhACE2 inhibitor among the polyphenols tested, with an IC50 of 4.48 µM. Thus, quercetin, its metabolites, and polyphenols with 3',4'-hydroxylation inhibited rhACE2 activity at physiologically relevant concentrations in vitro.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/chemistry , Peptidyl-Dipeptidase A/chemistry , Polyphenols/chemistry , Quercetin/chemistry , Angiotensin-Converting Enzyme 2 , Enzyme Assays , Humans , Kinetics , Recombinant Proteins/chemistry , Temperature
11.
Int J Biol Macromol ; 164: 1693-1703, 2020 Dec 01.
Article in English | MEDLINE | ID: covidwho-704182

ABSTRACT

The global health emergency generated by coronavirus disease 2019 (COVID-19) has prompted the search for preventive and therapeutic treatments for its pathogen, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There are many potential targets for drug discovery and development to tackle this disease. One of these targets is the main protease, Mpro or 3CLpro, which is highly conserved among coronaviruses. 3CLpro is an essential player in the viral replication cycle, processing the large viral polyproteins and rendering the individual proteins functional. We report a biophysical characterization of the structural stability and the catalytic activity of 3CLpro from SARS-CoV-2, from which a suitable experimental in vitro molecular screening procedure has been designed. By screening of a small chemical library consisting of about 150 compounds, the natural product quercetin was identified as reasonably potent inhibitor of SARS-CoV-2 3CLpro (Ki ~ 7 µM). Quercetin could be shown to interact with 3CLpro using biophysical techniques and bind to the active site in molecular simulations. Quercetin, with well-known pharmacokinetic and ADMET properties, can be considered as a good candidate for further optimization and development, or repositioned for COVID-19 therapeutic treatment.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/enzymology , Cysteine Endopeptidases/chemistry , Protease Inhibitors/pharmacology , Quercetin/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/chemistry , Antiviral Agents/chemistry , Betacoronavirus/chemistry , Betacoronavirus/drug effects , COVID-19 , Catalytic Domain/drug effects , Coronavirus 3C Proteases , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cysteine Endopeptidases/metabolism , Drug Discovery , Humans , Molecular Docking Simulation , Pandemics , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Protease Inhibitors/chemistry , Protein Conformation/drug effects , Protein Unfolding , Quercetin/chemistry , SARS-CoV-2 , Viral Nonstructural Proteins/metabolism
12.
Front Immunol ; 11: 1451, 2020.
Article in English | MEDLINE | ID: covidwho-637661

ABSTRACT

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) represents an emergent global threat which is straining worldwide healthcare capacity. As of May 27th, the disease caused by SARS-CoV-2 (COVID-19) has resulted in more than 340,000 deaths worldwide, with 100,000 deaths in the US alone. It is imperative to study and develop pharmacological treatments suitable for the prevention and treatment of COVID-19. Ascorbic acid is a crucial vitamin necessary for the correct functioning of the immune system. It plays a role in stress response and has shown promising results when administered to the critically ill. Quercetin is a well-known flavonoid whose antiviral properties have been investigated in numerous studies. There is evidence that vitamin C and quercetin co-administration exerts a synergistic antiviral action due to overlapping antiviral and immunomodulatory properties and the capacity of ascorbate to recycle quercetin, increasing its efficacy. Safe, cheap interventions which have a sound biological rationale should be prioritized for experimental use in the current context of a global health pandemic. We present the current evidence for the use of vitamin C and quercetin both for prophylaxis in high-risk populations and for the treatment of COVID-19 patients as an adjunct to promising pharmacological agents such as Remdesivir or convalescent plasma.


Subject(s)
Antiviral Agents/therapeutic use , Ascorbic Acid/therapeutic use , Betacoronavirus/physiology , Coronavirus Infections/prevention & control , Immunologic Factors/therapeutic use , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Pre-Exposure Prophylaxis/methods , Quercetin/therapeutic use , Animals , Antiviral Agents/adverse effects , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Betacoronavirus/drug effects , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Drug Synergism , Drug Therapy, Combination , Humans , Mice , Pneumonia, Viral/virology , Quercetin/adverse effects , Quercetin/chemistry , Quercetin/pharmacokinetics , SARS-CoV-2 , Virus Replication/drug effects
13.
Biochem Pharmacol ; 178: 114123, 2020 08.
Article in English | MEDLINE | ID: covidwho-614389

ABSTRACT

Commonly used drugs for treating many conditions are either natural products or derivatives. In silico modelling has identified several natural products including quercetin as potential highly effective disruptors of the initial infection process involving binding to the interface between the SARS-CoV-2 (Covid-19) Viral Spike Protein and the epithelial cell Angiotensin Converting Enzyme-2 (ACE2) protein. Here we argue that the oral route of administration of quercetin is unlikely to be effective in clinical trials owing to biotransformation during digestion, absorption and metabolism, but suggest that agents could be administered directly by alternative routes such as a nasal or throat spray.


Subject(s)
Betacoronavirus/drug effects , Biological Products/pharmacology , Peptidyl-Dipeptidase A/metabolism , Quercetin/pharmacology , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2 , Betacoronavirus/metabolism , Betacoronavirus/physiology , Biological Products/administration & dosage , Biological Products/chemistry , COVID-19 , Clinical Trials as Topic/methods , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Drug Evaluation, Preclinical/methods , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Epithelial Cells/virology , Host-Pathogen Interactions/drug effects , Humans , Molecular Structure , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Pneumonia, Viral/virology , Protein Binding/drug effects , Quercetin/administration & dosage , Quercetin/chemistry , SARS-CoV-2 , Virus Internalization/drug effects
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