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1.
Food Chem ; 351: 129324, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33647694

RESUMO

Conjugation between peptides and polyphenols could improve their bioactive and functional properties. The improvement effects of anchovy protein hydrolysates (APH) -polyphenol (catechin (CA), gallic acid (GA), tannic acid (TA)) conjugates were investigated. The content of protein and polyphenols and ratio of polyphenols/peptides in conjugates increased as the number of OH group increased with TA > CA > GA. Results showed that APH-CA and APH-GA exhibited the highest ORAC and ABTS+ scavenging capacity, respectively. Mass spectrometry analysis suggested the highest number of bioactive peptides were identified in APH-CA 5:1 (APH/polyphenols). The physical stability of fish oil emulsions during storage was significantly enhanced by TA 5:1 conjugate followed by CA 5:1 conjugate. The oxidative stability was remarkably elevated by APH-GA 10:1. This was due to the antioxidant capacity and the peptides adsorbed at the interfacial. This study demonstrated that APH-polyphenol conjugates could bring the possibility of utilizing peptides-polyphenols in the nutraceutical and functional food ingredient fields.


Assuntos
Antioxidantes/química , Óleos de Peixe/química , Proteínas de Peixes/química , Polifenóis/química , Animais , Catequina/química , Emulsões , Hidrólise , Oxirredução , Taninos/química
2.
Molecules ; 26(5)2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33652639

RESUMO

Hepatitis C is affecting millions of people around the globe annually, which leads to death in very high numbers. After many years of research, hepatitis C virus (HCV) remains a serious threat to the human population and needs proper management. The in silico approach in the drug discovery process is an efficient method in identifying inhibitors for various diseases. In our study, the interaction between Epigallocatechin-3-gallate, a component of green tea, and envelope glycoprotein E2 of HCV is evaluated. Epigallocatechin-3-gallate is the most promising polyphenol approved through cell culture analysis that can inhibit the entry of HCV. Therefore, various in silico techniques have been employed to find out other potential inhibitors that can behave as EGCG. Thus, the homology modelling of E2 protein was performed. The potential lead molecules were predicted using ligand-based as well as structure-based virtual screening methods. The compounds obtained were then screened through PyRx. The drugs obtained were ranked based on their binding affinities. Furthermore, the docking of the topmost drugs was performed by AutoDock Vina, while its 2D interactions were plotted in LigPlot+. The lead compound mms02387687 (2-[[5-[(4-ethylphenoxy) methyl]-4-prop-2-enyl-1,2,4-triazol-3-yl] sulfanyl]-N-[3(trifluoromethyl) phenyl] acetamide) was ranked on top, and we believe it can serve as a drug against HCV in the future, owing to experimental validation.


Assuntos
Catequina/análogos & derivados , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Proteínas do Envelope Viral/genética , Antivirais/química , Antivirais/farmacologia , Catequina/química , Catequina/farmacologia , Hepacivirus/genética , Hepacivirus/patogenicidade , Hepatite C/virologia , Humanos , Ligantes , Simulação de Acoplamento Molecular , Polifenóis/química , Polifenóis/farmacologia , Chá/química , Proteínas do Envelope Viral/antagonistas & inibidores , Internalização do Vírus/efeitos dos fármacos
3.
Molecules ; 26(5)2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668085

RESUMO

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged to be the greatest threat to humanity in the modern world and has claimed nearly 2.2 million lives worldwide. The United States alone accounts for more than one fourth of 100 million COVID-19 cases across the globe. Although vaccination against SARS-CoV-2 has begun, its efficacy in preventing a new or repeat COVID-19 infection in immunized individuals is yet to be determined. Calls for repurposing of existing, approved, drugs that target the inflammatory condition in COVID-19 are growing. Our initial gene ontology analysis predicts a similarity between SARS-CoV-2 induced inflammatory and immune dysregulation and the pathophysiology of rheumatoid arthritis. Interestingly, many of the drugs related to rheumatoid arthritis have been found to be lifesaving and contribute to lower COVID-19 morbidity. We also performed in silico investigation of binding of epigallocatechin gallate (EGCG), a well-known catechin, and other catechins on viral proteins and identified papain-like protease protein (PLPro) as a binding partner. Catechins bind to the S1 ubiquitin-binding site of PLPro, which might inhibit its protease function and abrogate SARS-CoV-2 inhibitory function on ubiquitin proteasome system and interferon stimulated gene system. In the realms of addressing inflammation and how to effectively target SARS-CoV-2 mediated respiratory distress syndrome, we review in this article the available knowledge on the strategic placement of EGCG in curbing inflammatory signals and how it may serve as a broad spectrum therapeutic in asymptomatic and symptomatic COVID-19 patients.


Assuntos
Antivirais , Catequina/análogos & derivados , Inibidores de Cisteína Proteinase , Chá/química , Antivirais/química , Antivirais/uso terapêutico , Sítios de Ligação , /epidemiologia , Catequina/química , Catequina/uso terapêutico , /química , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/uso terapêutico , Humanos
4.
Food Chem ; 350: 129222, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33607411

RESUMO

The reaction pathways were investigated by which a fungoid chitosan (CsG) may protect against photooxidative decay of model solutions and a sulphite-free white wine. Samples containing CsG were dark incubated for 2 days before exposure to fluorescent lighting for up to 21 days in the presence of wine like (+)-catechin and/or iron doses. In both systems CsG at winemaking doses significantly reduced the photoproduction of acetaldehyde and, to a better extent, glyoxylic acid, two key reactive aldehydes implicated in wine oxidative spoilage. After 21 days, CsG was two-fold more effective than sulphur dioxide in preventing glyoxylic acid formation and minimizing the browning of white wine. Among the antioxidant mechanisms involved in CsG protective effect, iron chelation, and hydrogen peroxide quenching were demonstrated. Besides, the previously unreported tartrate displacement from the [iron(III)-tartrate] complex was revealed as an additional inhibitory mechanism of CsG under photo-Fenton oxidation conditions.


Assuntos
Aldeídos/química , Quitosana/química , Processos Fotoquímicos , Vinho/análise , Antioxidantes/química , Catequina/química , Glioxilatos/química , Oxirredução , Dióxido de Enxofre/química , Tartaratos/química
5.
Food Chem ; 350: 129251, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33588282

RESUMO

The pea protein isolate-high methoxyl pectin-epigallocatechin gallate (PPI-HMP-EGCG) complex was used to stabilize Pickering emulsions (PEs) and high internal phase PEs (HIPPEs), and the effect of interfacial rheology on the microstructure, bulk rheology and stability of these emulsions was investigated. The PPI-HMP-EGCG complex with PPI to EGCG 30:1 exhibited partial wettability (81.6 ± 0.4°) and optimal viscoelasticity for the formation of stable interfacial layer. The microstructure demonstrated that the PPI-HMP-EGCG complex acted as an interfacial layer and surrounded the oil droplets, and continuous phases were mainly filled with excessive HMP, which enhanced emulsion stability. The formation of a firm gel-like network structure required a dense interfacial layer to provide the PEs (complex concentration of 0.1%) and HIPPEs (oil-phase up to 0.83) with ideal viscoelasticity and stability. The results provide the guidelines for the rational design of EGCG-loaded HIPPEs stabilized by water-soluble protein/polysaccharide complexes.


Assuntos
Catequina/análogos & derivados , Proteínas de Ervilha/química , Pectinas/química , Catequina/química , Emulsões , Reologia , Viscosidade , Água/química , Molhabilidade
6.
Sci Rep ; 11(1): 2043, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33479401

RESUMO

The recent outbreak of the coronavirus (SARS-CoV2) is an unprecedented threat to human health and society across the globe. In this context, development of suitable interventions is the need of the hour. The viral spike protein (S Protein) and the cognate host cell receptor ACE2 can be considered as effective and appropriate targets for interventions. It is evident from the present computational study, that catechin and curcumin, not only exhibit strong binding affinity to viral S Protein and host receptor ACE2 but also to their complex (receptor-binding domain (RBD) of the spike protein of SARS-CoV2 and ACE2; RBD/ACE2-complex). The binding affinity values of catechin and curcumin for the S protein, ACE2 and RBD/ACE2-complex are - 10.5 and - 7.9 kcal/mol; - 8.9 and - 7.8 kcal/mol; and - 9.1 and - 7.6 kcal/mol, respectively. Curcumin directly binds to the receptor binding domain (RBD) of viral S Protein. Molecular simulation study over a period of 100 ns further substantiates that such interaction within RBD site of S Protein occurs during 40-100 ns out of 100 ns simulation trajectory. Contrary to this, catechin binds with amino acid residues present near the RBD site of S Protein and causes fluctuation in the amino acid residues of the RBD and its near proximity. Both catechin and curcumin bind the interface of 'RBD/ACE2-complex' and intervene in causing fluctuation of the alpha helices and beta-strands of the protein complex. Protein-protein interaction studies in presence of curcumin or catechin also corroborate the above findings suggesting the efficacy of these two polyphenols in hindering the formation of S Protein-ACE2 complex. In conclusion, this computational study for the first time predicts the possibility of above two polyphenols for therapeutic strategy against SARS-CoV2.


Assuntos
/metabolismo , Catequina/metabolismo , Curcumina/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , /metabolismo , Catequina/química , Catequina/farmacologia , Membrana Celular/metabolismo , Biologia Computacional/métodos , Curcumina/química , Curcumina/farmacologia , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Domínios Proteicos , Glicoproteína da Espícula de Coronavírus/química
7.
Food Chem ; 338: 128048, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32950869

RESUMO

In this study, theaflavins were used to interact with bovine lactoferrin (bLF) to observe the effects of theaflavins on the structure and functionality of bLF. Spectral experiments verified that theaflavins were able to interact with bLF by a static quenching method. The circular dichroism experiment further showed that the combination of theaflavins would lead a certain change in the structure of bLF. By comparing the calculated data of the spectral experiment and the degree of structural change after bLF binding to theaflavins, the theaflavin-3, 3'-digallate (TFDG), which had the strongest effect on the structure of bLF, was selected to explore its influence on effects of bLF functionality. Conclusions were drawn from iron binding, enzyme-linked immunosorbent and in vitro simulated digestion experiments-the addition of TFDG had a certain effect on the functionality of bLF.


Assuntos
Biflavonoides/química , Catequina/química , Lactoferrina/química , Sequência de Aminoácidos , Animais , Antioxidantes/química , Biflavonoides/metabolismo , Sítios de Ligação , Catequina/metabolismo , Bovinos , Dicroísmo Circular , Imunoglobulina E/química , Imunoglobulina E/metabolismo , Ferro/química , Ferro/metabolismo , Lactoferrina/metabolismo , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica
8.
Food Chem ; 340: 127908, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889206

RESUMO

This study aims to evaluate the effects of in vitro digestion of rice and common bean blends on phenolics content and profile. Black and carioca beans were used as common bean sources. Blends consisted of 25:75, 50:50, and 75:25 polished rice:beans (w/w). Pure rice or pure beans were also analyzed. Phenolic compounds were determined in raw, cooked, and digested samples. The glucose release through in vitro digestion was slower as the proportion of black beans or carioca beans increased. Starch digestibility ranged between 41.1 in 100% carioca bean to 84.4% in 100% rice. Hydroxybenzoic acid, ferulic acid, p-coumaric acid, catechin, and epicatechin were the most abundant phenolics detected in the studied samples. Considering the content of phenolic compounds determined in the raw, cooked, and digested grains, only a small fraction was available for absorption in the gut, with amounts varying from 0.1 to 0.6 µg·g-1.


Assuntos
Oryza/química , Phaseolus/química , Fenóis/análise , Amido/química , Amido/farmacocinética , Catequina/análise , Catequina/química , Culinária , Digestão , Glucose/farmacocinética , Hidroxibenzoatos/análise , Hidroxibenzoatos/química , Fenóis/química , Amido/análise
9.
Food Chem ; 338: 128013, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33091995

RESUMO

Chitosan-procyanidin composite films (CS-PC films) with different mass ratios were prepared by solution casting method. Their structural, thermal, physical, and antioxidant properties, antibacterial activity and pH responsivity were determined. Compared with CS-control film, CS-PC films exhibited lower solubility and higher tensile strength. The antimicrobial properties against Escherichia coli and Aspergillus niger were improved by 20.0% and 30.4%, respectively. CS-PC films indicated good antioxidant activity through their DPPH and ABTS+ scavenging rates, which were 2.45 times higher than CS-control film. pH responsivity was represented by the outstanding changes in color, which were visible to the naked eye. Food packaging film with high antioxidant activity, bacteriostatic properties and pH responsivity was prepared by CS and PC. Compared with the initial properties of cheese, the characteristics of cheese packaged with CS-PC films were obviously better than those of the control groups.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Biflavonoides/química , Catequina/química , Queijo/análise , Quitosana/química , Embalagem de Alimentos/métodos , Proantocianidinas/química , Anti-Infecciosos/farmacologia , Aspergillus niger/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Concentração de Íons de Hidrogênio
10.
Food Chem ; 339: 128112, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152889

RESUMO

Green tea nanoparticles (gTNPs) are considered as the precursors of tea cream, while the role of gTNPs in the process of tea cream formation remains obscure. This study indicated that gTNPs could be coated with epigallocatechin gallate (EGCG)-caffeine (CAF) complexes to form a ternary aggregate participating in tea cream formation. First, the ζ-potentials of gTNPs and EGCG-CAF complexes were adjusted by charge screening. Then, gTNPs were introduced into EGCG + CAF mixture solutions under different ζ-potential conditions to examine their effect on turbidity, particle size and components of mixture solutions. Finally, isothermal titration calorimetry (ITC) was applied to investigate the influence of gTNPs on the thermal effects of the interaction between EGCG and CAF. Our results reveal that hydrophobic interaction exceeded electrostatic repulsion to dominate the interaction between gTNPs and EGCG-CAF complexes at the low ζ-potential condition, thus forming the gTNPs/EGCG/CAF ternary aggregate.


Assuntos
Cafeína/química , Catequina/análogos & derivados , Nanopartículas/química , Chá/química , Calorimetria , Catequina/química , Difusão Dinâmica da Luz , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Transmissão
11.
Food Chem ; 339: 128145, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152895

RESUMO

The solution turbidity and intrinsic fluorescence quenching increased after procyanidin was mixed with lactoferrin. The addition of procyanidin also caused a reduction in the surface hydrophobicity of the lactoferrin, suggesting procyanidin bound to non-polar patches on lactoferrin's surfaces. Moreover, the binding interaction caused an appreciable alteration in the structure of both the polyphenol and protein. Thermodynamic analysis indicated the interaction was spontaneous and mainly driven by entropy changes, suggesting that hydrophobic interactions dominated. A computational docking simulation provided insights into the location of the most-likely binding sites on the protein, as well as the nature of the interaction forces involved. In particular, both hydrophobic and hydrogen bonding were found to be important. The binding of the procyanidin to the lactoferrin enhanced its foaming properties. These results may lead to the development of a new class of natural functional ingredients that can be used in food products to improve their quality attributes.


Assuntos
Biflavonoides/química , Catequina/química , Lactoferrina/química , Proantocianidinas/química , Animais , Biflavonoides/metabolismo , Sítios de Ligação , Catequina/metabolismo , Bovinos , Fluorescência , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lactoferrina/metabolismo , Simulação de Acoplamento Molecular , Proantocianidinas/metabolismo , Espectrometria de Fluorescência , Termodinâmica
12.
Food Chem ; 335: 127647, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32739816

RESUMO

The inhibition mechanism of the texture deterioration of tilapia fillets after treatment with polyphenols during partial freezing for 49 days was studied. Carnosic acid (CA), procyanidin (PA), quercetin (QE), and resveratrol (RSV) treatments had significantly higher hardness values (over 230 g) than the control group (183 g) on day 49 (P < 0.05). Polyphenol treatments were effective in delaying the protein degradation, lipid oxidation and spoilage microbe growth. Moreover, the kinetic model showed that the predicted shelf life of tilapia fillets treated with PA (102 d) was extended by 25 d compared to the control group (77 d). It was the proposed possible mechanism that polyphenols comprehensively maintained the protein conformation (increased hydrogen bonds and decreased disulfide bonds) and retarded protein denaturation and degradation, protecting the texture of the fillets. Therefore, polyphenols can be used to maintain texture and extend the shelf life of tilapia fillets during partial freezing.


Assuntos
Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Carne/análise , Polifenóis/análise , Polifenóis/farmacologia , Animais , Biflavonoides/química , Catequina/química , Proteínas de Peixes/química , Conservação de Alimentos/instrumentação , Congelamento , Oxirredução/efeitos dos fármacos , Proantocianidinas/química , Desnaturação Proteica/efeitos dos fármacos , Tilápia
13.
Food Chem ; 337: 127639, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32799157

RESUMO

A series of incubation systems of pure (-)-Epigallocatechin gallate (EGCG), ascorbic acid (AA) and dehydroascorbic acid (DHAA) at 80 °C were performed to investigated the effect and mechanism of AA on the stability of EGCG. Results shows the dual function of AA, protect action at low concentration and promoting degradation at high concentration, and the critical concentration is about 10 mmol/L. The protective properties of AA due to the reversible reaction from AA to DHAA inhibiting oxidation pathway of EGCG to EGCG quinone or other activated intermediates, and both AA and DHAA can inhibit the hydrolysis of EGCG. The properties of promoting degradation is mainly due to the fact that DHAA, the oxidation product of AA, can react with EGCG to generate some ascorbyl adducts of EGCG. This result is helpful to control the stability of catechins and further clarify the complex interaction on healthy between EGCG and AA.


Assuntos
Ácido Ascórbico/química , Catequina/análogos & derivados , Ácido Desidroascórbico/química , Chá/química , Catequina/química , Hidrólise , Oxirredução , Temperatura
14.
Food Chem ; 340: 127817, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889199

RESUMO

Impact of malondialdehyde (MDA) and (-)-Epigallocatechin-3-gallate (EGCG) on gelling properties of myofibrillar proteins (MPs) was investigated. Addition of 6 mM MDA enhanced molecular interactions of proteins, thus the strength and elastic modulus (G') of gel were improved. EGCG addition aggravated gel quality deterioration due to further modification of MPs induced by EGCG. Addition of 12 mM MDA jeopardized gel quality according to the increasing of strength and G', but the decreasing of water-holding capacity (WHC), and the collapse of microstructure. Nevertheless, EGCG reacted with MDA forming EGCG-MDA adducts, hence improved gel quality, which was supported by the decreasing of strength, but the increasing of WHC, and the repaired microstructure of gel at 12 mM MDA. Addition of 24 mM MDA severely jeopardized gel quality, which became even worse due to EGCG addition. This work is helpful to understand the impact of MDA and polyphenols on the gel-forming capacity of MPs.


Assuntos
Catequina/análogos & derivados , Géis/química , Malondialdeído/química , Proteínas de Carne/química , Animais , Catequina/química , Módulo de Elasticidade , Músculo Esquelético/química , Miofibrilas/química , Reologia , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos , Água/química
15.
Food Chem ; 340: 127845, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889218

RESUMO

Astringency is an important quality attribute of green tea infusion, and (-)-Epigallocatechin gallate (EGCG) is the main contributor to astringency. Turbidity was used to predict the intensity of astringency for EGCG. The interactions between the selected proteins and EGCG, and the impacts of temperature, pH, protein structure, and EGCG concentration were studied. Mucin was selected as the protein in study for the prediction of EGCG astringency intensity. A predictive model (R2 = 0.994) was developed based on the relationship between the astringency of EGCG and the turbidity of EGCG/mucin mixtures at pH 5.0 and 37 °C. The fluorescence quenching analyses showed the interactions between EGCG and the selected proteins, which induced the reversible protein molecule conformational changes. The interactions were considered as the main reason that causes the astringency of tea infusions. The results provided a biochemical approach to explore the sensory qualities of green tea.


Assuntos
Catequina/análogos & derivados , Proteínas e Peptídeos Salivares/química , Chá/química , Adulto , Catequina/química , Feminino , Fluorescência , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Mucinas/química , Conformação Proteica , Espectrometria de Fluorescência , Paladar , Temperatura
16.
Food Chem ; 340: 127830, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32919355

RESUMO

Procyanidins from coffee pulp are responsible from the limited valorization of this by-product. Information about procyanidin structure is still scarce and imprecise. The aim of this work was to study the native and oxidized procyanidins from coffee pulp with respect to composition and structure. An aqueous acetone extract from coffee pulp was purified using Sephadex LH-20. Butanolysis, phloroglucinolysis and thioglycolysis coupled to HLPC-ESI-MS were applied for the characterization of the native and oxidized procyanidins. The purification allowed to recovery three fractions (aqueous, ethanolic and acetonic) and only acetone fraction showed a high concentration of procyanidins (98%, w/w). HPLC-ESI-MS of procyanidins-rich fraction without any reaction resulted in a UV-Vis chromatogram unresolved typical of the presence of procyanidins. The extracted ion chromatogram and MS2 analysis revealed the presence from dimers to pentamers of native procyanidins. Interestingly, by first time an A-type trimeric procyanidin (m/z of 863) was observed in coffee pulp. In our study, (-)-epicatechin was the constitutive unit of procyanidins with an aDP of 6.8 (oligomeric native procyanidins) according to the phloroglucinolysis assay. Two oxidation markers useful to characterization of oxidized procyanidins were observed in the procyanidins-rich fraction after thioglycolysis, a dimer A2-ext and a molecule that corresponds to a linkage between an extension and a terminal unit. Coffee pulp procyanidins were presented with only a minor class of oxidized procyanidins. As far as we know, this is the first study about characterization of the oxidized procyanidins from coffee pulp.


Assuntos
Biflavonoides/análise , Biflavonoides/química , Catequina/análise , Catequina/química , Coffea/química , Proantocianidinas/análise , Proantocianidinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Cromatografia Líquida de Alta Pressão/métodos , Café/química , Glicólise , Oxirredução
17.
J Agric Food Chem ; 68(52): 15409-15417, 2020 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-33337882

RESUMO

Plant defense inducers (PDIs) are booming and attractive protection agents designed to immunostimulate the plant to reduce subsequent pathogen colonization. The structure-PDI activity relationships of four flavan-3-ols: Epicatechin (EC), Epigallocatechin (EGC), Epicatechin gallate (ECG), Epigallocatechin gallate (EGCG) and Gallotannic acid (GTA) were investigated in both whole plant and suspension cell systems. ECG, EGCG, and GTA displayed elicitor activities. Their infiltration into tobacco leaves induced hypersensitive reaction-like lesions with topical scopoletin and PR-target transcript accumulations. On the contrary, EC and EGC infiltrations fail to trigger the biochemical changes in tobacco tissues. The tobacco BY-2 cells challenged with ECG, EGCG, or GTA led to alkalinization of the BY-2 extracellular medium while EC and EGC did not trigger any pH variation. This work provides evidence that the esterified gallate pattern is as an essential flavonoid entity to induce plant defense reactions in tobacco. The phytoprotective properties of the esterified gallate-free EC and the esterified gallate-rich GTA were evaluated on the tobacco/Phytophthora parasitica var. nicotianae (Ppn) pathosystem. Tobacco treatment with EC did not induce significant protection against Ppn compared to GTA which shows antimicrobial properties on Ppn and decreases the infection on GTA-infiltrated and -sprayed wild-type leaves. GTA protection was impaired in the transgenic NahG tobacco plants, suggesting that protection was mediated by salicylic acid.


Assuntos
Flavonoides/química , Flavonoides/farmacologia , Doenças das Plantas/imunologia , Tabaco/efeitos dos fármacos , Catequina/análogos & derivados , Catequina/química , Catequina/farmacologia , Estrutura Molecular , Phytophthora/fisiologia , Doenças das Plantas/microbiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Tabaco/imunologia , Tabaco/microbiologia
18.
Int J Nanomedicine ; 15: 4969-4990, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764930

RESUMO

Background: Polyphenols possess antioxidant, anti-inflammatory and antimicrobial properties and have been used in the treatment of skin wounds and burns. We previously showed that tannic acid-modified AgNPs sized >26 nm promote wound healing, while tannic acid-modified AgNPs sized 13 nm can elicit strong local inflammatory response. In this study, we tested bimetallic Au@AgNPs sized 30 nm modified with selected flavonoid and non-flavonoid compounds for wound healing applications. Methods: Bimetallic Au@AgNPs were obtained by growing an Ag layer on AuNPs and further modified with selected polyphenols. After toxicity tests and in vitro scratch assay in HaCaT cells, modified lymph node assay as well as the mouse splint wound model were further used to access the wound healing potential of selected non-toxic modifications. Results: Tannic acid, gallic acid, polydatin, resveratrol, catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate and procyanidin B2 used to modify Au@AgNPs exhibited good toxicological profiles in HaCaT cells. Au@AgNPs modified with 15 µM tannic acid, 200 µM resveratrol, 200 µM epicatechin gallate, 1000 µM gallic acid and 200 µM procyanidin B2 induced wound healing in vivo and did not lead to the local irritation or inflammation. Tannic acid-modified Au@AgNPs induced epithelial-to-mesenchymal transition (EMT) - like re-epithelialization, while other polyphenol modifications of Au@AgNPs acted through proliferation and wound closure. Conclusion: Bimetallic Au@AgNPs can be used as a basis for modification with selected polyphenols for topical uses. In addition, we have demonstrated that particular polyphenols used to modify bimetallic nanoparticles may show different effects upon different stages of wound healing.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Polifenóis/química , Polifenóis/farmacologia , Prata/química , Cicatrização/efeitos dos fármacos , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Biflavonoides/química , Catequina/análogos & derivados , Catequina/química , Camundongos , Proantocianidinas/química , Taninos/química
19.
Arch Biochem Biophys ; 692: 108511, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32710883

RESUMO

(-)-Epigallocatechin-3-gallate (EGCG), the most abundant catechin component in green tea, has been reported to attenuate age-associated insulin resistance, lipogenesis and loss of muscle mass through restoring Akt activity in skeletal muscle in our previous and present studies. Accumulated data has suggested that polyphenols regulate signaling pathways involved in aging process such as inflammation and oxidative stress via modulation of miRNA expression. Here we found that miRNA-486-5p was significantly decreased in both aged senescence accelerated mouse-prone 8 (SAMP8) mice and late passage C2C12 cells. Thus, we further investigated the regulatory effect of EGCG on miRNA-486-5p expression in age-regulated muscle loss. SAMP8 mice were fed with chow diet containing without or with 0.32% EGCG from aged 32 weeks for 8 weeks. Early passage (<12 passages) and late passage (>30 passages) of C2C12 cells were treated without or with EGCG at concentrations of 50 µM for 24h. Our data showed that EGCG supplementation increased miRNA-486-5p expression in both aged SAMP8 mice and late passage C2C12 cells. EGCG stimulated AKT phosphorylation and inhibited FoxO1a-mediated MuRF1 and Atrogin-1 transcription via up-regulating the expression of miR-486 in skeletal muscle of 40-wk-old SAMP8 mice as well as late passage C2C12 cells. In addition, myostatin expression was increased in late passage C2C12 cells and anti-myostatin treatment upregulated the expression of miR-486-5p. Our results identify a unique mechanism of a dietary constituent of green tea and suggest that use of EGCG or compounds derived from it attenuates age-associated muscle loss via myostatin/miRNAs/ubiquitin-proteasome signaling.


Assuntos
Envelhecimento/metabolismo , Catequina/análogos & derivados , Regulação da Expressão Gênica/efeitos dos fármacos , MicroRNAs/metabolismo , Proteínas Musculares/biossíntese , Atrofia Muscular/metabolismo , Miostatina/biossíntese , Envelhecimento/efeitos dos fármacos , Envelhecimento/genética , Envelhecimento/patologia , Animais , Catequina/química , Catequina/farmacologia , Linhagem Celular , Camundongos , Camundongos Transgênicos , MicroRNAs/genética , Proteínas Musculares/genética , Atrofia Muscular/genética , Atrofia Muscular/patologia , Miostatina/genética , Chá/química
20.
Food Chem ; 332: 127467, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663755

RESUMO

The mood pyramid of cocoa, which was previously proposed as a new concept, consists of four levels (flavan-3-ols, methylxanthines, minor compounds and orosensory properties). Roasting is a crucial process for flavor development in cocoa but is likely to have a negative impact on the phytochemicals. We investigated the effect of roasting time (10-50 min) and temperature (110-160 °C) on the potential mood-enhancing compounds corresponding to the distinct mood pyramid levels. Phytochemicals were analyzed using UPLC-HRMS, while the flavor was mapped via aroma (HS-SPME-GC-MS) and generic descriptive analysis (trained panel). Results revealed that roasting at 130 °C for 30 min did not significantly affect the levels of epicatechin, procyanidin B2 and theobromine, while salsolinol significantly increased. Moreover, bitterness and astringency were reduced and the desired cocoa flavor was developed. Thus, through selection of appropriate roasting time and temperature conditions phytochemicals of interest could be retained without comprising the flavor.


Assuntos
Cacau/química , Culinária/métodos , Sementes/química , Biflavonoides/química , Catequina/química , Aromatizantes/química , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Humanos , Odorantes/análise , Polifenóis/química , Proantocianidinas/química , Paladar
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