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1.
Food Chem ; 309: 125769, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31734007

RESUMO

Phenolic compounds are known to bind non-covalently with starch, but the impact of this interaction on the stability of the phenolic compounds through processing and digestion has received little attention. In this study, we examined the recovery of intact phenolic compounds (gallic acid-GA, catechin-CAT and epigallocatechin gallate-EGCG) from processed and digested porridges with different formulations (starch or starch/protein). We observed that phenolics were less degraded in presence of starch only than in presence of starch + proteins. This protection seemed to be linked to the ability of the phenolic compounds to form V-type inclusion complexes with starch, with GA, CAT and EGCG in decreasing order of protection. This work could influence formulation of functional cereal-based foods containing phenolic compounds in order to maximize their retention.


Assuntos
Manipulação de Alimentos/métodos , Fenóis/química , Proteínas/química , Amido/química , Catequina/análogos & derivados , Catequina/química , Catequina/metabolismo , Ácido Gálico/química , Ácido Gálico/metabolismo , Gelatina/química , Gelatina/metabolismo , Fenóis/metabolismo , Proteínas/metabolismo , Amido/metabolismo
2.
Food Chem ; 309: 125718, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31753688

RESUMO

The present study was aimed to investigate the effects of non-covalent and covalent interactions between soy protein isolate (SPI) and different concentrations (1, 2 and 5 mM) of (-)-epigallocatechin gallate (EGCG) regarding the structural and functional properties of the complex. The combination with EGCG caused changes in the secondary structure of SPI. The covalent complexes formed at low concentrations of EGCG tended to form a network structure. Compared with the SPI-EGCG non-covalent complexes, the covalent complexes exhibited higher thermal stability and oxidation resistance and a polyphenol-protective effect. In addition, the corresponding anti-digestive ability of the covalent complexes was strong and would therefore be more stable in the intestinal tract. The findings of this study provide a theoretical reference and research basis for the use of different SPI-polyphenol complexes as functional food ingredients or as bioactive materials.


Assuntos
Catequina/análogos & derivados , Proteínas de Soja/química , Antioxidantes/química , Catequina/química , Catequina/metabolismo , Oxirredução , Tamanho da Partícula , Polifenóis/análise , Estabilidade Proteica , Estrutura Secundária de Proteína , Proteínas de Soja/metabolismo , Temperatura Ambiente
3.
J Photochem Photobiol B ; 199: 111625, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31610430

RESUMO

The cultivated grapevine V. vinifera is a rich source of stilbene compounds such as resveratrol, which are widely believed to provide dietary protection against the development of cardiovascular disease and some forms of cancer. Elicitation is a well-known strategy to increase commercial production of natural products in plant cell suspension culture systems. Callus tissues obtained from berry slices of V. vinifera cv. Shahani grown on an optimized medium were used to develop cell suspension cultures used to study the effects of elicitation on stilbene synthesis. The effect of two light regimes (135.1 µmol. s-1 m-2 radiation, and dark), the concentration of phenylalanine (Phe; 0, 0.1, 0.5 and 1 mM) and of methyl jasmonate elicitor (MeJA; 0 and 25 µM), alone or in combination, were tested. The results showed that cultures grown in darkness resulted in significantly higher levels of the accumulation of total stilbenes (resveratrol + piceid) compared with the high light condition. The combined treatments of dark +1 mM Phe and dark +25 µM MeJA induced the synthesis of high levels of total phenolics, total flavonoids and total stilbenes. Finally, the combined elicitation of dark +1 mM Phe + 25 µM MeJA gave the highest synergistic coefficient (1.24) and proved to be the most effective treatment for the production of total phenolics, total flavonoids, and total stilbenes with mean contents of 384.80 mg GA/g DW, 527.62 mg catechin/g DW and 188.34 µg/g DW, respectively. The results of our study suggest that the combinations of dark together with MeJA and/or Phe can be used as an efficient method for the future scale-up of V. vinifera cell cultures for the production of high value stilbene compounds in a bioreactor system.


Assuntos
Acetatos/metabolismo , Técnicas de Cultura de Células/métodos , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Fenilalanina/metabolismo , Metabolismo Secundário/efeitos dos fármacos , Vitis/citologia , Vias Biossintéticas , Catequina/metabolismo , Linhagem Celular , Condutividade Elétrica , Flavonoides/metabolismo , Glucosídeos/metabolismo , Concentração de Íons de Hidrogênio , Luz , Fenóis/metabolismo , Resveratrol/metabolismo , Estilbenos/metabolismo , Suspensões/metabolismo
4.
Plant Physiol Biochem ; 143: 190-202, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31518850

RESUMO

Temperature is one of the most important environmental factors limiting tea plant growth and tea production. Previously we reported that both Ca2+ and ROS signals play important roles in tea plant cold acclimation. Here, we identified 26 CsCPK transcripts, analyzed their phylogenetic and sequence characters, and detected their transcriptions to monitor Ca2+ signaling status. Tissue-specific expression profiles indicated that most CsCPK genes were constitutively expressed in tested tissues, suggesting their possible roles in development. Cold along with calcium inhibitor assays suggested that CsCPKs are important cold regulators and CsCPK30/5/4/9 maybe the key members. Moreover, LaCl3 or EGTA pre-treatment could result in impaired Ca2+ signaling and compromised cold-responding network, but higher catechins accumulation revealed their potential positive roles in cold responses. Those findings indicated that catechins and other secondary metabolites in tea plant may form an alternative cold-responding network that closely correlated with Ca2+ signaling status.


Assuntos
Camellia sinensis/metabolismo , Catequina/metabolismo , Proteínas Quinases/metabolismo , Camellia sinensis/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Quinases/genética
5.
J Agric Food Chem ; 67(37): 10352-10360, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31503479

RESUMO

The potential for apple peels to mitigate the deleterious effects of a high-fat diet in mice was investigated here. Mice were fed a high-fat diet supplemented with apple powders from three apple varieties or a commercial apple polyphenol. Polyphenols were characterized using colorimetric assays and high-performance liquid chromatography. Mice were tested for standard metabolic parameters. There was a dose response to dietary apple peels, with the higher intake leading to reduced weight gain and adipose tissue mass relative to the lower intake, but none of the treatments were statistically different from the control. The gene expression of liver enzyme stearoyl-CoA desaturase (Scd-1) was correlated with adipose weight, and liver enzyme cytochrome P51 (Cyp51) was downregulated by the apple diets. The feces from a subset of mice were analyzed for polyphenols and for bacteria taxa by next-generation sequencing. The results revealed that the makeup of the fecal microbiota was related to the metabolism of dietary polyphenols.


Assuntos
Biflavonoides/análise , Catequina/análise , Fezes/química , Frutas/metabolismo , Microbioma Gastrointestinal , Malus/metabolismo , Obesidade/dietoterapia , Proantocianidinas/análise , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biflavonoides/metabolismo , Catequina/metabolismo , Dieta Hiperlipídica/efeitos adversos , Frutas/química , Humanos , Masculino , Malus/química , Camundongos , Obesidade/genética , Obesidade/metabolismo , Obesidade/microbiologia , Polifenóis/análise , Polifenóis/metabolismo , Proantocianidinas/metabolismo , Estearoil-CoA Dessaturase/genética , Estearoil-CoA Dessaturase/metabolismo , Esterol 14-Desmetilase/genética , Esterol 14-Desmetilase/metabolismo
6.
Molecules ; 24(17)2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31480459

RESUMO

Theaflavin is a kind of multi-pharmacological and health beneficial black tea factor. The aim of this study is to investigate the mechanisms by which theaflavin interacts with glycosylated and non-glycosylated serum albumins and compares their binding properties. Fluorescence and ultraviolet spectra indicated that theaflavin interacted with native and glycated human serum albumin through a static quenching mechanism and had a higher degree of quenching of human serum albumin. The thermodynamic parameters revealed that the combinations of theaflavin with native and glycated human serum albumin were a spontaneous endothermic reaction, and the hydrophobic force was a major driving force in the interaction process. Zeta potential, particle size, synchronous fluorescence, three-dimensional fluorescence spectroscopy and circular dichroism further clarified the effect of theaflavin on the conformation of human serum albumin structure were more pronounced. In addition, site competition experiments and molecular docking technique confirmed that the binding sites of theaflavin on both native and glycated human serum albumin were bound at site II. This study had investigated the effects of glycation on the binding of HSA with polyphenols and the potential nutriology significance of these effects.


Assuntos
Biflavonoides/metabolismo , Catequina/metabolismo , Albumina Sérica Humana/metabolismo , Aminoácidos/metabolismo , Biflavonoides/química , Sítios de Ligação , Catequina/química , Dicroísmo Circular , Glicosilação , Humanos , Cinética , Simulação de Acoplamento Molecular , Tamanho da Partícula , Albumina Sérica Humana/química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Eletricidade Estática , Termodinâmica
7.
Food Chem ; 301: 125294, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31382111

RESUMO

The interaction of copper complexed with (-)-epigallocatechin-3-gallate (EGCG) and bovine serum albumin (BSA) was investigated using fluorescence, circular dichroism (CD) spectroscopy, HPLC and protein-ligand docking. The fluorescence quenching efficiency of BSA by EGCG was enhanced after EGCG was complexed with copper, and the EGCG-Cu complex exhibited a higher apparent binding affinity (8.88 × 105 M-1) to BSA compared with EGCG alone (5.17 × 105 M-1). The CD experiment showed that both the EGCG-BSA and [EGCG-Cu]-BSA interactions resulted in the unfolding of the secondary structure of the protein. Results of competitive binding experiments confirmed that the location of EGCG and EGCG-Cu complex binding in BSA was site I. Furthermore, molecular modeling was used to identify the amino acid residue in site I and site II that play key roles in this binding interaction. The data suggest that most of the residues involved in the [EGCG-Cu]-BSA reaction belong to the subdomains IIa (site I) of BSA.


Assuntos
Catequina/análogos & derivados , Cobre/química , Soroalbumina Bovina/química , Ligação Competitiva , Catequina/química , Catequina/metabolismo , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Cobre/metabolismo , Ligantes , Simulação de Acoplamento Molecular , Estrutura Secundária de Proteína , Soroalbumina Bovina/metabolismo , Espectrometria de Fluorescência
8.
AAPS PharmSciTech ; 20(6): 250, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31297635

RESUMO

Melanoma is regarded as the fifth and sixth most common cancer in men and women, respectively, and it is estimated that one person dies from melanoma every hour in the USA. Unfortunately, the treatment of melanoma is difficult because of its aggressive metastasis and resistance to treatment. The treatment of melanoma continues to be a challenging issue due to the limitations of available treatments such as a low response rate, severe adverse reactions, and significant toxicity. Natural polyphenols have attracted considerable attention from the scientific community due to their chemopreventive and chemotherapeutic efficacy. It has been suggested that poorly soluble polyphenols such as curcumin, resveratrol, quercetin, coumarin, and epigallocatechin-3-gallate may have significant benefits in the treatment of melanoma due to their antioxidant, anti-inflammatory, antiproliferative, and chemoprotective efficacies. The major obstacles for the use of polyphenolic compounds are low stability and poor bioavailability. Numerous nanoformulations, including solid lipid nanoparticles, polymeric nanoparticles, micelles, and liposomes, have been formulated to enhance the bioavailability and stability, as well as the therapeutic efficacy of polyphenols. This review will provide an overview of poorly soluble polyphenols that have been reported to have antimetastatic efficacy in melanomas.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Melanoma/tratamento farmacológico , Polifenóis/administração & dosagem , Polifenóis/química , Neoplasias Cutâneas/tratamento farmacológico , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Antioxidantes/metabolismo , Disponibilidade Biológica , Catequina/administração & dosagem , Catequina/análogos & derivados , Catequina/química , Catequina/metabolismo , Curcumina/administração & dosagem , Curcumina/química , Curcumina/metabolismo , Humanos , Melanoma/metabolismo , Melanoma/prevenção & controle , Nanopartículas/administração & dosagem , Nanopartículas/química , Nanopartículas/metabolismo , Polifenóis/metabolismo , Quercetina/administração & dosagem , Quercetina/química , Quercetina/metabolismo , Resveratrol/administração & dosagem , Resveratrol/química , Resveratrol/metabolismo , Neoplasias Cutâneas/metabolismo , Solubilidade
9.
Food Funct ; 10(7): 4407-4413, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31282911

RESUMO

Mucosal α-glucosidases from rat intestinal powder were employed, with a step to remove α-amylase, to measure the possibility of different inhibition of catechins, particularly those found in tea, on the four α-glucosidase enzymes. Inhibition of catechins was investigated for the slowing of digestion of glycemic carbohydrates, thus regulating glucose release and absorption. The α-glucosidases were fractionated using size-exclusion chromatography. The partially purified fractions showed higher α-glucosidase activity without any α-amylase activity. Catechins had selective inhibition properties on the α-glucosidases. In particular, (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin gallate (ECG) showed comparably high inhibitory effect on all four individual α-glucosidases, while (-)-epicatechin (EC), and (+)-catechin (C) indicated a more discriminating effect with relatively higher inhibitory effects on sucrase-isomaltase. The findings suggest that catechins differently inhibit the individual subunits of the α-glucosidases, and that they could modulate postprandial blood glucose levels through slowing digestion rate of starch and other glycemic carbohydrates, including sucrose.


Assuntos
Catequina/farmacologia , Intestinos/enzimologia , Membrana Mucosa/metabolismo , alfa-Glucosidases/metabolismo , Animais , Glicemia , Metabolismo dos Carboidratos , Catequina/análogos & derivados , Catequina/metabolismo , Glucose/metabolismo , Hidroxibenzoatos , Ratos , Amido , Especificidade por Substrato , alfa-Amilases/metabolismo
10.
J Agric Food Chem ; 67(32): 9079-9087, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31353905

RESUMO

Organic anion transporting polypeptides (OATPs) 1B1 and 1B3 are two highly homologous transporters expressed in the human liver. However, epigallocatechin gallate (EGCG), which is the most predominant catechin in green tea, has opposite effects on the function of OATP1B1 and OATP1B3. In the present study, the critical structural domains and amino acid residues for the activation of OATP1B3 by EGCG have been determined by characterizing the function of a series of OATP1B3-derived chimeric transporters, site-directed mutagenesis, and kinetic studies. Our results showed that G45 and F555 in transmembrane domains 1 and 10 are the most important amino acid residues for OATP1B3 activation. Kinetic studies showed that the activation of OATP1B3 by EGCG at a low substrate concentration was due to its increased substrate binding affinity. However, EGCG caused increased Km and decreased Vmax for 1B3-G45A and 1B3-F555H. The flexibility at position 45 and aromaticity at position 555 might be important for OATP1B3 activation. While 1B3-G45A and 1B3-F555H could not be activated by EGCG, their transport activity for EGCG was comparable to that of wild-type OATP1B3. In conclusion, the present study elucidated the molecular mechanism for OATP1B3 activation by EGCG.


Assuntos
Catequina/análogos & derivados , Extratos Vegetais/metabolismo , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/química , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/metabolismo , Motivos de Aminoácidos , Camellia sinensis/química , Catequina/química , Catequina/metabolismo , Células HEK293 , Humanos , Cinética , Fígado/metabolismo , Transportador 1 de Ânion Orgânico Específico do Fígado/química , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Transportador 1 de Ânion Orgânico Específico do Fígado/metabolismo , Modelos Moleculares , Extratos Vegetais/química , Domínios Proteicos , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/genética
11.
Int J Mol Sci ; 20(15)2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31349535

RESUMO

Over the last three decades, green tea has been studied for its beneficial effects, including anti-cancer, anti-obesity, anti-diabetes, anti-inflammatory, and neuroprotective effects. At present, a number of studies that have employed animal, human and cell cultures support the potential neuroprotective effects of green tea catechins against neurological disorders. However, the concentration of (-)-epigallocatechin gallate (EGCG) in systemic circulation is very low and EGCG disappears within several hours. EGCG undergoes microbial degradation in the small intestine and later in the large intestine, resulting in the formation of various microbial ring-fission metabolites which are detectable in the plasma and urine as free and conjugated forms. Recently, in vitro experiments suggested that EGCG and its metabolites could reach the brain parenchyma through the blood-brain barrier and induce neuritogenesis. These results suggest that metabolites of EGCG may play an important role, alongside the beneficial activities of EGCG, in reducing neurodegenerative diseases. In this review, we discuss the function of EGCG and its microbial ring-fission metabolites in the brain in suppressing brain dysfunction. Other possible actions of EGCG metabolites will also be discussed.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Catequina/farmacologia , Extratos Vegetais/farmacologia , Chá/química , Animais , Barreira Hematoencefálica/metabolismo , Catequina/análogos & derivados , Catequina/química , Catequina/metabolismo , Cognição/efeitos dos fármacos , Humanos , Estrutura Molecular , Neurogênese/efeitos dos fármacos , Permeabilidade , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Relação Estrutura-Atividade
12.
Oxid Med Cell Longev ; 2019: 4750795, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31316718

RESUMO

This study was designed to unravel the role of Lactobacillus rhamnosus in the bioconversion of cranberry proanthocyanidins and cytotoxicity of resulting metabolites to hepatocellular carcinoma HepG2 cells. Crude (CR) and flavonol+dihydrochalcone- (FL+DHC-), anthocyanin- (AN-), proanthocyanidin- (PR-), and phenolic acid+catechin- (PA+C-) rich fractions were subjected to fermentation with L. rhamnosus at 37°C for 12, 24, and 48 h under anaerobic conditions. The major metabolites produced by bioconversion of polyphenols were 4-hydroxyphenylacetic acid, 3-(4-hydroxyphenyl)propionic acid, hydrocinnamic acid, catechol, and pyrogallol. Furthermore, cytotoxicity of the biotransformed extracts was compared to their parent extracts using human hepatocellular carcinoma HepG2 cells. The results showed that PR-biotransformed extract completely inhibited HepG2 cell proliferation in a dose- and time-dependent manner with IC50 values of 47.8 and 20.1 µg/mL at 24 and 48 h, respectively. An insight into the molecular mechanisms involved revealed that the cytotoxic effects of PR at 24 h incubation were mitochondria-controlled and not by proapoptotic caspase-3/7 dependent. The present findings suggest that the application of a bioconversion process using probiotic bacteria can enhance the pharmacological activities of cranberry proanthocyanidins by generating additional biologically active metabolites.


Assuntos
Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Lactobacillus rhamnosus/metabolismo , Proantocianidinas/metabolismo , Proantocianidinas/farmacologia , Probióticos/metabolismo , Catequina/metabolismo , Catequina/farmacologia , Proliferação de Células/efeitos dos fármacos , Fermentação , Células Hep G2 , Humanos , Hidroxibenzoatos/metabolismo , Hidroxibenzoatos/farmacologia , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologia , Polifenóis/metabolismo , Polifenóis/farmacologia
13.
J Recept Signal Transduct Res ; 39(1): 18-27, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31223050

RESUMO

Epigallocatechin gallate (EGCG) is a major polyphenols of green tea may have the possibility to inhibit epidermal growth factor receptor (EGFR) activity and lead to reduce non-small cell lung cancer (NSCLC) progression. However, EGCG has some toxic features; moreover, there is a lack of explorations into the molecular interaction mechanisms of EGCG and the EGFR. In this examination, integration of quantitative structure-activity relationship (QSAR) modeling, pharmacophore-based virtual screening, and ensemble docking approaches were used to predict potential novel EGCG analogs as effective EGFR inhibitors. QSAR modeling of logP and logS predictions and toxicity endpoint investigation for a set of 82 compounds were shown good predictive ability and robustness from the applicability domain and confusion matrix elucidations. Virtual screening and docking studies revealed that seven high potential EGCG analogs as strong EGFR binders. Molecular interactions interpretations indicated some insights into the structural features of ligands that efficiently interfere with mutation possible residues (Gly719 and Thr790) of the EGFR. The hydrogen bonds, hydrophobic interactions, atomic π-cation interactions and salt bridges of ligands are contributing additional stability to receptor structure, which can lead to blocking the intracellular protein-tyrosine kinase activity, including EGFR associated pathways activation in NSCLC. Therefore, this can characterize as a block-cluster mechanism between EGCG analogs and EGFR complexes. In silico anti-EGFR and anticancer activity predictions suggested that, ligands could act as promising pharmacological, anticancer, and drug-like templates of EGFR towards moderating the NSCLC progressions. These results and provided pinpoints could be beneficial to recognize probable therapeutic targets for NSCLC therapy.


Assuntos
Catequina/análogos & derivados , Simulação por Computador , Modelos Moleculares , Inibidores de Proteínas Quinases/metabolismo , Relação Quantitativa Estrutura-Atividade , Catequina/química , Catequina/metabolismo , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , Ligantes , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica , Inibidores de Proteínas Quinases/química , Transdução de Sinais
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 222: 117213, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31177010

RESUMO

The interactions of (-)-epigallocatechin-3-Gallate (EGCG) and anthracycline drugs (doxorubicin, DOX and epirubicin, EPI) alone or in combination with human serum albumin (HSA) under physiological condition were studied by fluorescence spectroscopy, UV-vis absorption spectroscopy, circular dichroism (CD) spectroscopy, and dynamic light scattering (DLS). The cytotoxic activity of the single drug, combined drugs, and their complexes with HSA against human cervical cancer HeLa cell line was determined by MTT assay. Fluorescence quenching result and difference spectra of UV absorption revealed the formation of static complex between EGCG, DOX, or EPI and HSA. The binding of EGCG with HSA was driven by both enthalpy and entropy while the binding of DOX or EPI was mainly entropy driven. The nature of binding was expounded based on the effect of sodium chloride, tetrabutylammonium bromide, and sucrose which interfere in electrostatic, hydrophobic, and hydrogen bonding interactions, respectively. Site marker competitive experiments combined with synchronous fluorescence spectra showed that these three ligands mainly bound to subdomain IIA of HSA and were closer to tryptophan residues. In EGCG + DOX/EPI + HSA ternary system, the effect of one drug on the binding ability of another drug was discussed. The influences of the individual and combined binding of EGCG and DOX/EPI on the secondary structure and particle size of HSA were investigated by CD spectroscopy and DLS, respectively. Moreover, the synergistic cytotoxicity of EGCG and DOX/EPI as well as their complexes with HSA were discussed. Obtained results would provide beneficial information on the combination of EGCG and anthracyclines in clinic.


Assuntos
Antineoplásicos/farmacologia , Catequina/análogos & derivados , Doxorrubicina/farmacologia , Epirubicina/farmacologia , Albumina Sérica Humana/metabolismo , Antraciclinas/metabolismo , Antraciclinas/farmacologia , Antibióticos Antineoplásicos/metabolismo , Antibióticos Antineoplásicos/farmacologia , Anticarcinógenos/metabolismo , Anticarcinógenos/farmacologia , Antineoplásicos/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica , Catequina/metabolismo , Catequina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Doxorrubicina/metabolismo , Entropia , Epirubicina/metabolismo , Células HeLa , Humanos , Neoplasias/tratamento farmacológico , Ligação Proteica , Espectrometria de Fluorescência
15.
J Med Food ; 22(8): 779-788, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31210578

RESUMO

Green tea is reported to exert beneficial effects on metabolic disorders through the regulation of lipid metabolism. On the contrary, fermented food products have been introduced to improve human health by modulating immune response and energy metabolism. To maximize health benefit, we applied fermentation processing to green tea. Fermented green tea extract (FGT) inhibited adipogenesis and lipogenesis in cultured adipocytes, whereas it augmented mRNA expression of fatty acid oxidation-related genes in differentiated myocytes. In diet-induced obese mice, FGT blunted body weight and fat mass gain by 69.7% and 56.7%, respectively. FGT also improved circulating triglyceride concentrations by 32.6%. Similar to in vitro results, FGT suppressed lipogenesis and promoted lipid catabolism in peripheral tissues. In addition, FGT administration modulated the composition of certain gut microbiota which are associated with obesity and related metabolic disorders. Among the various components of FGT, gallocatechin gallate is suggested to mediate the effect of FGT on lipid metabolism. Taken together, we propose FGT as a novel functional food to benefit human health by controlling adiposity and lipid metabolism.


Assuntos
Adipócitos/efeitos dos fármacos , Catequina/análogos & derivados , Hipertrigliceridemia/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Células Musculares/efeitos dos fármacos , Obesidade/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Adipócitos/metabolismo , Animais , Bacillus subtilis/metabolismo , Camellia sinensis/química , Camellia sinensis/metabolismo , Camellia sinensis/microbiologia , Catequina/administração & dosagem , Catequina/análise , Catequina/metabolismo , Fermentação , Humanos , Lipogênese/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares/metabolismo , Obesidade/metabolismo , Extratos Vegetais/análise , Extratos Vegetais/metabolismo , Triglicerídeos/metabolismo
16.
J Food Sci ; 84(7): 1746-1757, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31206686

RESUMO

'Anji Baicha' (Camellia sinensis) is a low-temperature-sensitive tea variety. During the development of young shoots, the leaves of 'Anji Baicha' exhibit periodic albinism. The quality of 'Anji Baicha' is closely related to the color of the fresh leaves, with whiter leaves affording a higher amino acid content and superior sensory quality after processing. However, the metabolic mechanism of its quality formation is still unclear. In this study, we analyzed the metabolomic changes of young shoots of 'Anji Baicha' and screened for metabolic markers that may be involved in the periodic albinism. Positive- and negative-mode UPLC-QTOF-MS was applied to the metabolomic analysis of young leaves of 'Anji Baicha' during three developmental stages (i.e., the pre-albescent, albescent, and regreening stages). The results revealed significant differences in the metabolic profiles of the young leaves at the three stages. The differential metabolites were mainly related to the pathways of flavonoid, phenylpropanoid, and amino acid biosynthesis. The concentrations of several amino acids (primarily l-theanine, l-glutamate, N2 -acetyl-l-ornithine, l-aspartic acid, d-proline, l-glutamine, l-leucine, and pyroglutamic acid) and 12-OPDA were significantly higher in the albescent stage. In contrast, during the albescent stages, the concentrations of several carbohydrates (d-fructose, ß-d-galactopyranose, 3-O-fucopyranosyl-2-acetamido-2-deoxyglucopyranose, galactose-ß-1, 4-xylose acetyl-maltose, and 2-fucosyllactose) were significantly lower. Moreover, catechins (mainly epigallocatechin and catechin derivatives), dimeric catechins (primarily proanthocyanidins), and flavonol and flavonol/flavone glycosides (mainly kaempferol, myricetin, quercetin, cyanidin, and delphinidin glycosides) were detected at the highest levels in the regreening or pre-albescent stages. The obtained results enhance the current understanding of the metabolic mechanisms of periodic albinism and quality development formation in 'Anji Baicha'. PRACTICAL APPLICATION: The obtained results not only provide information regarding differential metabolites but also advance the understanding of the mechanism of periodic albinism in 'Anji Baicha' at the metabolite level and open up new possibilities for the genetic improvement of tea cultivars.


Assuntos
Camellia sinensis/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Aminoácidos/análise , Aminoácidos/metabolismo , Camellia sinensis/química , Camellia sinensis/metabolismo , Catequina/análogos & derivados , Catequina/análise , Catequina/metabolismo , Cromatografia Líquida , Glutamatos/análise , Glutamatos/metabolismo , Glicosídeos/análise , Quempferóis/análise , Quempferóis/metabolismo , Metaboloma , Metabolômica , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Brotos de Planta/química , Brotos de Planta/metabolismo , Espectrometria de Massas em Tandem
17.
Ecotoxicol Environ Saf ; 180: 374-383, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31102845

RESUMO

Ozone (O3) can cause oxidative stress in plants and humans. Catechin is an antioxidant that enriches tea and can probably increase O3 tolerance in plants. To investigate the mechanism of catechin to alleviate O3 stress in plants, Zamiocalcus zamiifolia (an efficient plant for O3 phytoremediation) was sprayed with 5 mM catechin and was used to expose O3 (150-250) under long-term operation (10 cycles). We investigated whether exogenous catechin could enhance O3 removal and alleviate O3 stress through a balanced redox state in plants. Z. zamiifolia sprayed with catechin exhibited higher O3 removal (80.27±3.12%), than Z. zamiifolia without catechin (50.03±2.68%). O3 in the range of 150-250 ppb led to stress in plants, as shown by an increased malondialdehyde content (MDA) and salicylic acid (SA). Whereas under the presence of O3, exogenous catechin could maintain the MDA content and inhibit SA accumulation. Under Z. zamiifolia+catechin+O3 conditions, catechin reacted with O3, which led to the formation of catechin-quinone. The formation of catechin-quinone was confirmed by the depletion of reduced glutathione content (GSH). This catechin-quinone could induce GST and APX genes that are up-regulated approximately 35- and 5-fold, respectively. Hence, Z. zamiifolia+catechin+O3 conditions had higher performance for coping with oxidative stress than did Z. zamiifolia+O3 conditions. This evidence demonstrates that catechin could enhance O3 removal through a balanced redox state in plant cells. Finally, the application of tea extract for enhanced O3 removal is also shown in this study.


Assuntos
Poluentes Atmosféricos/toxicidade , Antioxidantes/metabolismo , Araceae/efeitos dos fármacos , Catequina/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ozônio/toxicidade , Araceae/enzimologia , Araceae/metabolismo , Benzoquinonas/metabolismo , Biodegradação Ambiental , Clorofila/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Oxirredução , Ácido Salicílico/metabolismo
18.
Food Funct ; 10(5): 2958-2969, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31073569

RESUMO

Cacao (Theobroma cacao) has a significant polyphenol content and has been reported to elicit anti-obesity effects. Previous studies have focused on the properties of cacao extract and procyanidins, while the potential mechanisms have not been fully elucidated. Here, we investigated the inhibitory effects of procyanidin metabolites on adipogenic cocktail-induced adipogenesis and lipogenesis in 3T3-L1 preadipocytes. It was observed that 5-(3',4'-dihydroxyphenyl)-γ-valerolactone (DHPV), a major procyanidin metabolite, exhibited the greatest inhibitory effects on adipogenesis and lipogenesis. DHPV dose-dependently reduced the expression levels of proteins involved in adipogenesis including peroxisome proliferator-activated receptor γ (PPAR γ) and CCAT/enhancer-binding protein α (C/EBP α), as well as lipogenesis-related factors such as fatty acid synthase and acetyl-CoA carboxylase. These inhibitory effects were primarily due to G1 phase arrest and the suppression of cell proliferation during mitotic clonal expansion, the early stage of adipogenesis. In an extensive kinase array, DHPV directly suppressed activation of the CDK2/cyclin O complex, and inhibited the phosphorylation of C/EBP ß, which is responsible for the induction of PPAR γ and C/EBP α. Taken together, these findings suggest that DHPV is a highly biologically active compound with potential anti-obesity effects and works by inhibiting the intracellular lipid content and cell differentiation.


Assuntos
Adipogenia/efeitos dos fármacos , Biflavonoides/metabolismo , Cacau/química , Catequina/metabolismo , Ciclo Celular/efeitos dos fármacos , Quinase 2 Dependente de Ciclina/metabolismo , Ciclinas/metabolismo , Lactonas/farmacologia , Proantocianidinas/metabolismo , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Quinase 2 Dependente de Ciclina/genética , Ciclinas/genética , Lactonas/metabolismo , Camundongos , Células NIH 3T3 , PPAR gama/genética , PPAR gama/metabolismo , Fosforilação
19.
Food Funct ; 10(5): 2997-3007, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31086895

RESUMO

(-)-Epigallocatechin-3-gallate (EGCG), a major phenolic constituent of tea, has been shown to have biological activity within inflammatory pathways involved with food allergies and intolerances. Proposed mechanisms for this effect include sequestration and structural modification of immunostimulatory proteins as a result of interactions with EGCG. The present study employs biophysical techniques including dynamic light scattering, circular dichroism and nuclear magnetic resonance to elucidate the likely mechanism(s) by which EGCG interacts with α2-gliadin (57-89) (α2g), an immunodominant peptide in celiac disease pathogenesis. We demonstrate that EGCG interacts with α2g in a multi-phase reaction driven by non-specific binding, resulting in the formation of polydisperse EGCG/α2g complexes which induce changes in peptide structure. We also show that these interactions occur at a range of pH levels associated with digestion, including pH 2.0, 6.8 and 7.5. Based on previous reports of binding specificity of enzymes and antigen presenting cells in celiac disease pathogenesis, our results provide foundational support for EGCG to prevent recognition of immunostimulatory gliadin epitopes by the body and thus prevent the inflammatory and autoimmune response associated with celiac disease.


Assuntos
Catequina/análogos & derivados , Doença Celíaca/metabolismo , Gliadina/química , Fragmentos de Peptídeos/química , Extratos Vegetais/química , Camellia sinensis/química , Camellia sinensis/metabolismo , Catequina/química , Catequina/metabolismo , Dicroísmo Circular , Humanos , Concentração de Íons de Hidrogênio , Fragmentos de Peptídeos/metabolismo , Extratos Vegetais/metabolismo
20.
J Agric Food Chem ; 67(24): 6716-6724, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31135151

RESUMO

Insect attack is known to induce a high accumulation of volatile metabolites in tea ( Camellia sinensis). However, little information is available concerning the effect of insect attack on tea quality-related nonvolatile specialized metabolites. This study aimed to investigate the formation of characteristic nonvolatile specialized metabolites in tea leaves in response to attack by major tea insects, namely, tea green leafhoppers and tea geometrids, and determine the possible involvement of phytohormones in metabolite formation resulting from insect attack. Both tea green leafhopper and tea geometrid attacks increased the jasmonic acid and salicylic acid contents. The abscisic acid content was only increased under tea green leafhopper attack, perhaps due to special continuous piercing-sucking wounding. Tea green leafhopper attack induced the formation of theaflavins from catechins under the action of polyphenol oxidase, while tea geometrid attack increased the l-theanine content. Exogenous phytohormone treatments can affect the caffeine and catechin contents. These results will help to determine the influence of major tea pest insects on important tea quality-related metabolites and enhance understanding of the relationship of phytohormones and quality-related nonvolatile metabolite formation in tea exposed to tea pest insect attacks.


Assuntos
Camellia sinensis/metabolismo , Hemípteros/fisiologia , Folhas de Planta/química , Folhas de Planta/parasitologia , Animais , Biflavonoides/análise , Biflavonoides/metabolismo , Camellia sinensis/química , Camellia sinensis/parasitologia , Catequina/análise , Catequina/metabolismo , Ciclopentanos/análise , Ciclopentanos/metabolismo , Glutamatos/análise , Glutamatos/metabolismo , Oxilipinas/análise , Oxilipinas/metabolismo , Reguladores de Crescimento de Planta/química , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/metabolismo , Ácido Salicílico/análise , Ácido Salicílico/metabolismo
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