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1.
J Agric Food Chem ; 67(32): 8847-8854, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31328515

RESUMO

Microbiome has been revealed as a key element involved in maintaining the circadian rhythms. Oolong tea polyphenols (OTP) has been shown to have potential prebiotic activity. Therefore, this study focused on the regulation mechanisms of OTP on host circadian rhythms. After 8 weeks of OTP administration, a large expansion in the relative abundance of Bacteroidetes with a decrease in Firmicutes was observed, which reflected the positive modulatory effect of OTP on gut flora. In addition, Kyoto Encyclopedia of Genes and Genomes pathways of ATP-binding cassette transporters, two-component system, and the biosynthesis of amino acids enriched the most differentially expressed genes after OTP treatment. Of the differentially expressed proteins identified, most were related to metabolism, genetic information processing, and environmental information processing. It underscores the ability of OTP to regulate circadian rhythm by enhancing beneficial intestinal microbiota and affecting metabolic pathways, contributing to the improvement of host microecology.


Assuntos
Camellia sinensis/química , Transtornos Cronobiológicos/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Transtornos Cronobiológicos/microbiologia , Transtornos Cronobiológicos/fisiopatologia , Modelos Animais de Doenças , Feminino , Humanos , Intestinos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Chá/química
2.
Food Chem ; 298: 125030, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260978

RESUMO

Plant extracts from rosemary (RE), green tea (GTE), and maté (ME) were compared for the protection against iron-induced oxidation in porcine homogenates at total phenolic concentrations from 25 to 250 ppm. Lipid oxidation as indicated by TBARS was in all cases sufficiently suppressed, especially for RE. Hydrophobic RE retarded overall oxidation in the homogenates with an inverted dose-dependent response. Optimum delay of oxygen consumption was found at the lowest concentration applied, similar to protection against thiols and formation of protein radicals as measured by ESR, whereas the high concentration increased oxygen consumption and caused additionally thiol loss possibly due to thiol-quinone interactions, generating protein-phenol complexes. Hydrophilic ME or GTE increased the initial oxygen consumption rate as an indication of prooxidant activities at elevated concentrations. However, they were found to protect myoglobin and protein at those high concentrations with GTE being more efficient, possibly due to better chelation effect.


Assuntos
Antioxidantes/farmacologia , Músculo Esquelético/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Antioxidantes/química , Relação Dose-Resposta a Droga , Ilex paraguariensis/química , Ferro/química , Ferro/toxicidade , Metabolismo dos Lipídeos/efeitos dos fármacos , Músculo Esquelético/metabolismo , Mioglobina/metabolismo , Oxirredução , Fenóis/metabolismo , Extratos Vegetais/química , Rosmarinus/química , Suínos , Chá/química
3.
J Oleo Sci ; 68(7): 689-697, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257353

RESUMO

In this study, tea polyphenols (TP) was added to a soy protein isolate (SPI) to prepare nanoemulsions by ultra-high pressure homogenization (UHPH). The nanoemulsions were characterized by a confocal laser scanning electron microscopy, infrared spectroscopy, dynamic rheometer and size-potential analyzer. The effects of TP on the hydrophobicity, emulsifiability, particle size, potential and antioxidant capacity of the prepared nanoemulsions were investigated. The properties of the nanoemulsions with different concentrations of TP were analyzed. The results indicated that ultra-high pressure homogenization treatment contributed to the formation of the SPI-TP complex that showed higher antioxidant activity. The nanoemulsions with good emulsifying properties and high DPPH scavenging ability at the concentration of TP ranged from 0.15-0.20g / mL. Furthermore, nanoemulsions prepared in this way also had a uniform particle size. Therefore, this nanoemulsions exhibited a good potential to act as an efficient emulsifier.


Assuntos
Antioxidantes/química , Proteínas de Soja/química , Chá/química , Antioxidantes/farmacologia , Fenômenos Químicos , Relação Dose-Resposta a Droga , Emulsificantes , Emulsões , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas , Tamanho da Partícula
4.
Int J Nanomedicine ; 14: 4277-4292, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239679

RESUMO

Background: Kidney stone formation is closely related to renal epithelial cell damage and the adhesion of calcium oxalate crystals to cells. Methods: In this research, the adhesion of human kidney proximal tubular epithelial cells (HK-2) to calcium oxalate monohydrate crystals with a size of approximately 100 nm was studied. In addition, the inhibition of crystal adhesion by four tea polysaccharides (TPS0, TPS1, TPS2, and TPS3) with the molecular weights of 10.88, 8.16, 4.82, and 2.31 kDa, respectively were compared. Results: When oxalic acid-damaged HK-2 cells were repaired, cell viability increased. By contrast, reactive oxygen species level, phosphatidylserine eversion, and osteopontin expression decreased, thus indicating that tea polysaccharides have a repairing effect on damaged HK-2 cells. Moreover, after repairing the damaged cells, the amount of adherent crystals was reduced. The repair effect of tea polysaccharides is closely related to molecular weight, and TPS2 with the moderate molecular weight displayed the best repair effect. Conclusion: These results suggest that tea polysaccharides, especially TPS2, may inhibit the formation and recurrence of calcium oxalate kidney stones.


Assuntos
Oxalato de Cálcio/farmacologia , Polissacarídeos/farmacologia , Chá/química , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cristalização , Fluorescência , Humanos , Nanopartículas/química , Osteopontina/metabolismo , Espécies Reativas de Oxigênio/metabolismo
5.
Food Chem ; 297: 124885, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253299

RESUMO

Certain food properties (ex.: pH, polyphenolic composition) can inhibitdigestive amylases and thereby slow down starch digestion. Our aim was twofold. (1) To determine the impact of21 beverages and condiments (coffees, teas, wines, vinegars and lemon juice)on salivary and pancreatic amylolysis: inhibition ranged from 10% to 100%in our experimental conditions. (2) To investigate the effect of one black tea and lemon juice (selected for their strong inhibitory capacity) on starch hydrolysis during dynamicoro-gastro-intestinal digestion of bread. Compared to water (control), the effect of black tea was limited to a ≈20% reduction of released oligosaccharides during the intestinal phase. Lemon juice had a remarkable effect, completely interrupting gastric amylolysis by salivary amylase via a preliminary acidification of gastric contents. These results provide a strong biochemical rationale for the development of dietary strategies to improve the glycaemic impact of starch-rich meals which could be tested in vivo.


Assuntos
Amilases/metabolismo , Camellia sinensis/química , Sucos de Frutas e Vegetais/análise , Amido/metabolismo , Chá/química , Amilases/antagonistas & inibidores , Pão/análise , Camellia sinensis/metabolismo , Humanos , Hidrólise , Pâncreas/enzimologia , Saliva/enzimologia , Chá/metabolismo
6.
Food Chem ; 297: 124962, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253288

RESUMO

Ferrocene-based nanoporous organic polymer (Fc-NOP) was used as solid-phase extraction (SPE) adsorbent and showed excellent adsorption capacity for chlorophenols (CPs) compared with commercial C18 and multi-walled carbon nanotubes. Then, a SPE method with Fc-NOP packed cartridge combined with HPLC-UV detection was developed to determine CPs in tap water, black tea drinks and peach juice samples. Under optimal conditions, the detection limits of the method measured at the signal to noise ratio of 3 (S/N = 3) were 0.04-0.06 ng mL-1 for tap water and 0.10-0.20 ng mL-1 for black tea drinks and peach juice samples. Satisfactory method recoveries were achieved in the range of 87.6-119% with relative standard deviations of 3.11-7.83%. Result proved that this method was a sensitive and efficient method for determination of trace CPs in foods. The extraction result for more other compounds confirmed that the developed method had a great application potential for analysis of other trace pollutants in food samples.


Assuntos
Clorofenóis/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Polímeros/química , Extração em Fase Sólida/métodos , Adsorção , Clorofenóis/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Compostos Ferrosos/química , Análise de Alimentos/instrumentação , Água Doce/análise , Sucos de Frutas e Vegetais/análise , Limite de Detecção , Metalocenos/química , Nanoporos , Nanotubos de Carbono/química , Prunus persica/química , Extração em Fase Sólida/instrumentação , Chá/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
7.
Food Chem ; 297: 124947, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253290

RESUMO

Newly developed combination of magnetic cobalt particles based dispersive solid-phase microextraction (Co-MP-DSPME) and slotted quartz tube attached flame atomic absorption spectrometry (SQT-FAAS) was utilized to determine lead at trace levels in tea samples. Co-MPs' adsorbent properties were tested and validated for their selectiveness to lead. Only with a few and short extraction steps (i.e. adding MPs, mixing, decanting and eluting) analyte was extracted from sample solution rapidly and efficiently. Limit of detection (LOD) and limit of quantification (LOQ) for the developed method (Co-MP-DSPME-SQT-FAAS) were found to be 7.77 µg/L and 25.9 µg/L, respectively. Matrix matching strategy was performed and outcomes indicated that the developed method is applicable with the high percent recovery values of 110.1 ±â€¯4.5 and %102.9 ±â€¯4.2 for 100 and 300 µg/kg lead standard spiked black tea samples, respectively. The method was also applied to standard reference material to check the accuracy of the method.


Assuntos
Contaminação de Alimentos/análise , Chumbo/análise , Microextração em Fase Sólida/métodos , Espectrofotometria Atômica/métodos , Chá/química , Cobalto/química , Análise de Alimentos/métodos , Limite de Detecção , Quartzo/química , Sensibilidade e Especificidade , Microextração em Fase Sólida/instrumentação , Espectrofotometria Atômica/instrumentação
8.
Food Chem ; 297: 124950, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253304

RESUMO

Leaves of plants from the genus Camellia (CAM) are used to make tea; however, there are limited data that compares chemical composition and biological activity of CAM cultivars used to make six tea types. Fourteen CAM cultivars were analyzed by HPLC and UPLC-Q-TOF-MS/MS and biological activity was assessed in a cell growth assay. Tea bioactives and cell growth inhibition varied 2-4 fold. EGCG was the dominant catechin that predicted the magnitude of growth inhibition. However, pure EGCG did not fully account for inhibitory activity suggesting that it may serve as a chemical marker for bioefficacy. As an unbiased characterization of differences in chemical composition among CAM, individual metabolomes were determined and used to generate principle components (PC). PC's from the metabolome were complementary to those from targeted analyses of tea bioactives and were predictive of growth inhibition. This study provides a frame work for identifying CAM cultivars with beneficial traits.


Assuntos
Camellia sinensis/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Camellia/química , Catequina/análogos & derivados , Catequina/análise , Catequina/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/métodos , Análise de Alimentos/estatística & dados numéricos , Humanos , Metaboloma , Extratos Vegetais/química , Análise de Componente Principal , Espectrometria de Massas em Tandem , Chá/química
9.
Anal Bioanal Chem ; 411(20): 5309-5316, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31254053

RESUMO

A highly selective and sensitive fluorescent probe for optosensing lambda-cyhalothrin (LC) was prepared. The probe was based on sulfur-doped carbon dots (CDs) coated with molecularly imprinted polymers (MIPs). Doping the CDs with sulfur and modifying the surfaces of the CDs with an ionic liquid enhanced the performance of the fluorescent probe. The selectivity of the probe was improved through the application of molecular imprinting technology utilizing acrylamide and 1-vinyl-3-butylimidazolium tetrafluoroborate [VBIm][BF4] as functional monomers. The resulting probe was used to detect LC, which is a pesticide residue, in vegetables and tea. Under optimal detection conditions, the linear range of the probe was found to be 1-150 µg kg-1 and the limit of detection to be 0.5 µg kg-1 by analyzing excitation/emission maxima at 350/450 nm. The developed method was successfully used to determine LC in vegetables and tea, yielding recoveries of 98.90-116.93%. These results suggest that this fluorescent probe based on MIP-coated, room-temperature ionic-liquid-sensitized, sulfur-doped carbon dots has great potential to be utilized for the precise detection of LC in complex samples. Graphical abstract.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Líquidos Iônicos/química , Impressão Molecular/métodos , Nitrilos/análise , Polímeros/química , Piretrinas/análise , Artefatos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Chá/química , Termodinâmica , Verduras/química , Difração de Raios X
10.
Gene ; 711: 143940, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31226279

RESUMO

Tea plant (Camellia sinensis) is an important leaf-type woody crop used to produce non-alcoholic beverages all over the world. Tea is one of the oldest and most popular non-alcoholic beverages in the world, and long-term tea drinking has numerous healthful for humans due to many of the important secondary metabolites, such as polyphenols and theanine. Theanine and polyphenols are also closely related to tea flavor and tea aroma, which is usually as the standard for judging tea quality. The growth of tea plants and quality of teas are susceptible to adversity abiotic and biotic stresses, such as low temperatures and pests. Consequently, this review focus on the research progress of key genes related to the stress resistance and material metabolism of tea plants in recent years. We aim at comprehensively understanding the growth and metabolism of tea plants and their relationship with the external environment, so as to provide an in-depth and broad theoretical support for the breeding of excellent tea plant varieties.


Assuntos
Camellia sinensis/fisiologia , Proteínas de Plantas/genética , Camellia sinensis/genética , Regulação da Expressão Gênica de Plantas , Polifenóis/biossíntese , Estresse Fisiológico , Chá/química , Chá/genética
11.
Se Pu ; 37(6): 597-604, 2019 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-31152509

RESUMO

To efficiently and quickly detect free amino acid components in tea, a method using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. With the optimization of mass spectrometry, chromatographic conditions, and amino-acid extraction conditions, a total of 20 free amino acids were identified using 5 mmol/L ammonium acetate aqueous solution containing 0.2% (v/v) formic acid and methanol as mobile phases for gradient elution and detected by electrospray ionization (ESI) and positive-ion scanning. The results showed that all calibration curves expressed good linearities. Theanine (Thea), Arg, Asn, and Asp were in the range of 50-500 µg/L. The other amino acids were in the range of 10-250 µg/L with all correlation coefficients ≥ 0.99. The average recoveries were between 92.3% and 109.2%. The relative standard deviation (RSDs) were between 2.00% and 9.88%. The limits of detection (LODs) were 0.001-0.011 mg/L, and the limits of quantification (LOQs) were 0.010-0.053 mg/L. The method is sensitive, accurate, and has good repeatability and stability. The method can effectively detect 20 types of amino acids and amino components in tea leaves from the samples of green tea, white tea, and black tea.


Assuntos
Aminoácidos/análise , Análise de Alimentos/métodos , Chá/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas em Tandem
12.
Se Pu ; 37(6): 605-611, 2019 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-31152510

RESUMO

A method was developed for the determination of pyrethroid pesticides in tea by accelerated solvent extraction (ASE) combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The target compounds were extracted from tea using n-hexane and acetone (2:1, v/v) for 5 min at 10.34 MPa and 80℃ via a single cycle of accelerated solvent extraction. The extract was purified by GCB/NH2 and Florisil columns, analyzed by UPLC-MS/MS in positive electrospray ionization (ESI+) and multiple reaction monitoring (MRM) modes, and quantified by the external standard method. Regression analysis revealed that the linear relationships between mass concentration and peak area are significant for the 10 pyrethroid pesticides, and the correlation coefficients (r) are all not less than 0.9995. The limits of detection (LOD) of the 10 pyrethroid pesticides ranged from 0.5 µg/kg to 5.0 µg/kg and the limits of quantification (LOQ) ranged from 1.6 µg/kg to 16.6 µg/kg. The recoveries of all the pesticides ranged from 68.7% to 103.8% at the spiked levels of LOQ, 0.4 mg/kg and maximum residue limit (MRL) (added 1 mg/kg without MRL) with RSDs ranging from 0.8% to 13.2% (n=7). The proposed method is simple, rapid, sensitive, and accurate, and could be effective for trace analysis of pyrethroid pesticides in tea.


Assuntos
Contaminação de Alimentos/análise , Praguicidas/análise , Piretrinas/análise , Chá/química , Cromatografia Líquida de Alta Pressão , Solventes , Espectrometria de Massas em Tandem
13.
J Cancer Res Clin Oncol ; 145(8): 1987-1998, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31214760

RESUMO

PURPOSE: Based on the poor prognosis of drug resistance in pediatric acute lymphoblastic leukemia (ALL) and adverse effects of chemotherapy, this study was aimed to evaluate the effect of several herbal extracts on leukemic cells. METHODS: Two subtypes of T- and B-ALL cell lines, followed by ALL primary cells were treated with cinnamon, ginger, and green tea extracts, alone or in combination with methotrexate (MTX). Possible apoptosis was investigated using Annexin-V/PI double staining. Real-time PCR was applied to evaluate the expression levels of related ABC transporters upon combination therapy. RESULTS: The IC50s for cinnamon, ginger and green tea extracts on ALL cell lines were 300 µg/ml, 167 µg/ml and 70 µg/ml, respectively. Surprisingly, the methotrexate (MTX)-resistant sub-line showed more sensitivity to ginger. Combined treatment with ginger and MTX showed synergistic effects on CCRF-CEM, Nalm-6 and ALL primary cells. It was shown that ginger does not impair the high expression levels of ABCA2 or ABCA3 transporter genes in the ALL malignant cells, suggesting other molecular pathways involved in its anticancer potential. CONCLUSION: To the best of our knowledge, this is the first study that reveals the antileukemic effect of ginger extract on both, pediatric ALL cell lines and primary cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Gengibre/química , Extratos Vegetais/farmacologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Antineoplásicos Fitogênicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Pré-Escolar , Cinnamomum zeylanicum/química , Terapia Combinada , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Masculino , Metotrexato/administração & dosagem , Fitoterapia , Extratos Vegetais/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Chá/química , Células Tumorais Cultivadas , Adulto Jovem
14.
Chemosphere ; 232: 281-286, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31154189

RESUMO

The environmental persistence of hazardous organochlorine pesticides (OCPs) such as lindane has resulted in a need for the development of reliable remediation technology for the removal of OCPs. Green tea extract/Fe2+ under alkaline conditions is a potential green chemistry technology proven to be effective in reducing lindane. This study investigated the feasibility of directly using green tea leaves (GT-leaf) or cold-brew tea solution (GT-sol) with Fe2+ additives at (bi)carbonate buffered pH 10 to treat lindane in the aqueous phase. The polyphenol was gradually released in the GT-leaf system and reached a similar concentration as that in the GT-sol system (∼800 mg L-1 at pH 6.5). Based on the analytical results of lindane degradation byproducts, it was recognized that the reductive mechanism acts as a major pathway and alkaline hydrolysis is a minor pathway. However, physical adsorption rapidly removes lindane from the GT-leaf system. A comprehensive evaluation of lindane degradation, chlorobenzene formation, degradation kinetics, and chloride liberation were conducted for the alkaline GT-sol/Fe2+ system. The nonlinear simulations of the models developed showed good fits, with R2 > 0.96. This study highlights the potential for GT-sol/Fe2+ systems to remediate OCPs contamination.


Assuntos
Hexaclorocicloexano/química , Chá/química , Adsorção , Poluentes Ambientais , Hexaclorocicloexano/análise , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/química , Cinética , Praguicidas/análise , Praguicidas/química , Folhas de Planta/química
15.
Food Chem ; 293: 271-277, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151611

RESUMO

The contamination of pesticide residues in Oolong tea has raised much concern in recent years. The objective of this study was to synthesize gold nanoparticles (AuNPs) and develop surface-enhanced Raman spectroscopy (SERS) methods for detection and quantification of pesticides in Oolong tea. Facile synthesis of spherical and monodispersed AuNPs with an average diameter of 15 nm was achieved, which induced strong electromagnetic fields in SERS analysis. AuNP substrates were employed for rapid detection and quantification of carbendazim in Tieguanyin Oolong tea. Partial least squares (PLS) analysis and leave-one-out cross validation were utilized in spectral data analysis. The PLS results for Oolong tea samples were obtained: R value = 0.964; the detection limit = 100 µg/kg. These results demonstrate that SERS coupled with gold nanoparticle substrate is a simple, rapid, and sensitive analytical tool for measurement and quantification of carbendazim residues in Oolong tea.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Ouro/química , Nanopartículas Metálicas/química , Resíduos de Praguicidas/análise , Praguicidas/análise , Análise Espectral Raman/métodos , Chá/química , Cor , Limite de Detecção
16.
Food Chem Toxicol ; 131: 110551, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31163217

RESUMO

Tea is a natural resource of catechins and exhibits antioxidative and anticancer activities. This study was designed to elucidate the comparative efficacy of white tea and pure EGCG in containing benzo (a) pyrene (BaP)-induced pulmonary stress. Rats were treated with white tea extract (WT) (1%) and pure EGCG at a dose of 80µg/ml in drinking water on alternate days for 12 weeks (4 weeks prior, during and after BaP treatment). BaP(50 mg/kg b. wt) was administered to rats orally in olive oil twice a week for four weeks. The indices such as stress biomarkers (LPO, PCC & ROS), antioxidant enzymes (SOD, CAT, GSH, GST, GR, GPx) activities and lung histoarchitecture were assessed. BaP administration enhanced the levels of inflammatory markers (NO and citrulline) and reduced activities of antioxidant enzymes. We observed similar antioxidant efficacy by both WT and EGCG as seen by their ameliorative action in restoring BaP induced oxidative and inflammatory stress as well as lung histoarchitecture. Our findings suggest that WT is equally beneficial as EGCG in maintaining the integrity of alveoli and is a potential candidate to be used as a cost effective and protective agent in conditions of BaP-induced lung damage.


Assuntos
Benzo(a)pireno/toxicidade , Catequina/análogos & derivados , Depuradores de Radicais Livres/uso terapêutico , Lesão Pulmonar/prevenção & controle , Extratos Vegetais/uso terapêutico , Chá/química , Animais , Biomarcadores/metabolismo , Camellia sinensis/química , Catequina/uso terapêutico , Citrulina/metabolismo , Feminino , Inflamação/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/patologia , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Carbonilação Proteica/efeitos dos fármacos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
17.
Food Chem ; 297: 124992, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253327

RESUMO

Complex starch is gaining research attention due to its unique physicochemical and functional properties. In this study, the effects of green tea polyphenols on the properties and digestion of lotus seed starch under high hydrostatic pressure were investigated. The particle size, swelling power, solubility, crystallization, morphology and thermal properties of lotus seed starch were affected by green tea polyphenols. These may be due to the formation of non-inclusive complexes between lotus seed starch and green tea polyphenols. The morphology and green tea polyphenols distribution of the complexes were determined by scanning electron microscopy and confocal laser scanning microscopy. In addition, slow digestion properties of starch were realized under a dynamic in vitro rat stomach-duodenum model and the erosion of granules by amylase gradually decreased by scanning electron microscopy. Furthermore, green tea polyphenols were shown to be able to form V-type inclusion complex with amylose via high hydrostatic pressure.


Assuntos
Lotus/metabolismo , Polifenóis/química , Amido/química , Chá/química , Animais , Varredura Diferencial de Calorimetria , Cristalização , Pressão Hidrostática , Lotus/química , Modelos Biológicos , Tamanho da Partícula , Ratos , Sementes/química , Sementes/metabolismo , Solubilidade , Amido/metabolismo , Chá/metabolismo
18.
Fitoterapia ; 137: 104240, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31201887

RESUMO

Anhua dark tea known as the earliest produced Chinese dark tea, has been commercially available and famous for its unique flavor and health care effect. NMDA receptors are glutamate-coupled ion channels that critically involved in survival of neuronal cells and neurodegenerative diseases. Thus, it is considered a promising target for the therapy of neurodegenerative disease. In this study, four catechins including two new catechins derivatives (1-2), together with thirteen known flavonoids were isolated from Anhua dark tea. The structures of compounds 1-2 [2S,3R-6-methoxycarbonylgallocatechin (1) and 2R,3R-6-methoxycarbonylgallocatechin (2)] were determined on the basis of their spectroscopic data. The preliminary bioassay indicated that compound 1 showed the best neuroprotective effects via N-methyl-d-aspartate (NMDA) receptors inhibition. Compound 1 protected SH-SY5Y cells against NMDA-induced injury and cell apoptosis via the modulation of NR2B expression, the activation of PI3K/Akt signaling and caspase-dependent pathway. The results suggested compound 1 would be a potent dietary therapy reagent for prevention of excitable brain injury.


Assuntos
Catequina/farmacologia , Flavonoides/farmacologia , Fármacos Neuroprotetores/farmacologia , Chá/química , Apoptose , Catequina/análogos & derivados , Linhagem Celular Tumoral , Flavonoides/isolamento & purificação , Humanos , Estrutura Molecular , Neuroblastoma , Fármacos Neuroprotetores/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
19.
J Agric Food Chem ; 67(25): 7128-7135, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31150244

RESUMO

Tea polyphenols lower the levels of cholesterol in the blood by decreasing the cholesterol micellar solubility. To clarify this mechanism, the interactions between taurocholic acid and (-)-epigallocatechin gallate (EGCg) and its derivatives were investigated. 13C NMR studies revealed remarkable chemical-shift changes for the carbonyl carbon atom and the 1″- and 4″-positions in the galloyl moiety. Furthermore, 1H NMR studies using (-)-EGCg derivatives showed that the number of hydroxyl groups on the B ring did not affect these interactions, whereas the carbonyl carbon atom and the aromatic ring of the galloyl moiety had remarkable effects. The configuration at the 2- and 3-positions of the catechin also influenced these interactions, with the trans-configuration resulting in stronger inhibition activity than the cis-configuration. Additionally, a 1:1 component ratio for the catechin-taurocholic acid complex was determined by electrospray ionization-mass spectrometry. These molecular mechanisms contribute to the development of cholesterol-absorption inhibitors.


Assuntos
Anticolesterolemiantes/química , Camellia sinensis/química , Catequina/química , Colesterol/química , Chá/química , Humanos , Espectroscopia de Ressonância Magnética , Micelas , Estrutura Molecular , Solubilidade , Espectrometria de Massas por Ionização por Electrospray
20.
Molecules ; 24(9)2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31052526

RESUMO

An aroma-based method for distinguishing different grades of Nongxiang Tieguanyin was explored by taking special grade (K110) and 1-4 grades (K101, K102, K103, and K104) of this tea as samples. Tea samples were analyzed by gas chromatography-mass spectrometry (GC-MS) combined with chemometrics. Results showed differences in the types and relative contents of aroma components among different grades of Nongxiang Tieguanyin tea. In the principal component analysis (PCA) scoring plot, except for K102 and K103, tea samples of different grades were distributed in different regions. Components satisfying variable important for the projection (VIP) > 1 and peak areas with significant differences (p < 0.05) among different tea grades were screened. Finally, 18 differential variables were screened out from 143 volatiles. The clustering results of these variables were consistent with those of PCA. K102 and K103 were initially clustered into one group and then clustered with K101, K110, and K104 in turn. The clear PCA separation of these samples and uniform hierarchical cluster analysis (HCA) clustering results suggests that GC-MS coupled with chemometrics analysis is a valid and accurate approach for discriminating different grades of Nongxiang Tieguanyin. The screened differential variables could represent a difference in aroma quality among five grades of Nongxiang Tieguanyin tea. Clear rules between peak area and the grade were also observed in some differential variables. 1-Ethylpyrrole and unknown-32 were positively correlated with grade. 2-Methylfuran, 2-ethylfuran, 2-methylidenecyclopentan-1-ol, mesityl oxide, 2-amylfuran, and D-limonene were negatively correlated with grade. The peak areas of methyl acetate, dimethyl sulfide, 6-methylhept-5-en-2-one, and (Z)-ß-ocimene initially decreased but then increased with declining grade. The toluene content was especially high in K104 but only a negligible difference was observed among other grades. This study provides a potential method for differentiating Nongxiang Tieguanyin teas of different grades based on aroma. Unknown samples could be classified by comparison of their spatial distribution with those of known standard samples in PCA or HCA, as well as the peak area differences of differential variables between unknown samples and known standard samples.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Odorantes/análise , Compostos Fitoquímicos/análise , Chá/química , Chá/classificação , Análise de Variância , Compostos Fitoquímicos/química , Chá/normas , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
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