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1.
J Agric Food Chem ; 68(8): 2381-2392, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32037817

RESUMO

Increasing level of inflammation and oxidative stress could lead to memory impairment. The purpose of this study was to determine the neuroprotective effects of walnut peptides against memory deficits induced by lipopolysaccharide (LPS) in mice and further to explore the underlying anti-inflammatory mechanisms against LPS-elicited inflammation in BV-2 cells. Results showed that walnut protein hydrolysate (WPH) and its low-molecular-weight fraction (WPHL) could ameliorate the memory deficits induced by LPS via normalizing the inflammatory response and oxidative stress in brain, especially WPHL. Furthermore, 18 peptides with anti-inflammatory activities on LPS-activated BV-2 cells were identified from WPHL and it was found that Trp, Gly, and Leu residues in peptides might contribute to the anti-inflammation. Meanwhile, the strong anti-inflammatory effects of LPF, GVYY, and APTLW might be related to their hydrophobic and aromatic amino acid residues as well. LPF, GVYY, and APTLW could reduce the content of proinflammatory mediators and cytokines by downregulating related enzyme expressions and mRNA expressions. Additionally, ROS and mitochondria homeostasis might also contribute to their anti-inflammatory effects.


Assuntos
Anti-Inflamatórios/administração & dosagem , Disfunção Cognitiva/tratamento farmacológico , Juglans/química , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/administração & dosagem , Animais , Anti-Inflamatórios/química , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/imunologia , Disfunção Cognitiva/psicologia , Humanos , Lipopolissacarídeos/efeitos adversos , Aprendizagem em Labirinto , Camundongos , Peso Molecular , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/química , Nozes/química , Peptídeos/química
2.
J Agric Food Chem ; 68(8): 2393-2405, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31995979

RESUMO

Hyperglycemia-induced oxidative stress can cause liver damage in diabetes, and protein hydrolysates with antidiabetic and antioxidant properties are emerging as a potential therapy. In this study, protective effects of casein hydrolysates against live oxidative damage in streptozotocin/high-fat-induced diabetic rats were studied and potentially bioactive peptides were explored by an integrated approach of differential peptide and in silico analysis. Results showed that different casein hydrolysates significantly alleviated liver oxidative damage (p < 0.05) via different mechanisms. Particularly, casein hydrolyzed by a papain-flavourzyme combination (P-FCH) treatment significantly improved liver antioxidant enzyme activities by enhancing nuclear factor erythroid 2-related factor 2 (Nrf2) transcription (p < 0.05). Furthermore, 18 peptides were screened as potential bioactive peptides by analyzing differential peptides among different hydrolysates combined with in silico prediction. Among them, the dipeptide WM might directly inhibit the Kelch-like ECH-associated protein 1 (Keap1)-Nrf2 interaction as potential Nrf2 activators. These results suggested that P-FCH might be an alternative way to treat liver damage in diabetes.


Assuntos
Caseínas/química , Diabetes Mellitus Experimental/tratamento farmacológico , Hepatopatias/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/administração & dosagem , Animais , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Dieta Hiperlipídica/efeitos adversos , Feminino , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Hepatopatias/genética , Hepatopatias/metabolismo , Masculino , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Peptídeos/química , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
3.
J Agric Food Chem ; 67(50): 13978-13985, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31757126

RESUMO

Protein oxidation results in structural modification which affects its digestion. The objective of this work was to investigate the influence of lipoxygenases (LOX) catalyzed linoleic acid (LA) oxidation on the structure and in vitro gastric digests of soybean protein isolate (SPI). Fluorescence recovery after photobleaching (FRAP) was used to evaluate the relationship between pepsin diffusion and gastric digestion. Results indicated that oxidation induced carbonyl formation and loss of free sulfhydryl. Increased surface hydrophobicity and zeta-potential verified the protein unfolding and thus resulted in a small particle size and low fluorescence intensity. Fourier transform infrared spectroscopy (FTIR) showed that oxidation caused the increases in ß-sheets mostly at the expense of α-helix and random coils. Fluorescein isothiocyanate (FITC)-pepsin in SPI solution modified with 3 mL LA showed a faster diffusion rate with 80.51 µm2/s as well as a higher DH value of 9.11%, showing that pepsin diffusivity might play an important role in protein gastric digestion.


Assuntos
Mucosa Gástrica/metabolismo , Ácido Linoleico/metabolismo , Lipoxigenase/metabolismo , Proteínas de Soja/química , Proteínas de Soja/metabolismo , Digestão , Humanos , Interações Hidrofóbicas e Hidrofílicas , Ácido Linoleico/química , Lipoxigenase/química , Modelos Biológicos , Oxirredução , Pepsina A/química , Pepsina A/metabolismo , Dobramento de Proteína , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Food Funct ; 10(12): 7733-7744, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31691688

RESUMO

Sleep deprivation negatively influences memory formation and consolidation, which leads to memory impairment associated with oxidative stress and neurotrophic pathways. In this study, a sleep-deprived rat model was used to evaluate the protective effects of round scad hydrolysates (RSH, 333 and 666 mg per kg bw) on memory impairment and the underlying mechanisms. The result of the Morris water maze test revealed that RSH significantly reversed the cognition deficits induced by sleep deprivation. Moreover, RSH supplementation alleviated oxidative stress by increasing the activities of glutathione peroxidase and superoxide dismutase and the ratio of glutathione/oxidized glutathione in the brain. Furthermore, RSH significantly up-regulated the expression of antioxidant defense-related proteins, including nuclear factor E2-related factor 2 (Nrf2) and its downstream heme oxygenase-1 (HO-1), as well as the phosphorylation of Akt in rats. Moreover, RSH improved the expression of brain-derived neurotrophic factor (BDNF), the phosphorylation of cAMP response element-binding (CREB) and tropomyosin-related kinase B (TrkB) in vivo, indicating that RSH can also promote the expression of proteins related to the neurotrophic pathway. Additionally, UPLC-qTOF-MS/MS was further used to identify the peptides in RSH. The results indicated that RSH mainly consists of low molecular weight peptides with hydrophobic, aromatic and positively charged amino acids in sequence. Taken together, these findings demonstrate that RSH exerts memory-improving actions by regulating the antioxidant and neurotrophic pathways, and RSH can be a potential functional ingredient for the prevention and protection of cognitive deficits.

5.
J Chromatogr A ; 1602: 273-283, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31182307

RESUMO

In this work, an improved algorithm was developed for two-dimensional (2D) peak detection in complex two-dimensional liquid chromatography (LC×LC) data sets. In the first step, conventional one-dimensional peak detection was performed. In the second step, retention time, bidirectional overlap and unimodality criteria were applied to decide which of the individual peaks should be merged. To improve the peak detection with LC×LC analysis using shifting second dimension (2D) gradients, the variable thresholds, which permitted different thresholds for candidate peaks at different first dimension (1D) retention times, were employed for examination of the 2D retention time differences. Furthermore, the bidirectional overlap criterion performed at specified height was recommended to improve detection for tailing peaks. The developed algorithm was further tested on data sets from different LC×LC analyses of a complex peptide mixture, and then quantitatively evaluated by comparison between the results by the algorithm and mass analysis. Evidently improved performance with an accuracy rate over 60% was obtained by the algorithm, even for peak detection with LC×LC analysis under relatively low 1D sampling frequency or shifting 2D gradients. This would help to improve LC×LC quantitative analysis and performance assessment.


Assuntos
Algoritmos , Cromatografia Líquida/métodos , Análise de Dados , Análise por Conglomerados
6.
Food Chem ; 295: 120-128, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174740

RESUMO

This research investigated the effects of commonly practiced thermal treatments (simulated pasteurization, retort sterilization and UHT sterilization) on peanut protein isolate (PPI)-glucose solution. Results showed that thermal treatment on PPI-glucose solution from mild to drastic conditions would lead to a more ordered and compact protein structure, greater extent of Maillard reaction, higher degree of graft, stronger in vitro antioxidant activities, but decrease in vitro digestion especially lower degree of hydrolysis in two-step enzymolysis by pepsin and then pancreatin. Compared with the unheated PPI-glucose solution, the Td values of ones autoclaved at 121 °C for 30 min and 45 min increased by 5% and 12%, and the ΔH of all the heated samples was lower than the unheated one. The present study indicated that retort sterilization or UHT sterilization treatment could be favourable in producing a beverage containing PPI and glucose with proper digestibility and post-digestion antioxidant activities.


Assuntos
Arachis/metabolismo , Glucose/química , Proteínas de Plantas/metabolismo , Antioxidantes/química , Varredura Diferencial de Calorimetria , Dicroísmo Circular , Hidrólise , Reação de Maillard , Pasteurização , Pepsina A/metabolismo , Proteínas de Plantas/química , Estrutura Terciária de Proteína , Temperatura
7.
Food Funct ; 10(5): 2439-2449, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-30968880

RESUMO

The peptide derived from Anchovy hydrolysates, Pro-Ala-Tyr-Cys-Ser (PAYCS), was reported to display a neuroprotective effect in vitro in our previous study. The in vivo memory improving effects of PAYCS were investigated in this study. Prior to the scopolamine-induced amnesia mice trial, the stability of PAYCS during digestion was detected and the digestive products were identified. The results showed that PAYCS was susceptible to proteolytic degradation after incubation with pepsin and pancreatin and Pro-Ala-Tyr (PAY) was released and survived during the simulated GI digestion. The results of scopolamine-induced amnesia model trials showed that PAYCS and PAY treatment exhibited cognitive improvement effects in the behavioral tests and different pathways were determined. The results indicated that only PAYCS facilitated cholinergic activity by up-regulating the amount of acetylcholine (Ach) and acetylcholine receptor (AChR). Additionally, both PAYCS and PAY enhanced the superoxide dismutase (SOD) activity. Furthermore, PAYCS was found to be beneficial for the expression of the nuclear factor (erythroid-derived2)-like 2 protein (Nrf2), brain-derived neurotrophic factor (BDNF) and cAMP response element binding protein (CREB). This indicated that PAYCS could regulate the oxidative stress by activating the Nrf2/antioxidant response elements (Nrf2/ARE) pathway. In our study, we demonstrated that the memory improving effects conferred by PAYCS on amnesia mice were linked to the attenuation of the cholinergic system and the activation of Nrf2/ARE and BDNF/CREB signaling.


Assuntos
Amnésia/tratamento farmacológico , Amnésia/psicologia , Proteínas de Peixes/química , Trato Gastrointestinal/metabolismo , Peptídeos/administração & dosagem , Peptídeos/química , Acetilcolina/metabolismo , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Amnésia/etiologia , Amnésia/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cognição/efeitos dos fármacos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Feminino , Peixes , Humanos , Masculino , Memória/efeitos dos fármacos , Camundongos , Fármacos Neuroprotetores/administração & dosagem , Peptídeos/metabolismo , Escopolamina/efeitos adversos
8.
Food Res Int ; 120: 178-187, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31000228

RESUMO

The antioxidant and aphrodisiac properties of oyster meat (OM) and its hydrolysates by alcalase (OMA) were compared. The results showed that OMA displayed a higher antioxidant activity than OM with or without gastrointestinal digestion. Furthermore, the study reported that oral administration of OM or OMA could induce aphrodisiac activities and consequently enhance the sexual behavior in normal male mice, at a dose of 250 mg/kg. Additionally, OMA also exhibited better antioxidant activity in vivo than OM by improving the activities of the endogenous cellular antioxidant enzymes and decreasing the MDA levels, which may be helpful in improving the sexual function. These results indicated that oysters' could be a potential functional ingredient with antioxidant and aphrodisiac activities, and the activities could be improved by alcalase hydrolysis.

9.
Food Res Int ; 120: 895-903, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31000311

RESUMO

This study aimed to examine the feasibility of improving umami taste of peanut protein isolate hydrolysate (PPIH) and its fractions (obtained via ethanol precipitation and gel filtration chromatography) and peptide constituents, through their reactions with glucose at 98 °C for 70 min (Maillard reaction). To get insights into the characteristics of the peptide contributors with high umami intensity and/or umami-enhancing activity, Maillard reaction-guided and sensory-guided fractionation and characterization using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and eXpose algorithm calculation method were subsequently involved. Three umami and umami-enhancing peptides, three umami-enhancing peptides with other tastes, three bitter peptides and one astringent peptide were found. For the first time, peptide TP was reported to suppress umami intensity of monosodium glutamate (MSG) aqueous solution. Combined treatments of enzymatic hydrolysis and Maillard reaction on PPI facilitated umami enhancement. Maillard products of identified peptides had higher umami intensities and/or greater umami-enhancing abilities. Pyroglutamylproline (pyroEP) and glucosylated EP were discovered as the major compounds of EP Maillard product.

10.
Food Chem ; 272: 453-461, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30309568

RESUMO

This study follows recent attempts to discover natural xanthine oxidase (XO) inhibitors from foods, focusing herein on under-researched fish proteins. The anti-hyperuricemic function of tuna flesh hydrolysate (TPH) produced using Alcalase 2.4L was confirmed in potassium oxonate-induced hyperuricemic rats. TPH was separated using 80 wt% aqueous ethanol. The ethanol-soluble fraction (ESF) abundant in small peptides (<1000 Da) afforded the highest XO inhibition. Separation of ESF by Sephadex G-15 and UPLC/MS/MS revealed 13 di-/tri-peptides (12 are newly identified XO inhibitors). Their XO inhibitory activities were assessed using corresponding synthetic peptides via an improved HPLC method. Results indicate that Phe-containing peptides were more potent XO inhibitors than Trp-containing peptides, with Phe-His having the highest XO inhibitory activity (IC50 = 25.7 mM). Molecular docking studies revealed the importance of two hydrogen bonds and one π-π stacking interaction with Phe-914 in XO for XO-peptide inhibitor binding. Phe-containing di-/tri-peptides could be potent XO inhibitors against hyperuricemia.


Assuntos
Inibidores Enzimáticos/uso terapêutico , Hiperuricemia/tratamento farmacológico , Hidrolisados de Proteína/metabolismo , Atum/metabolismo , Xantina Oxidase/antagonistas & inibidores , Animais , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Inibidores Enzimáticos/metabolismo , Etanol/química , Ligação de Hidrogênio , Hiperuricemia/induzido quimicamente , Hiperuricemia/veterinária , Simulação de Acoplamento Molecular , Ácido Oxônico/toxicidade , Peptídeos/análise , Peptídeos/uso terapêutico , Hidrolisados de Proteína/isolamento & purificação , Estrutura Terciária de Proteína , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem , Xantina Oxidase/metabolismo
11.
Food Chem ; 278: 674-682, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-30583429

RESUMO

Six novel peptides were separated from peanut protein isolate hydrolysate (PPIH) using ethanol precipitation and gel chromatography, and identified as DQR, NNP, EGF, EDG, TESSSE and RGENESEEEGAIVT by UPLC-ESI-QTOF-MS/MS. On the basis of sensory results, all peptides were perceived umami with threshold values from 0.39 to 1.11 mM and had umami-enhancing abilities simultaneously with threshold values from 0.33 to 0.82 mM. RGENESEEEGAIVT was the first discovered tetradecapeptide with umami and umami-enhancing ability. The dose-response test revealed that umami-enhancing activities of identified peptides were different: TESSSE and RGENESEEEGAIVT imparted better umami intensity when equimolar monosodium glutamate (MSG) was added into 0.5 g/L MSG solution. Taste profile analyses of complex mixtures with/without synthetic peptides were determined by both electronic tongue and human panellists, suggesting that umami peptides influence multiple tastes and electronic tongue has the potential to replace sensory test to distinguish taste attributes of foods rich in peptides.


Assuntos
Arachis/metabolismo , Oligopeptídeos/química , Proteínas de Plantas/metabolismo , Paladar/fisiologia , Sequência de Aminoácidos , Precipitação Química , Cromatografia Líquida de Alta Pressão , Nariz Eletrônico , Humanos , Oligopeptídeos/isolamento & purificação , Hidrolisados de Proteína/metabolismo , Glutamato de Sódio/química , Espectrometria de Massas por Ionização por Electrospray
12.
J Agric Food Chem ; 66(41): 10760-10768, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30269487

RESUMO

This study aimed to investigate the protective effects of bovine elastin hydrolysates on UV-induced skin photoaging in mice and to identify the potent antiphotoaging peptides. Results showed that the ingestion of elastin peptides could obviously ameliorate epidermis hyperplasia and fibroblast apoptosis, and increase the content of hydroxyproline and water in photoaging skin in vivo ( p < 0.05). Furthermore, four peptides with elastase inhibitory activity were purified and identified, including GLPY, PY, GLGPGVG, and GPGGVGAL. Interestingly, GLPY and GPGGVGAL exhibited the highest inhibition activity with 58.77% and 42.91% at 10 mΜ, respectively. This might be attributed to the N-terminal Gly, C-terminal Leu, and Pro at the third position of the N-terminus, which showed stronger affinity and interaction with elastase. Moreover, GLPY and GPGGVGAL could also inhibit the apoptosis of fibroblasts effectively at 50 µΜ ( p < 0.01). It suggested that elastin peptides had great potential to prevent and regulate skin photoaging.


Assuntos
Antioxidantes/química , Elastina/química , Peptídeos/química , Dermatopatias/prevenção & controle , Raios Ultravioleta , Sequência de Aminoácidos , Aminoácidos/química , Animais , Antioxidantes/uso terapêutico , Sítios de Ligação , Bovinos , Linhagem Celular , Sobrevivência Celular , Elastina/isolamento & purificação , Elastina/metabolismo , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Camundongos , Simulação de Acoplamento Molecular , Peptídeos/metabolismo , Ligação Proteica , Conformação Proteica , Espécies Reativas de Oxigênio/metabolismo , Pele , Envelhecimento da Pele , Dermatopatias/metabolismo
13.
J Agric Food Chem ; 66(40): 10617-10627, 2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30226056

RESUMO

The aim of this study was to determine the neuroprotective effects of walnut protein hydrolysates (WPH) against memory deficits induced by sleep deprivation (SD) in rat and further to identify and characterize the potent neuroprotective peptides against glutamate-induced apoptosis in PC12 cells. Results showed that a remarkable amelioration effect on behavioral performance in Morris water maze test was observed for WPH and its low molecular weight fraction WPHL, especially for WPHL. Additionally, a reduction of antioxidant defense (catalase, glutathione peroxidase (GSH-px), and superoxide dismutase (SOD)) and an increase of malondialdehyde content induced by SD were normalized in brain of rat after oral administration of WPH and WPHL. Then three neuroprotective peptides including GGW, VYY, and LLPF were identified from WPHL, which could protect PC12 cells against glutamate-induced apoptosis with relative cell viability of 78.29 ± 3.09%, 80.65 ± 1.74%, and 83.97 ± 3.06%, respectively, versus glutamate group 48.61 ± 3.99%. The possible mechanism underlying their protective effects of GGW and VYY could be related to their strong radical scavenging activity as well as their ability to reduce reactive oxygen species production and the depletion of SOD and GSH-px in PC12 cells. Notably, the marked neuroprotective effects of LLPF, which did not show obvious free-radical scavenging activity in vitro, could be attributed to its strong effects on inhibiting Ca2+ influx and mitochondrial membrane potential collapse. Additionally, all these peptides could regulate the expression of apoptosis-related proteins (Bax and Bcl-2). Therefore, walnut peptides might be regarded as the potential nutraceuticals against neurodegenerative disorders associated with memory deficits.


Assuntos
Juglans/química , Memória/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/administração & dosagem , Privação do Sono/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Catalase/metabolismo , Feminino , Glutationa Peroxidase/metabolismo , Humanos , Masculino , Malondialdeído/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Fármacos Neuroprotetores/química , Células PC12 , Peptídeos/química , Ratos , Espécies Reativas de Oxigênio/metabolismo , Privação do Sono/metabolismo , Privação do Sono/fisiopatologia , Privação do Sono/psicologia , Superóxido Dismutase/metabolismo
14.
Anal Chim Acta ; 1018: 119-126, 2018 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-29605129

RESUMO

Size-exclusion chromatography (SEC) with wide application in peptide analysis presents challenges in determination of molecular weight distribution due to the relatively low resolution. In this study, a stop-flow reversed phase liquid chromatography (RPLC) × SEC system was constructed, aiming at improving the peptide separation in SEC. As the chromatographic dispersion during stop-flow operation might contribute to the band broadening in the first dimension (1st D) RPLC, the effects of different stop-flow operational parameters on the additional band broadening were quantitatively evaluated. Unlike analytes of large molecular size or long retention time with low effective diffusion coefficient (Deff), additional band broadening was evidently observed for analytes of small molecular size and short retention time (high Deff). Therefore, optimal flow rate, low column temperature and short stop-flow time were suggested for analyzing small molecules of short retention time. The established stop-flow two-dimensional liquid chromatography (2D-LC) was further tested on protein hydrolysates. The resolution was evidently improved for both heart-cutting and comprehensive 2D-LC analysis (despite additional band broadening in RPLC). Compared with heart-cutting analysis with higher 1st D resolution for selective fractions, comprehensive analysis could provide more complete information about the molecular weight distribution of the eluting solutes along RPLC.


Assuntos
Cromatografia em Gel , Cromatografia de Fase Reversa , Peptídeos/isolamento & purificação , Cromatografia em Gel/instrumentação , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia de Fase Reversa/instrumentação , Peptídeos/química
15.
Food Res Int ; 105: 556-562, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29433247

RESUMO

This study systematically explored the effect of HEPES, Tris and sodium phosphate (PB) buffers on the xanthine oxidase (XO) inhibitory activity of tuna protein hydrolysate (TPH, containing over 90% of constituents with molecular weight below 5kDa). The greatest XO inhibition by TPH was observed in HEPES buffer. The optimal HEPES concentration was 100mmol/L. Tryptophan fluorescence and circular dichroism measurements revealed the comparable stability of XO and TPH in the three buffers. The buffers did not alter the majority of XO or TPH structure but induced slight modifications to specific domains (e.g. Trp residues on α-helices) and certain rearrangements (e.g. XO unfolding or refolding). HEPES buffer exerted stronger interactions with XO or TPH, causing a lower α-helical content in XO and consequently a lower XO catalytic activity but greater XO inhibition, compared to Tris and PB buffers.


Assuntos
Inibidores Enzimáticos/farmacologia , Proteínas de Peixes da Dieta/farmacologia , Manipulação de Alimentos/métodos , HEPES/química , Fosfatos/química , Hidrolisados de Proteína/farmacologia , Alimentos Marinhos , Trometamina/química , Atum , Xantina Oxidase/antagonistas & inibidores , Animais , Tampões (Química) , Dicroísmo Circular , Inibidores Enzimáticos/isolamento & purificação , Estabilidade Enzimática , Proteínas de Peixes da Dieta/isolamento & purificação , Concentração de Íons de Hidrogênio , Dobramento de Proteína , Hidrolisados de Proteína/isolamento & purificação , Estrutura Secundária de Proteína , Espectrometria de Fluorescência , Relação Estrutura-Atividade , Xantina Oxidase/química , Xantina Oxidase/metabolismo
16.
Food Funct ; 9(2): 774-784, 2018 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-29309081

RESUMO

In this study, the ameliorative effect of chicken breast muscle hydrolysates (CBMHs) against acute alcohol-induced liver injury was investigated and its probable mechanism was further elucidated. In vitro studies clearly showed that CBMHs are able to activate alcohol metabolic enzymes (i.e. alcohol dehydrogenase, ADH) in an exponential manner. Meanwhile, an in vivo experiment on male NIH mice indicated that the oral administration of CBMHs (150, 300 and 600 mg per kg bw) 30 min prior to acute alcohol ingestion could significantly promote alcohol metabolism as revealed by the reduced duration of the loss of righting reflex (LORR) and the enhanced activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in the liver, the latter accelerating alcohol oxidation and therefore the decreased blood alcohol concentration (BAC) level. Pretreatment with CBMHs significantly decreased the elevations of serum aspartate transaminase (AST) and alanine transaminase (ALT) after alcohol administration. CBMHs could also retard lipid peroxidation as revealed by the suppressed malondialdehyde (MDA) level and simultaneously enhance the activities of superoxide dismutase (SOD) in liver tissue. Furthermore, increased histological damage and higher (p < 0.05) hepatic triglyceride (TG) contents in acute alcoholic-diet fed mice were also reduced (p < 0.05) by supplementing with CBMHs. These benefits clearly suggested that CBMHs could be a potential nutraceutical to facilitate alcohol metabolism and prevent or ameliorate early liver injury induced by acute alcohol exposure.


Assuntos
Álcool Desidrogenase/metabolismo , Álcoois/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Músculos/química , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/administração & dosagem , Doença Aguda/terapia , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Galinhas , Humanos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Peptídeos/química , Hidrolisados de Proteína/administração & dosagem , Hidrolisados de Proteína/química , Superóxido Dismutase/metabolismo
17.
J Agric Food Chem ; 65(51): 11192-11201, 2017 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-29190426

RESUMO

Ameliorations of cholinergic system dysfunction and oxidative stress in neurodegenerative diseases were main approaches to improve memory disorder. Our previous investigation showed that anchovy protein hydrolysate (APH) could attenuate scopolamine-induced memory deficits in mice by regulating acetylcholinesterase (AChE) activity. Therefore, peptides with AChE inhibitory activity in APH were explored and identified in this study, and their possible neuroprotective mechanisms on glutamate induced apoptosis in PC12 were also elucidated. Two peptides with strong AChE inhibitory capacity were identified as Pro-Ala-Tyr-Cys-Ser (PAYCS) and Cys-Val-Gly-Ser-Tyr (CVGSY) by ultraperformance liquid chromatography coupled with tandem mass spectrometry. The AChE inhibitory was 23.68 ± 0.97% and 6.08 ± 0.41%, respectively. Treatment with PAYCS and CVGSY could significantly (p < 0.05) increase cells viability, reduce lactate dehydrogenase release, reactive oxygen species (ROS) production, malondialdehyde content, and the ratio of Bax/Bcl-2 of glutamate-induced apoptosis PC12 cells (82.78 ± 6.58 and 109.94 ± 7.16% of control, respectively) as well as increase superoxide dismutase and GSH-px activities. In addition, both the peptides could inhibit Ca2+ influx but have no effects on mitochondrial membrane potential. Results indicated that AChE inhibitory peptides (PAYCS and CVGSY) possibly protected the PC12 cells against glutamate-induced apoptosis via inhibiting ROS production and Ca2+ influx. PAYCS and CVGSY might be considered as nutraceuticals for alleviating memory deficits.


Assuntos
Inibidores da Colinesterase/farmacologia , Proteínas de Peixes/química , Ácido Glutâmico/toxicidade , Transtornos da Memória/enzimologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Peptídeos/farmacologia , Acetilcolinesterase/química , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Inibidores da Colinesterase/química , Proteínas de Peixes/farmacologia , Peixes , Glutationa Peroxidase/metabolismo , Humanos , Malondialdeído/metabolismo , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/metabolismo , Transtornos da Memória/fisiopatologia , Neurônios/citologia , Neurônios/enzimologia , Neurônios/metabolismo , Fármacos Neuroprotetores/química , Estresse Oxidativo/efeitos dos fármacos , Células PC12 , Peptídeos/química , Ratos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
18.
J Food Sci Technol ; 54(10): 3102-3110, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28974795

RESUMO

A walnut protein hydrolysate (WPH) was prepared by using a mixture of pancreatin and viscozyme L from industrially available defatted walnut meal. The antioxidant effects of WPH were confirmed and quantified by reducing power, oxygen radical absorbance capacity, hydroxyl radical radical-scavenging activity and ABTS+· radical-scavenging activity assays. The protective effects of WPH on scopolamine-induced learning and memory deficits in mice were also evaluated based on in vivo behavioral tests. Results showed that WPH administration would lead to significantly decreased latencies while increased crossing times and target times in the spatial probe test, and increased escape latency and decreased error times in the step-down avoidance test for the scopolamine-induced dementia mice. Biochemical results indicated that the ameliorative effects of WPH on scopolamine-induced dementia mice could be attributed to the significantly increased amount of acetylcholine receptors. Therefore, WPH may be a potential therapeutic agent against Alzheimer's disease.

19.
J Chromatogr A ; 1521: 80-89, 2017 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-28951053

RESUMO

The need to improve the peak capacity of liquid chromatography motivates the development of two-dimensional analysis systems. This paper presented a fully automated stop-flow two-dimensional liquid chromatography system with size exclusion chromatography followed by reversed phase liquid chromatography (SEC×RPLC) to efficiently separate peptides. The effects of different stop-flow operational parameters (stop-flow time, peak parking position, number of stop-flow periods and column temperature) on band broadening in the first dimension (1st D) SEC column were quantitatively evaluated by using commercial small proteins and peptides. Results showed that the effects of peak parking position and the number of stop-flow periods on band broadening were relatively small. Unlike stop-flow analysis of large molecules with a long running time, additional band broadening was evidently observed for small molecule analytes due to the relatively high effective diffusion coefficient (Deff). Therefore, shorter analysis time and lower 1st D column temperature were suggested for analyzing small molecules. The stop-flow two-dimensional liquid chromatography (2D-LC) system was further tested on peanut peptides and an evidently improved resolution was observed for both stop-flow heart-cutting and comprehensive 2D-LC analysis (in spite of additional band broadening in SEC). The stop-flow SEC×RPLC, especially heart-cutting analysis with shorter analysis time and higher 1st D resolution for selected fractions, offers a promising approach for efficient analysis of complex samples.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Peptídeos/química , Técnicas de Química Analítica/instrumentação , Peptídeos/análise , Peptídeos/isolamento & purificação , Proteínas/análise , Proteínas/química , Proteínas/isolamento & purificação , Reprodutibilidade dos Testes
20.
J Agric Food Chem ; 64(23): 4725-34, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27181598

RESUMO

This is the first report on the ability of soy sauce to effectively reduce the serum uric acid levels and xanthine oxidase (XOD) activities of hyperuricemic rats. Soy sauce was partitioned sequentially into ethyl acetate and water fractions. The ethyl acetate fraction with strong XOD inhibition effect was purified further. On the basis of xanthine oxidase inhibitory (XOI) activity-guided purification, nine compounds including 3,4-dihydroxy ethyl cinnamate, diisobutyl terephthalate, harman, daidzein, flazin, catechol, thymine, genistein, and uracil were obtained. It was the first time that 3,4-dihydroxy ethyl cinnamate and diisobutyl terephthalate had been identified from soy sauce. Flazin with hydroxymethyl furan ketone group at C-1 and carboxyl at C-3 exhibited the strongest XOI activity (IC50 = 0.51 ± 0.05 mM). According to fluorescence quenching and molecular docking experiments, flazin could enter into the catalytic center of XOD to interact with Lys1045, Gln1194, and Arg912 mainly by hydrophobic forces and hydrogen bonds. Flazin, catechol, and genistein not only were potent XOD inhibitors but also held certain antioxidant activities. According to ADME (absorption, distribution, metabolism, and excretion) simulation in silico, flazin had good oral bioavailability in vivo.


Assuntos
Carbolinas/farmacologia , Furanos/farmacologia , Hiperuricemia/dietoterapia , Alimentos de Soja , Ácido Úrico/sangue , Xantina Oxidase/antagonistas & inibidores , Animais , Peso Corporal/efeitos dos fármacos , Carbolinas/farmacocinética , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/farmacologia , Furanos/farmacocinética , Hiperuricemia/induzido quimicamente , Hiperuricemia/tratamento farmacológico , Masculino , Simulação de Acoplamento Molecular , Ácido Oxônico/efeitos adversos , Ratos Sprague-Dawley , Alimentos de Soja/análise , Xantina Oxidase/metabolismo
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