Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Foods ; 12(7)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37048296

RESUMO

To improve the mechanical properties and confer antimicrobial activity, transglutaminase (TGase) was used as a cross-linking agent and lysozyme (LYS) was incorporated as an antimicrobial agent to prepare novel active tilapia collagen (TC) films. While the difference in visual appearance was not obvious, the LYS incorporation increased the opacity of TC films. The water vapor permeability of all TGase cross-linked TC films was significantly (p < 0.05) lower than that of the control film (prepared without TGase and LYS). In addition, while the tensile strength and Young's modulus of all TGase cross-linked TC films were significantly (p < 0.05) higher than those of the control film, elongation at break of all TGase cross-linked TC films was significantly (p < 0.05) lower than that of the control film. LYS incorporated TC films showed antimicrobial activity against E. coli, Staphylococcus aureus, Enterococcus faecium, Bacillus subtilis and Pseudomonas fluorescens. Collectively, TC films with improved physiochemical properties and antimicrobial activity have a good potential to serve as active food packaging materials.

2.
J Food Sci ; 82(10): 2456-2461, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28850664

RESUMO

Cold water extract of P. citrinopileatus (CWEPC) was fractioned into 4 fractions, PC-I (<1 kDa), PC-II (1-3.5 kDa), PC-III (3.5-10 kDa), and PC-IV (>10 kDa), by ultrafiltration. The antioxidant activities, the inhibition of pancreatic α-amylase, intestinal α-glucosidase, and hypertension-linked angiotensin converting enzyme (ACE), as well as the contents of polysaccharides, protein, and phenolic compounds of 4 fractions were determined. The results showed that lower MW fractions exerted a higher antioxidant activity, which was correlated to phenolic contents. The high molecular fraction (PC-IV) exhibited significantly higher inhibitory activity on α-amylase, α-glucosidase, and ACE compared to CWEPC and the other 3 lower MW fractions (<10 kDa), which was more related to protein contents. The inhibition capability of CWEPC and PC-IV on α-amylase activity was 1/13.4 to 1/2.7 relative to that of acarbose, respectively. Kinetic data revealed that PC-IV fraction followed a noncompetitive inhibition pattern on α-glucosidase activity. The study demonstrated that various MW fractions and types of components contribute to different biological functions of P. citrinopileatus and it is protein constituents but not peptides responsible for the hypoglycemic potential of CWEPC.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Anti-Hipertensivos/química , Antioxidantes/química , Hipoglicemiantes/química , Extratos Vegetais/química , Pleurotus/química , Inibidores da Enzima Conversora de Angiotensina/isolamento & purificação , Anti-Hipertensivos/isolamento & purificação , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Humanos , Hipoglicemiantes/isolamento & purificação , Cinética , Peso Molecular , alfa-Amilases Pancreáticas/antagonistas & inibidores , alfa-Amilases Pancreáticas/química , Peptidil Dipeptidase A/química , Extratos Vegetais/isolamento & purificação , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Glucosidases/química
3.
Int J Mol Sci ; 17(10)2016 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-27754362

RESUMO

In our previous work, the ethanolic extract of Panax ginseng C. A. Meyer was successively partitioned using supercritical carbon dioxide at pressures in series to yield residue (R), F1, F2, and F3 fractions. Among them, F3 contained the highest deglycosylated ginsenosides and exerted the strongest antioxidant and anti-inflammatory activities. The aim of this study was to investigate the protective effects of P. ginseng fractions against cellular oxidative stress induced by hydrogen peroxide (H2O2). Viability of adult retinal pigment epithelium-19 (ARPE-19) cells was examined after treatments of different concentrations of fractions followed by exposure to H2O2. Oxidative levels (malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and reactive oxygen species (ROS)) and levels of activity of antioxidant enzymes were assessed. Results showed that F3 could dose-dependently protected ARPE-19 cells against oxidative injury induced by H2O2. F3 at a level of 1 mg/mL could restore the cell death induced by H2O2 of up to 60% and could alleviate the increase in cellular oxidation (MDA, 8-OHdG, and ROS) induced by H2O2. Moreover, F3 could restore the activities of antioxidant enzymes suppressed by H2O2. In conclusion, F3 obtained using supercritical carbon dioxide fractionation could significantly increase the antioxidant capacity of P. ginseng extract. The antioxidant capacity was highly correlated with the concentration of F3.


Assuntos
Antioxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Panax/química , Extratos Vegetais/farmacologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Antioxidantes/química , Dióxido de Carbono/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fracionamento Químico/métodos , Humanos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Extratos Vegetais/química , Espécies Reativas de Oxigênio/metabolismo , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/metabolismo
4.
J Food Drug Anal ; 24(3): 548-555, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-28911560

RESUMO

Extraction temperature can potentially affect the chemical compositions and bioactivities of the extracts obtained. The objective of this study was to investigate the effect of extraction temperature on the distribution of bioactive compounds and the bioactivities of Pleurotus citrinopileatus. The antioxidant activities (2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)+ scavenging capabilities) and the inhibitory capabilities on pancreatic α-amylase, intestinal α-glucosidase, and hypertension-linked angiotensin-converting enzyme of hot water P. citrinopileatus extract and cold water P. citrinopileatus extract were determined. The results showed that the antioxidant capabilities and inhibitory effects on α-amylase, α-glucosidase, and angiotensin-converting enzyme of cold water P. citrinopileatus extract were significantly higher than those of hot water P. citrinopileatus extract. The cold water P. citrinopileatus extracted was further precipitated with 100% ammonium sulfate to obtain a polysaccharide fraction or with 75% ethanol to obtain a protein fraction. The inhibitory activities of the protein fraction of the cold water P. citrinopileatus extract on α-amylase, α-glucosidase, and angiotensin-converting enzyme were significantly higher than those of the polysaccharide fraction. In conclusion, the protein fraction of the cold water P. citrinopileatus extract could be responsible for its bioactivities.


Assuntos
Pleurotus , Inibidores da Enzima Conversora de Angiotensina , Antioxidantes , Carboidratos , Inibidores de Glicosídeo Hidrolases , Fenóis , Extratos Vegetais , Temperatura , alfa-Amilases
5.
Int J Food Sci Nutr ; 65(4): 502-6, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24524622

RESUMO

Viscous dietary fibers were shown to alleviate postprandial blood glucose. Auricularia polytricha (wood ear mushroom, WEM) contains rich amount fibers and water extract WEM was highly viscous. This study aimed to investigate whether WEM extract exhibited hypoglycemic effect in vitro. The effects of WEM extract on glucose adsorption, glucose diffusion, starch digestion and α-amylase activity were examined and compared to those of two high soluble fibers, psyllium and oat fiber and one insoluble fiber, cellulose. Our results showed that WEM extract and psyllium possessed similar ability to adsorb glucose which may thus decrease the level of dialysis glucose. The decrease of dialysis rate is dose-dependent. WEM extract can also suppress the activity of α-amylase which may thus inhibit the digestion of polysaccharides. Since WEM extract exhibited the ability to adsorb glucose and to suppress the activity of α-amylase; it might contribute a beneficial effect on postprandial levels of blood sugar.


Assuntos
Basidiomycota/química , Misturas Complexas/química , Fibras na Dieta/análise , Digestão , Fármacos Gastrointestinais/química , Hipoglicemiantes/química , Modelos Biológicos , Adsorção , Avena/química , Celulose/química , Celulose/metabolismo , Misturas Complexas/metabolismo , Fibras na Dieta/metabolismo , Suplementos Nutricionais , Difusão , Fármacos Gastrointestinais/metabolismo , Glucose/química , Humanos , Hipoglicemiantes/metabolismo , Cinética , Psyllium/química , Psyllium/metabolismo , Solubilidade , Viscosidade , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Amilases/metabolismo
6.
Eur J Appl Physiol ; 111(1): 57-66, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20809228

RESUMO

The aim of this study was to evaluate the acute effect of a single bout of Tai Chi (TC) exercise on adiponectin and glucose homeostasis in individuals with cardiovascular risk factors. Twenty-six individuals (mean age 60.2 years) with at least one cardiovascular risk factor who had been practicing Yang's style TC exercise for at least 3 months were recruited from a regional hospital in Taiwan. A one-group repeated measured quasi-experimental design was used. Participants completed a 60-min Yang's style TC exercise routine including warm up, stretching exercises, and TC followed by a 30-min resting period. After a 1-week washout period, the same group of participants underwent a control condition in which they were instructed to remain seated for 90 min at the study location. Blood samples were collected both before and after the TC intervention or the sitting condition. The difference between pre-post measurements for adiponectin was 0.58 ± 1.42 µg/ml in the TC trial and -0.46 ± 0.99 µg/ml in the sitting trial. The differences between the two trials were statistically significant (P = 0.004). The changes from pretrial to posttrial were significantly greater for glycerol (P < 0.001), cholesterol (P = 0.046), and LDL-C (P = 0.038) in the TC trial compared with those in the sitting trial. Conversely, the changes were significantly lesser for HOMA-IR (P = 0.004), log (HOMA-IR) (P = 0.001), and glucose (P = 0.003) in TC trial compared with those in the sitting trial. In conclusion, a single bout of TC exercise had a significant positive effect on blood adiponectin concentrations in individuals with cardiovascular risk factors.


Assuntos
Adiponectina/sangue , Glicemia/metabolismo , Doenças Cardiovasculares/epidemiologia , Tai Chi Chuan , Adiponectina/metabolismo , Antropometria , Terapia por Exercício , Homeostase/fisiologia , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Taiwan
7.
Food Chem Toxicol ; 45(2): 303-14, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17030378

RESUMO

SC-1, the aqueous phase of soybean fermentation products by bacteria (Bacillus subtilis and Bacillus brevis), significantly inhibited the growth and clonogenesity of human hepatocellular (Hep 3B), mouse hepatocellular (ML-1), and human colorectal (HCT 116 and HT-29) carcinoma cells. Cytotoxicity of SC-1 in Hep 3B cells was through the process of apoptosis characterizing by increase in cell population of sub-G(1) phase, fragmentation of DNA, and change of nuclear morphology. Treatment of Hep 3B cells with SC-1 activated caspase 8 and caspase 3. Elevation of nuclear DNA fragmentation factor 40 (DFF40) and cleavage form of poly(ADP-ribose) polymerase (PARP) were also observed. SC-1 also activated intrinsic pathway via increase of pro-apoptotic (tBid, Bak and Bax) and decrease of anti-apoptotic (Bcl-2 and Bcl-x(L)) proteins on mitochondria, disruption of mitochondrial membrane potential, release of cytochrome c and Smac (second mitochondria-derived activator of caspase/direct IAP binding protein with low PI) from mitochondria, and activation of caspase 9. Inhibition on protein expression of Ku70 in cytosol and cyclooxygenase (COX)-2, but not COX-1, in whole cell lystes were revealed in SC-1-treated Hep 3B cells. These results suggest caspase 8, Ku70 and mitochondria are involved in the antitumor mechanism of SC-1 in Hep 3B cells.


Assuntos
Apoptose/efeitos dos fármacos , Bacillus/metabolismo , Caspase 8/metabolismo , Glycine max/química , Mitocôndrias/metabolismo , Animais , Bacillus subtilis/metabolismo , Carcinoma Hepatocelular/patologia , Caspase 8/efeitos dos fármacos , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/metabolismo , Fragmentação do DNA , Ativação Enzimática , Fermentação , Fase G1/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Neoplasias Hepáticas/patologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo
8.
Food Chem Toxicol ; 43(4): 543-52, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15721201

RESUMO

Supercritical carbon dioxide (SC-CO2) was used as the elution solvent for fractioning ethanolic extract (E) of Cordyceps sinensis (CS), a traditional Chinese herbal remedy, into R, F1, F2, and F3 fractions. This extractive fractionation method is amenable to large scale and is nontoxic. These four fractions were characterized in terms of total polysaccharides and cordycepin concentrations, scavenging ability of free radicals, and anti-tumor activities. Experimental results demonstrated that fractionation altered the distributions of total polysaccharides and cordycepin in fractions. Fraction R was the most active fraction to scavenge free radicals and inhibit the proliferation of carcinoma cells, followed by the fraction F1 and the extract E. The effect of scavenging on 1,1-diphenyl-2-picryl hydrazyl (DPPH) of CS extract and fractions at 2 mg/ml was R (93%), F1 (75%), E (66%), F2 (47%), and F3 (27%). The IC50 (50% cell growth inhibitory concentration) of tumor cell proliferation and colony formation on human colorectal (HT-29 and HCT 116) and hepatocellular (Hep 3B and Hep G2) carcinoma cells by fraction R were around 2 microg/ml. Conversely, R did not affect the growth of normal dividing human peripheral blood mononuclear cells (PBMC) by exhibiting a large value of IC50 over 200 microg/ml. Accumulation of tumor cells at sub-G1 phase and the fragmentation of DNA, typical features of programmed cell death, were observed in a time and dose dependent manner. Scavenging of free radicals and anti-cancer activity (value of IC50) correlated closely with the quantities of polysaccharides (Spearman's rho=0.901 and -0.870, respectively). Taken together, our findings suggest that fraction R, obtained by SC-CO2 fluid extractive fractionation, showed strong scavenging ability and selectively inhibited the growth of colorectal and hepatocellular cancer cells by the process of apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/patologia , Neoplasias do Colo/patologia , Cordyceps/química , Sequestradores de Radicais Livres/farmacologia , Neoplasias Hepáticas/patologia , Dióxido de Carbono/química , Cromatografia com Fluido Supercrítico , DNA/metabolismo , Humanos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Solventes , Células-Tronco , Células Tumorais Cultivadas
9.
Food Chem Toxicol ; 42(4): 609-17, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15019185

RESUMO

Fractionation with supercritical CO(2) is employed to divide ethanolic extract (E) of B. kaoi into four fractions (R, F1, F2 and F3). To assess the selectivity of the fractionation, extracts of the four fractions were characterized in terms of the hepatoprotective capacity and activity of antioxidant enzymes to against CCl(4)-induced damage. The in vitro study revealed that pretreatment with B. kaoi extract or its fractions, except F3, significantly protected primary hepatocytes against damage by CCl(4) (P<0.05). The R and F1 fractions had the highest saikosaponins content (175 and 200 mg/g dry weight, respectively) and most effectively protected the liver from damage by CCl(4). This study demonstrated that the oral pretreatment of B. kaoi (100 and 500 mg/kg), except F3, three days before a single dose of CCl(4) (CCl(4)/olive oil=1:1, 3 ml/kg, sc) was administered significantly lowered the serum levels of hepatic enzyme markers (AST and ALT) (P<0.05). A pathological examination showed that lesions, including ballooning degeneration, necrosis, hepatitis and portal triaditis were partially healed by treatment with B. kaoi extract and fractions. Oxidative stress induced by CCl(4) led to lipid peroxidation (MDA) and changes in the levels of the antioxidant enzymes in the liver. However, all the fractions, except F3, markedly suppressed lipid peroxidation and reversed the activities of the antioxidant enzymes to the normal levels.


Assuntos
Antioxidantes/uso terapêutico , Bupleurum , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Extratos Vegetais/uso terapêutico , Administração Oral , Alanina Transaminase/metabolismo , Animais , Antioxidantes/administração & dosagem , Antioxidantes/análise , Aspartato Aminotransferases/metabolismo , Dióxido de Carbono/química , Tetracloreto de Carbono , Fracionamento Químico , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Relação Dose-Resposta a Droga , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Hepatócitos/patologia , Peroxidação de Lipídeos , Masculino , Extratos Vegetais/administração & dosagem , Extratos Vegetais/análise , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA