Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Sci Food Agric ; 97(15): 5074-5082, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28417455

RESUMO

BACKGROUND: One of the most promising uses of whey permeate (WP) is the synthesis of prebiotic oligosaccharides. Herein, commercial WP was submitted to chemical isomerization catalysed by sodium borate at an alkaline pH and subsequent purification using anion-exchange resins to remove boron. Subsequently, purified mixtures were used to synthesize prebiotic oligosaccharides using ß-galactosidase from Bacillus circulans. RESULTS: Isomerization of concentrated WP (200 g L-1 lactose) gave rise to levels of lactulose up to 155.5 g L-1 after 30 min of reaction (molar ratio of boron/lactose, 1/1; pH 12; 70 °C). Boron was removed from the isomerized WP (IWP) using the combination of a strong acid (IR-120, H+ ) and a weak base (IRA-743) anion-exchange resins, reducing its level to <1 ppm, without loss of lactulose. During the transglycosylation reaction of purified IWP (lactose/lactulose ratio, 1/2.4) maximum content of prebiotic compounds was achieved, i.e. 690 g kg-1 WP after 3 h of reaction. CONCLUSION: This study shows that combined chemical-enzymatic reactions together with the purification of IWP results in an efficient synthesis of prebiotic oligosaccharides. © 2017 Society of Chemical Industry.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/química , Lactulose/química , Oligossacarídeos/química , Prebióticos/análise , Soro do Leite/química , beta-Galactosidase/química , Biocatálise , Isomerismo , Oligossacarídeos/isolamento & purificação
2.
Nutr J ; 14: 94, 2015 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-26353756

RESUMO

BACKGROUND: Diverse enzymatic and non-enzymatic antioxidants provide protection against reactive oxygen species in humans and other organisms. The nonenzymatic antioxidants include low molecular mass molecules such as plant-derived phenols. AIM OF STUDY: This study identified the major phenolic compounds of a grape seed extract by HPLC and analyzed the effect of consumption of biscuits enriched with this extract on the urinary oxidative status of healthy subjects by measurement of urine redox potential. METHODS: The major phenolic compounds were characterized in a red grape seed extract separated by HPLC with detection by a photodiode array (PDA), fluorescence (FL) and quadrupole mass spectrometer (MS). A nutritional study in a healthy volunteers group was done. Each volunteer ate eight traditional biscuits with no red grape seed extract supplementation. The second day each volunteer ate eight traditional biscuits supplemented with 0.6% (wt/wt) of grape seed extract. An overnight urine sample was obtained for each treatment. The redox potential was measured at 25 °C using a potentiometer in each urine sample. RESULTS: Epicatechin, catechin, procyanidin dimers B1 to B4, and the procyanidin trimer C2 were the major phenolic components in the extract. Epicatechin gallate and procyanidin dimers B1-3-G and B2-3'-G were the major galloylated flavan-3-ols. The forty-six healthy volunteers each shown a reduction of the urine redox potential after the treatment by traditional biscuits supplemented with the grape seed extract. CONCLUSIONS: This simple dietary intervention significantly reduced (33%) the urine redox potential, reflecting an overall increase in antioxidant status. Incorporation of plant-derived phenols in the diet may increase anti-oxidative status.


Assuntos
Antioxidantes/administração & dosagem , Extrato de Sementes de Uva/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Fenóis/administração & dosagem , Vitis/química , Adolescente , Adulto , Biflavonoides/administração & dosagem , Biflavonoides/urina , Catequina/administração & dosagem , Catequina/análogos & derivados , Catequina/urina , Cromatografia Líquida de Alta Pressão , Suplementos Nutricionais , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Fenóis/urina , Proantocianidinas/administração & dosagem , Proantocianidinas/urina , Espécies Reativas de Oxigênio/metabolismo , Sementes/química , Adulto Jovem
3.
Anal Bioanal Chem ; 405(13): 4627-38, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23224621

RESUMO

In this work, the development and optimization of a new methodology to analyze grape seed procyanidins based on the application of two-dimensional comprehensive LC is presented. This two-dimensional method involves the use of a microbore column containing a diol stationary phase in the first dimension coupled to either a C18 partially porous short column or a C18 monolithic column in the second dimension. The orthogonal hydrophilic interaction × reversed phase liquid chromatography (HILIC×RP-LC) system is interfaced through a ten-port two-position switching valve. The optimized HILIC×RP-LC separation followed by diode array and tandem mass spectrometry detection (HILIC×RP-LC-DAD-MS/MS) made possible the direct analysis of a complex grape seed extract and allowed the tentative identification of 43 flavan-3-ols, including monomers and procyanidin oligomers till a polymerization degree of 7 units with different galloylation degrees. To the best of our knowledge, this is the first time that this powerful analytical technique is employed to characterize complex procyanidin samples. This work successfully demonstrates the great capabilities of the HILIC×RP-LC-DAD-MS/MS coupling for the direct analysis of very complex natural samples like grape seeds.


Assuntos
Proantocianidinas/análise , Sementes/química , Vitis/química , Cromatografia de Fase Reversa/instrumentação , Interações Hidrofóbicas e Hidrofílicas , Proantocianidinas/classificação , Espectrometria de Massas em Tandem/instrumentação
4.
J Chromatogr A ; 1696: 463957, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37030127

RESUMO

Although it is widely known that proanthocyanidins elute at an increasing order of molecular masses when analysed by normal phase high performance liquid chromatography (NP-HPLC), there is no a consistent explanation of the mechanisms of their separation until now. Therefore, the aim of the present study was to give a reliable response to this question, using a complex procyanidin-rich grape seed extract. For this, an off-column static simulation of extract injection and a fragmented-column dynamic procyanidin location tests were studied to show their precipitation in an aprotic solvent, besides another off-column static simulation and multiple contact dynamic solubilisation tests to confirm procyanidin redissolution in an aprotic/protic solvent system. The results showed that separation of procyanidins in the aprotic/protic solvent system of Diol-NP-HPLC was governed by precipitation/redissolution mechanism, that could be extended to all known plant proanthocyanidin homopolymers, including hydrolysable tannins, if they are able to accomplish this condition. However, separation of monomer species, namely catechins and some hydroxybenzoic acids, was based on classic adsorption/partition mechanism. Other factors, such as analyte solubility, chromatographic conditions and sample preparation, that affect the viability of proanthocyanidin analysis by NP-HPLC were stand out and guidelines for its durable and reproducible use were defined.


Assuntos
Catequina , Proantocianidinas , Proantocianidinas/análise , Cromatografia Líquida de Alta Pressão/métodos , Catequina/análise , Peso Molecular , Solventes
5.
Antibiotics (Basel) ; 12(1)2022 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-36671227

RESUMO

Campylobacter spp. are the main cause of bacterial gastroenteritis worldwide, and broiler chicks are the main vector of transmission to humans. The high prevalence of Campylobacter in poultry meat and the increase of antibiotic resistant strains have raised the need to identify new antimicrobial agents. For this reason, the aim of the current study was to evaluate the antibacterial activity of two extracts of olive leaf against antibiotic-resistant Campylobacter strains (C. jejuni and C. coli) isolated from poultry food chain. The extracts of olive leaf (E1 and E2) were markedly different in their chemical compositions. While E1 was composed predominantly of highly hydrophilic compounds such as hydroxytyrosol and hydroxytyrosol glucosides (14,708 mg/100 g), E2 mainly contained moderately hydrophilic compounds, with oleuropein (20,471 mg/100 g) being prevalent. All Campylobacter strains exhibited similar antibiotic profiles, being resistant to ciprofloxacin and tetracycline. E1 showed strong antibacterial activity and reduced bacterial growth from 4.12 to 8.14 log CFU/mL, depending on the strain. Hydroxytyrosol was the main compound responsible, causing the inhibition of growth of Campylobacter strains at low concentrations (0.1-0.25 mg/mL). E2 demonstrated a lower antibacterial effect than E1, reducing growth from 0.52 to 2.49 log CFU/mL. The results of this study suggest that the optimization of the composition of olive-leaf extracts can provide improved treatment results against Campylobacter strains.

6.
Foods ; 11(13)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35804647

RESUMO

The aim of this work was to evaluate the influence of in vitro gastric digestion of two olive leaf extracts (E1 and E2) on their chemical composition and bioactive properties against Helicobacter pylori (H. pylori), one of the most successful and prevalent human pathogens. HPLC-PAD/MS analysis and anti-inflammatory, antioxidant, and antibacterial activities of both olive leaf extracts were carried out before and after their in vitro gastric digestion. The results showed that gastric digestion produced modifications of the chemical composition and bioactive properties of both olive leaf extracts. The main compounds in the extract E1 were hydroxytyrosol and its glucoside derivatives (14,556 mg/100 g), presenting all the identified compounds a more polar character than those found in the E2 extract. E2 showed a higher concentration of less polar compounds than E1 extract, with oleuropein (21,419 mg/100 g) being the major component. Gastric digestion during the fasted state (pH 2) induced an overall decrease of the most identified compounds. In the extract E1, while the anti-inflammatory capacity showed only a slight decrease (9% of IL-8 production), the antioxidant properties suffered a drastic drop (23% of ROS inhibition), as well as the antibacterial capacity. However, in the extract E2, these changes caused an increase in the anti-inflammatory (19% of IL-8 production) and antioxidant activity (9% of ROS inhibition), which could be due to the hydrolysis of oleuropein and ligustroside into their main degradation products, hydroxytyrosol and tyrosol, but the antibacterial activity was reduced. Gastric digestion during fed state (pH 5) had less influence on the composition of the extracts, affecting in a lesser degree their anti-inflammatory and antioxidant activity, although there was a decrease in the antibacterial activity in both extracts similar to that observed at pH 2.

7.
Antioxidants (Basel) ; 10(5)2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33925096

RESUMO

Grape seeds (GS) and grape skins (GK) are natural sources of polyphenols with featured antioxidant capacity. An experiment was conducted to investigate the effect of these polyphenol sources in diets formulated to contain the same total extractable grape polyphenol content on growth performance, protein and extractable polyphenol digestibility, plasma and meat α- and γ-tocopherol and thigh meat oxidation in broiler chickens. Five experimental diets were formulated: control, control + vitamin E (200 mg/kg), 30 g/kg GS diet, 110 g/kg GK diet, GS + GK diet (a mixture of 24.4 g/kg GS and 13.1 g/kg GK designed to simulate a reconstituted grape pomace). Feeding chickens with 110 g/kg GK reduced (p < 0.001) daily weight gain, worsened (p < 0.001) feed conversion ratio, increased (p < 0.001) non-extractable polyphenol content in the ileum and in the excreta and decreased (p < 0.05) ileal protein digestibility. Regardless of the grape polyphenol source used, the inclusion of grape byproducts in the diets led to an increase of total extractable polyphenol contents in the ileum (p < 0.01) and the excreta (p < 0.001), which resulted (p < 0.001) in a decrease of extractable polyphenol digestibilities. Alpha- and gamma-tocopherol concentrations increased (p < 0.001) in plasma and in seven-day stored meat in birds fed the diet combining GS and GK with respect to the control group. As it happened with the vitamin E supplementation, feeding the combination of GS and GK also reduced (p < 0.001) the concentration of the lipid peroxidation marker (malondialdehyde) in the stored meat of chickens.

8.
Antivir Chem Chemother ; 29: 20402066211063391, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34839747

RESUMO

Seasonal flu is caused by influenza infection, a virus that spreads easily in human population with periodical epidemic outbreaks. The high mutational rate of influenza viruses leads to the emergence of strains resistant to the current treatments. Due to that, scientific research is focusing on the development of new anti-influenza agents as alternative or complementary treatments. Olive tree (Olea europaea L.) has been a source of ancestral remedies due to its antimicrobial activity. Thus, the aim of this study was to test the anti-influenza activity of a standardized olive leaf extract rich in elenolic acid (EA), Isenolic®, compared with oseltamivir. Isenolic® extract was characterized by High Performance Liquid Chromatography (HPLC)-Mass Spectrometry and its content in EA was determined by HPLC. Cytotoxicity, viral neuraminidase inhibitor activity and cell viability protection against influenza infection of Isenolic® were tested in vitro using sialic acid overexpressing Madin-Darby Canine Kidney cells. Isenolic® formulations showed a 4% and 8% dry basis. Oseltamivir and Isenolic® extracts showed anti-influenza activity. The 8% Isenolic® formulation showed a dose-dependent neuraminidase inhibitor activity higher than the 4% formulation, and preserved cell viability under viral infection. Thus, Isenolic® become a promising natural alternative to existing influenza treatments.


Assuntos
Influenza Humana , Olea , Orthomyxoviridae , Animais , Antivirais/farmacologia , Cães , Farmacorresistência Viral , Humanos , Células Madin Darby de Rim Canino , Neuraminidase , Oseltamivir , Extratos Vegetais/farmacologia , Piranos
9.
Antioxidants (Basel) ; 10(12)2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34943133

RESUMO

Helicobacter pylori (H. pylori) is one of the major human pathogens and the main cause of pathological damages that can progress from chronic gastritis to gastric cancer. During the colonization of gastric mucosa, this bacterium provokes a strong inflammatory response and subsequent oxidative process, which are associated with tissue damage. Therefore, the objective of this research was to evaluate the ability of two olive-leaf extracts (E1 and E2) to modulate the inflammatory response and oxidative stress in H. pylori-infected human gastric AGS cells. The obtained results showed that both extracts significantly decreased interleukin-8 (IL-8) secretion and reactive oxygen species (ROS) production in human gastric AGS cells. Both extracts also showed antibacterial activity against different H. pylori strains. HPLC-PAD-MS characterization demonstrated that extract E1 was mainly composed of highly hydrophilic compounds, such as hydroxytyrosol (HT) and its glucosides, and it was the most effective extract as an antibacterial agent. In contrast, extract E2 was composed mostly of moderately hydrophilic compounds, such as oleuropein (OLE), and it was more effective than extract E1 as an anti-inflammatory agent. Both extracts exhibited similar potential to decrease ROS production. These results show the importance of standardizing the extract composition according to the bioactive properties that should be potentiated.

10.
Antioxidants (Basel) ; 10(6)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208004

RESUMO

Helicobacter pylori (H. pylori) is a pathogenic bacteria identified as a potential risk factor for gastritis, gastric ulcers and gastric cancer. During the stomach colonization, H. pylori triggers a strong inflammatory response and subsequent oxidative stress, which are associated with tissue damage. For this reason, it is of particular interest to develop alternative natural tools that enable modulation of the associated damaging immune response. With this purpose, we obtained grape seed extract (GSE) from sweet (not fermented) food grade seeds. The aim of our study was to investigate the effect of GSE and its two enriched procyanidins fractions (OPC and PPC) on the inflammatory process and oxidative stress produced by different H. pylori strains in human gastric epithelial cells (AGS). Anti-inflammatory activity was evaluated by measuring the level of interleukin-8 (IL-8) secretion. IL-8 production was significantly reduced in H. pylori-infected human gastric epithelial cells pre-treated with GSE or its enriched fractions when compared with non-pre-treated infected cells (from 21.6% to 87.8%). Pre-treatment with GSE or its fractions significantly decreased intracellular reactive oxygen species (ROS) production in AGS cells after infection, depending on the H. pylori strain. Our results also showed that GSE and its fractions demonstrate antibacterial activity against all strains of H. pylori used in the study. This work demonstrates the effectiveness of GSE enriched in procyanidins against the main events associated with H. pylori infection.

11.
Sci Rep ; 11(1): 8188, 2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33854149

RESUMO

Olive leaves are rich in bioactive substances which exert anti-inflammatory, antioxidant, insulin-sensitizing and antihypertensive effects. The aim of this study was to analyze the possible beneficial effects of an olive leaf extract (OLE) rich in secoiridoids and phenolic compounds on the aging-induced metabolic and vascular alterations. Three experimental groups of rats were used: 3-month-old rats, 24-month-old rats and 24-month-old rats supplemented 21 days with OLE (100 mg/kg). Administration of OLE to aged rats decreased the weight of adrenal glands and prevented the aging-induced loss of body weight and muscle mass. In the serum, OLE reduced the circulating levels of LDL-cholesterol and IL-6 and increased the concentrations of leptin and adiponectin. In the liver OLE attenuated the decreased gene expression of SOD-1, GSR, GCK and GSK-3ß and reduced the aging-induced overexpression of NOX-4, Alox-5, iNOS and TNF-α. In aorta segments, OLE prevented endothelial dysfunction and vascular insulin resistance and improved vasoconstriction in response to KCl and NA. Improvement in vascular function was associated with the attenuation of the alterations in the gene expression of COX-2, IL-6, GPx, NOX-1 and IL-10. In conclusion, OLE exerts anti-inflammatory and antioxidant effects in aged rats and attenuates the alterations in vascular function associated with aging.


Assuntos
Envelhecimento/efeitos dos fármacos , LDL-Colesterol/sangue , Redes Reguladoras de Genes/efeitos dos fármacos , Interleucina-6/sangue , Leptina/sangue , Estresse Oxidativo/efeitos dos fármacos , Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/metabolismo , Envelhecimento/sangue , Envelhecimento/genética , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Modelos Animais , Olea , Tamanho do Órgão/efeitos dos fármacos , Folhas de Planta , Ratos , Ratos Wistar
12.
Foods ; 9(5)2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32397247

RESUMO

Pressurized liquid extraction with ethanol:water mixtures was proposed for obtaining phenolic antioxidants from grape stems. The optimal extraction conditions were elucidated by using a central composite rotatable design (solvent (X1, 0-100% ethanol:water v/v), temperature (X2, 40-120 °C) and time (X3, 1-11 min)). Response surface methodology determined 30% ethanol:water, 120 °C and 10 min as the optimal extraction conditions regarding total phenolic content (TPC) (185.3 ± 2.9 mg gallic acid/g of extract) and antioxidant activity (3.55 ± 0.21 mmol Trolox/g, 1.22 ± 0.06 mmol Trolox/g and 1.48 ± 0.17 mmol Trolox/g of extract in ABTS, DPPH and ORAC methodologies, respectively). The antioxidant activity was attributed to total polymer procyanidins and flavan-3-ol monomers and oligomers, although other phenolic compound contributions should not be ruled out. Forty-two phenolic compounds were identified in the optimal extract, mainly polymer procyanidins and, to a lesser extent, monomers and oligomers of flavan-3-ols, quercetin-3-O-glucuronide, ε-viniferin, gallic and caftaric acid. Ethyl gallate, ellagic acid, protocatechuic aldehyde, delphinidin-7-O-glucoside and cyanidin-3-O-glucoside were reported for the first time in grape stem extracts. In conclusion, this study highlights the use of this winery side stream as a source of antioxidants within a sustainable food system.

13.
Artigo em Inglês | MEDLINE | ID: mdl-32089715

RESUMO

There are few studies about the pharmacokinetics of the low-molecular mass carotenoids crocetin or crocin isomers from saffron (Crocus sativus L.). None has been performed with a galenic preparation of a standardised saffron extract. The aim of the present research work was to study the effect of in vitro digestion process on the main bioactive components of saffron extract tablets and the corresponding pharmacokinetic parameters in humans. Pharmacokinetics were calculated collecting blood samples every 30 min during the first 3 h and at 24 h after administration of two different concentrations (56 and 84 mg of the saffron extract) to 13 healthy human volunteers. Additionally, an in vitro digestion process was performed in order to determine the bioaccessibility of saffron main bioactive compounds. Identification and quantification analysis were performed by HPLC-PAD/MS. Digestion resulted in 40% of bioaccesibility for crocin isomers, whereas, safranal content followed an opposite trend increasing about 2 folds its initial concentration after the digestion process. Crocetin in plasma was detected in a maximum concentration (C max) in blood between 60 and 90 min after oral consumption with dose-dependent response kinetics, showing that crocin isomers from galenic preparation of saffron extract are rapidly transformed into crocetin. The results showed that this tested galenic form is an efficient way to administer a saffron extract, since the observed crocetin C max was similar and more quickly bioavailable than those obtained by other studies with much higher concentrations of crocetin.

14.
Food Chem ; 318: 126476, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32143132

RESUMO

A pilot-scale extraction of sunflower pectin with 0.74% (w/v) sodium citrate (72 °C, 194 min) and different procedures of purification including alcohol precipitation, ultrafiltration (UFDF) and microfiltration (MFDF) with diafiltration were carried out. Considering the alcohol treatment, the yields were similar at laboratory and pilot-scale (~8.9%), demonstrating the efficiency of the scale-up. With respect to membrane processes, the best results were obtained with UFDF, showing the highest yield (13.3%) and pectin concentration higher than 90%. In all cases, pectins presented very low amount (~1%) of glucose and mannose, monosaccharides not included in the pectin structure. Detailed NMR analysis and functional properties (emulsifying and viscosity) that were also assessed corroborated the good quality of UFDF obtained pectin. These results point out that the obtainment of sunflower pectin of good quality can be achieved at pilot-scale by the extraction with sodium citrate and purification with membrane separation, eco-friendly alternatives to conventional procedures.


Assuntos
Helianthus/química , Pectinas/química , Pectinas/isolamento & purificação , Fracionamento Químico , Emulsificantes/química , Citrato de Sódio/química , Ultrafiltração/métodos , Viscosidade
15.
Foods ; 9(10)2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32993186

RESUMO

Strains of Helicobacter pylori (H. pylori) resistant to various antibiotics have increased in recent years. In this context, the search for new therapeutic approaches is crucial. The aim of the present study was to demonstrate the antibacterial activity of a procyanidin-rich extract obtained from food-grade winery grape seeds against 14 H. pylori strains and elucidate its phenolic composition. Ten strains (71.4%) showed resistance to at least some of the tested antibiotics, while four isolates (28.6%) were susceptible to all antibiotics. Resistance to more than one class of antibiotics was observed in six strains (42.9%). The extract was able to inhibit the growth of all H. pylori strains in a range of a minimum inhibitory concentration (MIC) from 0.015 mg/mL to 0.125 mg/mL, confirming also the existence of a strain-dependent effect. The phenolic composition determined by reverse phase high pressure liquid chromatography, photodiode array, and mass spectrometry detection (RP-HPLC-PAD-MS) analysis revealed the presence of 43 individual compounds and allowed the quantification of 41 of them, including seven procyanidin tetramers, seven procyanidin pentamers, and six galloylated procyanidin dimers, trimers, and tetramers. The extract was composed mainly by catechin and procyanidin oligomers with a total amount of 5.801 mg/100 g, which represent 92% of the total individual phenolic content. Among them, the most abundant were catechins (2.047 mg/100 g), followed by procyanidin dimers (1.550 mg/100 g), trimers (1.176 mg/100 g), tetramers (436 mg/100 g), and pentamers (296 mg/100 g) that represent 35, 27, 20, 8, and 5%, respectively of the total flavanol constituents. The composition profile information may help to improve the production process of useful antibacterial extracts against H. pylori.

16.
J Fungi (Basel) ; 6(3)2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32785198

RESUMO

Penicillium rubens strain 212 (PO212) acts as an inducer of systemic resistance in tomato plants. The effect of crude extracellular extracts of PO212 on the soil-borne pathogen Fusarium oxysporum f. sp. lycopersici has been evaluated. Evidence of the involvement of soluble, thermo-labile, and proteinase-inactivated macromolecules present in PO212 crude extracts in the control of Fusarium vascular disease in tomato plants was found. Proteomic techniques and the availability of the access to the PO212 genome database have allowed the identification of glycosyl hydrolases, oxidases, and peptidases in these extracellular extracts. Furthermore, a bioassay-guided fractionation of PO212 crude extracellular extracts using an integrated membrane/solid phase extraction process was set up. This method enabled the separation of a PO212 crude extracellular extract of seven days of growth into four fractions of different molecular sizes and polarities: high molecular mass protein fraction >5 kDa, middle molecular mass protein fraction 5-1 kDa, low molecular mass metabolite fraction, and nutrients from culture medium (mainly glucose and minerals). The high and middle molecular mass protein fractions retained disease control activity in a way similar to that of the control extracts. Proteomic techniques have allowed the identification of nine putatively secreted proteins in the high molecular mass protein fraction matching those identified in the total crude extracts. Therefore, these enzymes are considered to be potentially responsible of the crude extracellular extract-induced resistance in tomato plants against F. oxysporum f. sp. lycopersici. Further studies are required to establish which of the identified proteins participate in the PO212's action mode as a biocontrol agent.

17.
Membranes (Basel) ; 10(7)2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32660066

RESUMO

The effectiveness of a preparative integrated ultrafiltration/solid-phase extraction (UF/SPE) process for purification of oligomeric procyanidins (OPCs) from a crude grape seed extract (GSE) was studied for the first time. The separation of OPCs from polymeric procyanidins (PPCs) by UF was very efficient. The membrane showed an acceptable filtration flux of 6 to 3.5 L/h·m2 at 0.5 bar of transmembrane pressure and 95% recovery of its water flux after chemical cleaning. The process was scalable to a pilot scale. The separation of very polar and ionic species from OPCs by SPE (XAD7HP and XAD16 resins) was also very good, but both adsorbents lost their retention capacities quickly, due probably to irreversible retention of OPCs/PPCs. Even though the global purification of OPCs by the integrated UF/SPE process allowed the recovery of 24.2 g of highly purified OPCs (83% purity) from 14.4 L of crude grape seed extract, the use of these adsorbents for further purification of the OPCs was very limited.

18.
Antioxidants (Basel) ; 9(4)2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32326269

RESUMO

The incidence of metabolic syndrome (MetS) is increasing worldwide which makes necessary the finding of new strategies to treat and/or prevent it. The aim of this study was to analyze the possible beneficial effects of a carob fruit extract (CSAT+®) on the cardiometabolic alterations associated with MetS in mice. 16-week-old C57BL/6J male mice were fed for 26 weeks either with a standard diet (chow) or with a diet rich in fats and sugars (HFHS), supplemented or not with 4.8% of CSAT+®. CSAT+® supplementation reduced blood glucose, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and circulating levels of total cholesterol, low-density lipoprotein (LDL) cholesterol (LDL-c), insulin, and interleukin-6 (IL-6). In adipose tissue and skeletal muscle, CSAT+® prevented MetS-induced insulin resistance, reduced macrophage infiltration and the expression of pro-inflammatory markers, and up-regulated the mRNA levels of antioxidant markers. Supplementation with CSAT+® prevented MetS-induced hypertension and decreased the vascular response of aortic rings to angiotensin II (AngII). Moreover, treatment with CSAT+® attenuated endothelial dysfunction and increased vascular sensitivity to insulin. In the heart, CSAT+® supplementation reduced cardiomyocyte apoptosis and prevented ischemia-reperfusion-induced decrease in cardiac contractility. The beneficial effects at the cardiovascular level were associated with a lower expression of pro-inflammatory and pro-oxidant markers in aortic and cardiac tissues.

19.
Plant Foods Hum Nutr ; 64(4): 238-43, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19821030

RESUMO

Phenolic composition of wine depends not only on the grape variety from which it is made, but on some external factors such as winemaking technology. Red wine possesses the most antioxidant effect because of its high polyphenolic content. The aim of this work is to study for the first time, the neuroprotective activity of four monovarietal Spanish red wines (Merlot (ME), Tempranillo (T), Garnacha (G) and Cabernet-Sauvignon (CS)) through its antioxidant ability, and to relate this neuroprotection to its polyphenolic composition, if possible. The wine effect on neuroprotection was studied through its effect as free radical scavenger against FeSO4, H2O2 and FeSO4 + H2O2. Effect on cell survival was determined by 3(4,5-dimethyltiazol-2-il)-2,5-diphenyltetrazolium reduction assay (MTT) and lactate dehydrogenase (LDH) release assay on astrocytes cultures. Results showed that most of the studied wine varieties induced neuroprotection through their antioxidant ability in astrocytes, Merlot being the most active; this variety is especially rich in phenolic compounds, mainly catechins and oligomeric proanthocyanidins. Our results show that red wine exerts a protection against oxidative stress generated by different toxic agents and that the observed neuroprotective activity is related to their polyphenolic content.


Assuntos
Antioxidantes/farmacologia , Astrócitos/efeitos dos fármacos , Flavonoides/farmacologia , Fármacos Neuroprotetores/farmacologia , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Vitis/química , Vinho , Astrócitos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Frutas , Humanos , L-Lactato Desidrogenase/metabolismo , Polifenóis
20.
Ultrason Sonochem ; 50: 74-81, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30219355

RESUMO

The impact of high intensity ultrasound (US, 45 and 20 kHz) on a purified macromolecular fraction (more than 85% of polymeric procyanidins) from grape seed extract was investigated. Matrix-Assisted Laser Desorption/Ionisation (MALDI-TOF), Reverse Phase High Performance Liquid Chromatography (RP-HPLC) and Fourier-transform infrared spectroscopy (FTIR) revealed a modification in the chemical structure of these macromolecules treated by US and, particularly, bath US produced a considerable increase of up to 49, 41 and 35%, respectively, of catechins and oligomeric and polymeric procyanidin contents of the treated purified fraction. Bath US also produced an important increase in the number of procyanidins with higher molecular mass (up to decamers) and an overall increase in the mass signal intensities in most of the detected B-type procyanidin series, as well as an important increase of the antioxidant activity of the macromolecular fraction of procyanidins. These results could be ascribed to a certain disaggregation of procyanidins linked to other biopolymers, such as proteins and/or polysaccharides, indicating that US is an efficient technology to modify the chemical structure and hence the bioactivity of tannins.


Assuntos
Antioxidantes/farmacologia , Biflavonoides/análise , Catequina/análise , Extrato de Sementes de Uva/farmacologia , Extratos Vegetais/farmacologia , Proantocianidinas/análise , Ondas Ultrassônicas , Biflavonoides/química , Catequina/química , Cromatografia Líquida de Alta Pressão , Extrato de Sementes de Uva/química , Peso Molecular , Extratos Vegetais/química , Proantocianidinas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectroscopia de Infravermelho com Transformada de Fourier
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA