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1.
Mol Plant Pathol ; 25(3): e13440, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38460111

RESUMO

Given the detrimental effects of excessive reactive oxygen species (ROS) accumulation in plant cells, various antioxidant mechanisms have evolved to maintain cellular redox homeostasis, encompassing both enzymatic components (e.g., catalase, superoxide dismutase) and non-enzymatic ones. Despite extensive research on the role of antioxidant systems in plant physiology and responses to abiotic stresses, the potential exploitation of antioxidant enzymes by plant viruses to facilitate viral infection remains insufficiently addressed. Herein, we demonstrate that maize catalases (ZmCATs) exhibited up-regulated enzymatic activities upon sugarcane mosaic virus (SCMV) infection. ZmCATs played crucial roles in SCMV multiplication and infection by catalysing the decomposition of excess cellular H2 O2 and promoting the accumulation of viral replication-related cylindrical inclusion (CI) protein through interaction. Peroxisome-localized ZmCATs were found to be distributed around SCMV replication vesicles in Nicotiana benthamiana leaves. Additionally, the helper component-protease (HC-Pro) of SCMV interacted with ZmCATs and enhanced catalase activities to promote viral accumulation. This study unveils a significant involvement of maize catalases in modulating SCMV multiplication and infection through interaction with two viral factors, thereby enhancing our understanding regarding viral strategies for manipulating host antioxidant mechanisms towards robust viral accumulation.


Assuntos
Potyvirus , Zea mays , Catalase , Antioxidantes , Potyvirus/fisiologia , Replicação Viral , Doenças das Plantas
2.
Materials (Basel) ; 16(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37445065

RESUMO

Welding is prone to several defects. To test the fatigue properties of the welded defective joints of high-speed rail bogies, SMA490BW steel cruciform welded joints were employed with artificial defects treatment. Consequently, fatigue tests were conducted on the specimens. Fatigue fracture morphology was studied via scanning electron microscopy. The ABAQUS (version 2022) finite element software was used to calculate the stress distribution and concentration factor of cruciform welded joints with defects. The results show that the fatigue limits of 1 and 2.4 mm defect specimens were approximately 57.2 and 53.75 Mpa, respectively. Furthermore, the stress concentration factor of no, 1 mm, and 2.4 mm defects were 2.246, 4.441, and 6.684, respectively, indicating that the stress concentration factor of 1 and 2.4 mm defects increased by 98 and 198%, respectively, with respect to the no-defect case.

3.
Materials (Basel) ; 15(21)2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36363147

RESUMO

It has been previously noted that the development of aerospace material technology and breakthroughs are inseparable when obtaining great achievements in the aerospace industry. Materials are the basis and precursor of modern high technology and industry. As one of the most powerful aluminium alloys, 7050 is widely used in the aerospace field. In this manuscript, the vibration fatigue behaviour of aircraft aluminium alloy 7050 is studied based on experiments. A vibration fatigue experiment and the traditional fatigue testing of aluminium alloy 7050 were performed. We found that there was an extreme difference between the vibration fatigue and the traditional fatigue curves. In addition, the experimental end criteria for the vibration fatigue experiment of aluminium alloy 7050 was obtained from the acceleration reduction and the frequency reduction value. For the acceleration experimental end criterion, 2% was the acceleration reduction value for the vibration fatigue experimental end criteria of aluminium alloy 7050. For the frequency experimental end criterion, 2% was the frequency reduction value for the vibration fatigue experimental end criteria of aluminium alloy 7050.

4.
Materials (Basel) ; 16(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36614467

RESUMO

High-speed trains have a large amount of ancillary equipment, which is suspended from the underside of the train by means of a suspension structure. Due to the large mass of the ancillary equipment, the suspension structure is subjected to various loads during train operation and there is a risk of fatigue failure. In this paper, the stress distribution at the suspension point and the lo-cation of the maximum stress point under load are investigated in detail based on actual test loads at the suspension point and finite element simulation analysis. In order to further investigate the fracture failure of the suspension points, experimental studies were carried out. Firstly, static strength tests were carried out to obtain the load-displacement curves of the structural members and to determine the fracture strength of the structure based on the displacement sensors, and secondly, fatigue tests at different stress levels were carried out to obtain the load-life curves of the structural members and to investigate the probabilistic load-life curves at different reliability levels. The test results show that the structural component has a high fracture strength of 65kN, while the conditional fatigue strength is relatively low, corresponding to a load level of 12.5kN at a median life of 106 cycles. The above research work provides the necessary basis for the design, optimization and reliability assessment of the suspension structures of high-speed trains.

5.
Sci Rep ; 11(1): 19279, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34588550

RESUMO

The fatigue strength of a component is known to highly depend on its surface quality, and it is thus necessary to develop a reliable and appropriate mathematical model for fatigue strength assessment that consider the effect of surface roughness. In this paper, different underlying physical mechanisms of the roughness effect at different regions of specimens were studied by fatigue testing of 7N01 aluminum alloy. For a quantitative analysis of the surface roughness effect, a revised stress field intensity approach for a fatigue strength assessment of microsized notches was proposed as a theoretical support. In the new model, a new form of weight function was built to adapt the characteristics of microsized notches. In addition, the effect of the field radius was fundamentally weakened on solution of the stress field intensity and the difficulty of fatigue failure region definition in the traditional method was overcome correspondingly in the proposed model, which made the calculated field strength accurate and objective. Finally, to demonstrate the validity of the revised approach quantitatively, specimens with conventionally sized notches were subjected to stress field intensity calculations. The results showed that the revised approach has satisfactory accuracy compared with the other two traditional approaches from the perspective of quantitative analysis.

6.
J Epidemiol Community Health ; 75(11): 1104-1110, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33893183

RESUMO

OBJECTIVE: As elderly parents today will share a longer life with their children than ever before, the spillover effects of children's human capital on parents' well-being become increasingly important. This study investigated whether children's schooling leads parents to give up smoking and whether the effects were moderated by their education or child-parent contact frequency. METHODS: Using data from the China Health and Retirement Longitudinal Study, we conducted an instrumental variable (IV) analysis using China's compulsory schooling reform in the 1980s as a natural experiment. RESULTS: The IV estimates suggest that elderly parents of more highly educated children are more likely to quit smoking. Moreover, the effects are more significant among parents who had not finished primary school and also slightly stronger among parents who live close to their children or meet their children frequently. DISCUSSION: Our findings add to current evidence regarding spillover effects of education on smoking cessation. A child's education may exert an impact through the spillover of health knowledge.


Assuntos
Abandono do Hábito de Fumar , Adulto , Filhos Adultos , Idoso , China/epidemiologia , Humanos , Estudos Longitudinais , Relações Pais-Filho , Pais
7.
J Sci Med Sport ; 24(2): 189-194, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33032913

RESUMO

OBJECTIVES: We aimed to estimate the association of sleep, sedentary activity and physical activity with cognitive function among older adults, with consideration of the competing nature between variables of activity status. DESIGN: Cross-sectional study. METHODS: A total of 3086 older adults (60 years or older) in the 2011-2014 National Health and Nutrition Examination Survey were included. The Global Physical Activity Questionnaire was used to measure self-reported time for sedentary activity, walking/bicycling and moderate-to-vigorous physical activity (MVPA). Cognitive function was examined using the CERAD Word Learning subtest (memory), Digit Symbol Substitution Test (executive function/processing speed), and Animal Fluency Test (language). Sleep duration was obtained via interview. Isotemporal substitution models using multivariable linear regression were applied to examine the associations of replacing sleep, sedentary activity, walking/bicycling, MVPA with each other and cognitive function, stratified by sleep duration per night (≤7h, >7h). RESULTS: Among participants with sleep duration ≤7h/night, replacing 30min/day of sedentary activity with 30min/day of MVPA or 30min/day was associated with better cognition. Among participants with sleep duration >7h/night, replacing 30min/day of sleep with 30min/day of sedentary activity, walking/bicycling, or MVPA was associated with better cognition. CONCLUSIONS: Replacing sedentary activities with MVPA was associated with favorable cognitive function among older adults sleeping no longer than 7h/night, and replacing excessive sleep with sedentary or physical activities was associated with favorable cognition. Future research is expected to examine the associations of replacing different activity status on long-term cognitive outcomes in longitudinal studies.


Assuntos
Cognição/fisiologia , Exercício Físico/psicologia , Comportamento Sedentário , Sono/fisiologia , Idoso , Estudos Transversais , Feminino , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Autorrelato , Fatores de Tempo
8.
Life Sci Space Res (Amst) ; 25: 107-118, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32414484

RESUMO

Health risks from galactic cosmic rays (GCR) in space travel above low earth orbit remain a concern. For many years accelerator experiments investigating space radiation induced prevalence of murine Harderian gland (HG) tumorigenesis have been performed to help estimate GCR risks. Most studies used acute, relatively low fluence, exposures. Results on a broad spectrum of individual ions and linear energy transfers (LETs) have become available. However, in space, the crew are exposed simultaneously to many different GCR. Recent upgrades at the Brookhaven NASA Space Radiation Laboratory (NSRL) now allow mixtures in the form of different one-ion beams delivered in rapid sequence. This paper uses the results of three two-ion mixture experiments to illustrate conceptual, mathematical, computational, and statistical aspects of synergy analyses and also acts as an interim report on the mixture experiments' results. The results were interpreted using the following: (a) accumulated data from HG one-ion accelerator experiments; (b) incremental effect additivity synergy theory rather than simple effect additivity synergy theory; (c) parsimonious models for one-ion dose-effect relations; and (d), computer-implemented numerical methods encapsulated in freely available open source customized software. The main conclusions are the following. As yet, the murine HG tumorigenesis experimental studies show synergy in only one case out of three. Moreover, some theoretical arguments suggest GCR-simulating mixed beams are not likely to be synergistic. However, more studies relevant to possible synergy are needed by various groups that are studying various endpoints. Especially important is the possibility of synergy among high-LET radiations, since individual high-LET ions have large relative biological effectiveness for many endpoints. Selected terminology, symbols, and abbreviations. DER - dose-effect relation; E(d) - DER of a one-ion beam, where d is dose; HG prevalence p - in this paper, p is the number of mice with at least one Harderian gland tumor divided by the number of mice that are at risk of developing Harderian gland tumors (so that in this paper prevalence p can never, conceptually speaking, be greater than 1); IEA - incremental effect additivity synergy theory; synergy level - a specification, exemplified in Fig. 5, of how clear-cut an observed synergy is; mixmix principle - a consistency condition on a synergy theory which insures that the synergy theory treats mixtures of agent mixtures in a mathematically self-consistent way; NTE - non-targeted effect(s); NSNA - neither synergy nor antagonism; SEA - simple effect additivity synergy theory; TE - targeted effect(s); ß* - ion speed relative to the speed of light, with 0 < ß* < 1; SLI - swift light ion(s).


Assuntos
Transformação Celular Neoplásica/efeitos da radiação , Radiação Cósmica/efeitos adversos , Glândula de Harder/efeitos da radiação , Neoplasias Induzidas por Radiação , Animais , Carcinogênese , Simulação por Computador , Glândula de Harder/patologia , Transferência Linear de Energia , Camundongos , Modelos Teóricos , Aceleradores de Partículas , Prevalência
9.
Comput Methods Programs Biomed ; 189: 105337, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31962279

RESUMO

Cancer subtype analysis, as an extension of cancer diagnosis, can be regarded as a consensus clustering problem. This analysis is beneficial for providing patients with more accurate treatment. Consensus clustering refers to a situation in which several different clusters have been obtained for a particular data set, and it is desired to aggregate those clustering results to get a better clustering solution. In this paper, we propose to generalize the traditional consensus clustering methods in three manners: (1) We provide Bregmannian consensus clustering (BCC), where the loss between the consensus clustering result and all the input clusterings are generalized from a traditional Euclidean distance to a general Bregman loss; (2) we generalize the BCC to a weighted case, where each input clustering has different weights, providing a better solution for the final clustering result; and (3) we propose a novel semi-supervised consensus clustering, which adds some must-link and cannot-link constraints compared with the first two methods. Then, we obtain three cancer (breast, lung, colorectal cancer) data sets from The Cancer Genome Atlas (TCGA). Each data set has three data types (mRNA, mircoRNA, methylation), and each is respectively used to test the accuracy of the proposed algorithms for clusterings. The experimental results demonstrate that the highest aggregation accuracy of the weighted BCC (WBCC) on cancer data sets is 90.2%. Moreover, although the lowest accuracy is 62.3%, it is higher than other methods on the same data set. Therefore, we conclude that as compared with the competition, our method is more effective.


Assuntos
Algoritmos , Perfilação da Expressão Gênica , Neoplasias/classificação , Neoplasias/genética , Análise por Conglomerados , Perfilação da Expressão Gênica/estatística & dados numéricos , Metilação , MicroRNAs , RNA Mensageiro
10.
J Affect Disord ; 257: 257-262, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31301629

RESUMO

BACKGROUND: Late-life depression is a great burden of public health. Previous studies reported that physical activity is associated with reduced depressive symptoms among older adults, while the competing nature of physical activity and sedentary behaviors has been largely neglected in studies. We aimed to examine the associations of replacing sedentary behaviors with walking/bicycling or moderate-to-vigorous physical activity (MVPA) with depressive symptoms in older adults. METHODS: A cross-sectional analysis was conducted among 8374 older adults (60 years or older) included in the National Health and Nutrition Examination Survey (NHANES), 2007-2016. The Global Physical Activity Questionnaire was used to measure self-reported time for sedentary behaviors, walking/bicycling, and MVPA. The 9-item Patient Health Questionnaire was used to measure depressive symptoms (including overall, somatic, and cognitive). Z-scores were created for depressive symptoms. Isotemporal substitution models using multivariable linear regression were applied to examine the associations of sedentary behaviors, walking/bicycling, and MVPA with z-scores of depressive symptoms. RESULTS: Replacing 30 min/day sedentary behaviors with 30 min/day of MVPA (beta (ß) = -0.10, 95% confidence interval (CI): -0.14, -0.06) or 30 min/day of walking/bicycling (ß = -0.04, 95% CI: -0.06, -0.02) was associated with lower z-score for depressive symptoms. Replacing 30 min/day of walking/bicycling for 30 min/day of MVPA was associated with lower z-score for depressive symptoms (ß = -0.06, 95% CI: -0.10, -0.02). LIMITATIONS: A cross-sectional study design precludes causal inferences. CONCLUSION: Replacing sedentary behaviors with walking/bicycling or MVPA is associated with lower depressive symptoms among older adults. Future research is expected to investigate the effectiveness of physical activity on prevention and treatment of late-life depression.


Assuntos
Depressão/diagnóstico , Exercício Físico/psicologia , Transtornos de Início Tardio/diagnóstico , Comportamento Sedentário , Acelerometria , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Psicológicos , Inquéritos Nutricionais
11.
Nutr Res ; 37: 67-77, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28215316

RESUMO

Former smokers are at increased risk for cardiovascular disease. We hypothesized that dietary aronia polyphenols would reduce biomarkers of cardiovascular disease risk, inflammation, and oxidative stress in former smokers. We also determined the extent these effects were associated with polyphenol bioavailability. A 12-week, randomized, placebo-controlled trial was conducted in 49 healthy adult former smokers (n = 24/placebo, n = 25/aronia) to evaluate if daily consumption of 500 mg aronia extract modulated plasma lipids, blood pressure, biomarkers of inflammation and oxidative stress, and lipid transport genes of peripheral blood mononuclear cells. The primary outcome was change in low-density lipoprotein cholesterol (LDL-C) from baseline, and multivariate correlation analysis was performed to determine if changes in lipids were associated with urinary polyphenol excretion. Aronia consumption reduced fasting plasma total cholesterol by 8% (P = .0140), LDL-C by 11% (P = .0285), and LDL receptor protein in peripheral blood mononuclear cells (P = .0036) at 12 weeks compared with the placebo group. Positive changes in the urinary polyphenol metabolites peonidin-3-O-galactoside, 3-(4-hydroxyphenyl) propionic acid, and unmetabolized anthocyanin cyanidin-3-O-galactoside were associated with lower plasma total cholesterol and LDL-C in the aronia group. Aronia consumption did not change blood pressure or biomarkers of inflammation and oxidative stress. Aronia polyphenols reduced total and LDL-C in former smokers but did not improve biomarkers of oxidative stress and chronic inflammation. The cholesterol-lowering activity of aronia extract was most closely associated with urinary levels of cyanidin-3-O-galactoside and peonidin-3-O-galactoside, its methylated metabolite. This trial was registered at ClinicalTrials.gov as NCT01541826.


Assuntos
LDL-Colesterol/sangue , Inflamação , Estresse Oxidativo/efeitos dos fármacos , Photinia/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Fumar , Adulto , Antocianinas/farmacologia , Antioxidantes/farmacologia , Disponibilidade Biológica , Biomarcadores/sangue , Pressão Sanguínea , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , Colesterol/sangue , Feminino , Frutas/química , Galactosídeos/farmacologia , Humanos , Inflamação/etiologia , Masculino , Fumantes , Fumar/efeitos adversos
12.
Food Chem ; 211: 860-8, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27283706

RESUMO

A single-dose pharmacokinetic trial was conducted in 6 adults to evaluate the bioavailability of anthocyanins and colonic polyphenol metabolites after consumption of 500mg aronia berry extract. UHPLC-MS methods were developed to quantitate aronia berry polyphenols and their metabolites in plasma and urine. While anthocyanins were bioavailable, microbial phenolic catabolites increased ∼10-fold more than anthocyanins in plasma and urine. Among the anthocyanins, cyanidin-3-O-galactoside was rapidly metabolized to peonidin-3-O-galactoside. Aronia polyphenols were absorbed and extensively metabolized with tmax of anthocyanins and other polyphenol catabolites from 1.0h to 6.33h in plasma and urine. Despite significant inter-individual variation in pharmacokinetic parameters, concentrations of polyphenol metabolites in plasma and urine at 24h were positively correlated with total AUC in plasma and urine (r=0.93, and r=0.98, respectively). This suggests that fasting blood and urine collections could be used to estimate polyphenol bioavailability and metabolism after aronia polyphenol consumption.


Assuntos
Antocianinas/metabolismo , Colo/metabolismo , Frutas/metabolismo , Photinia/metabolismo , Extratos Vegetais/metabolismo , Polifenóis/metabolismo , Adulto , Antocianinas/administração & dosagem , Disponibilidade Biológica , Ingestão de Alimentos/fisiologia , Feminino , Frutas/química , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Extratos Vegetais/administração & dosagem , Adulto Jovem
13.
Food Chem ; 148: 300-6, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24262561

RESUMO

Stilbene polyphenols are present in some fruits and nuts, but their abundance in many foods, such as almonds, is unknown. Therefore, we characterised stilbenes from Nonpareil, Butte and Carmel almond (Prunus dulcis) varieties from California. UHPLC-MS conditions were optimised to resolve cis- and trans-resveratrol, d4-resveratrol, dienestrol, hexestrol, oxyresveratrol, piceatannol, pterostilbene, and resveratrol-3-ß-glucoside (polydatin). Stilbenes were isolated from ethanolic almond extracts by solid-phase extraction and identified with UHPLC-MS by comparison of retention times, mass spectra, in-source CID spectra, and enzymatic hydrolysis to authentic standards. Polydatin was identified in almond extracts, with 7.19-8.52 µg/100 g almond. Piceatannol+oxyresveratrol was tentatively identified in almond blanch water, at 0.19-2.55 µg/100 g almond. Polydatin was concentrated in almond skins, which contained 95.6-97.5% of the total almond content. Therefore, almonds contain the stilbene class of polyphenols in addition to the previously identified proanthocyanidin, hydrolysable tannin, flavonoid, and phenolic acid classes.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Nozes/química , Extratos Vegetais/química , Prunus/química , Estilbenos/química , California
14.
Food Chem ; 141(1): 347-56, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23768367

RESUMO

The existing cellular antioxidant activity (CAA) assays always use chemical stressors [e.g. 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)] to initiate oxidative stress (OS), which is not accordance with the pathology of OS-related diseases. In contrast to previous cell models, an oleic acid (OA)-induced OS model of the HepG2 cells was developed in the current work. The antioxidant activities (AAs) of the 16 flavonoid standards in the CAAOA assay were significantly different from the results of the CAAAAPH and peroxyl radical-scavenging assays (PRSA). The AAs of these flavonoids in the PRSA were significantly associated with those of the CAAAAPH assay (r=0.848, P<0.01). On the other hand, isoflavones and epicatechin could significantly attenuate the OS in the CAAOA assay. However, the three flavonoids had no quantifiable AA in CAAAAPH and PRSA. The aforementioned results suggest that the CAAOA assay can probably better reflect the AAs of samples in biological systems.


Assuntos
Antioxidantes/química , Bioquímica/métodos , Células/química , Células/metabolismo , Ácido Oleico/metabolismo , Estresse Oxidativo , Antioxidantes/metabolismo , Células Hep G2 , Humanos , Ácido Oleico/química , Oxirredução
15.
Nutr Res ; 33(5): 406-13, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23684442

RESUMO

We hypothesized that a polyphenol-rich chokeberry extract (CBE) would modulate hepatic lipid metabolism and improve antioxidant function in apolipoprotein E knockout (apoE(-/-)) mice. ApoE(-/-) mice were fed diets containing 15% fat with 0.2% cholesterol alone or supplemented with 0.005% or 0.05% CBE for 4 weeks. CBE polyphenol content was determined by the total phenols, 4-dimethylaminocinnamaldehyde, and ultra high-performance liquid chromatography-mass spectrometry methods. The 0.05% CBE diet provided mice with mean daily doses of 1.2 mg gallic acid equivalents of total phenols, 0.19 mg anthocyanins, 0.17 mg phenolic acids, 0.06 mg proanthocyanidins (as catechin-equivalents), and 0.02 mg flavonols. The 0.05% CBE group had 12% less plasma total cholesterol concentrations than the control. Despite the hypocholesterolemic effect of CBE, hepatic mRNA levels of low-density lipoprotein receptor, hydroxyl-3-methylglutaryl coenzyme A reductase and cholesterol 7α-hydroxylase in CBE-fed mice were not significantly different from controls. Dietary CBE did not alter hepatic lipid content or the hepatic expression of genes involved in lipogenesis and fatty acid ß-oxidation such as fatty acid synthase, carnitine palmitoyltransferase 1 and acyl-CoA oxidase. Plasma paraoxonase and catalase activities were significantly increased in mice fed 0.05% CBE. Both CBE diets increased hepatic glutathione peroxidase (GPx) activity but the 0.05% CBE group had 24% less proximal intestine GPx activity relative to controls. Thus, dietary CBE lowered total cholesterol and improved plasma and hepatic antioxidant function at nutritionally-relevant doses in apoE(-/-) mice. Furthermore, the CBE cholesterol-lowering mechanism in apoE(-/-) mice was independent of hepatic expression of genes involved in cholesterol metabolism.


Assuntos
Antioxidantes/metabolismo , Apolipoproteínas E/genética , Colesterol/sangue , Photinia/química , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Acil-CoA Oxidase/genética , Acil-CoA Oxidase/metabolismo , Animais , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Colesterol 7-alfa-Hidroxilase/genética , Colesterol 7-alfa-Hidroxilase/metabolismo , Cromatografia Líquida de Alta Pressão , Cinamatos/farmacologia , Dieta Hiperlipídica , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Camundongos , Camundongos Knockout , RNA Mensageiro
16.
J Agric Food Chem ; 60(49): 12151-6, 2012 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-23167850

RESUMO

Extractable and bound proanthocyanidins and hydrolyzable tannins were characterized in Nonpareil, Carmel, and Butte almond varieties from California, with n = 3 samples/variety. Bound proanthocyanidins were recovered from extracted defatted almond residue by hydrolysis with 4 N sodium hydroxide and represented 3-21% of the total proanthocyanidin content among varieties. The bound proanthocyanidins were recovered primarily as monomers and dimers. In contrast, acid hydrolysis of extracted almond residue did not yield bound proanthocyanidins. Hydrolyzable tannins were characterized in aqueous acetone extracts of defatted almond using two-dimensional TLC and further quantitated by HPLC following acid hydrolysis. Almond hydrolyzable tannin content was 54.7 ± 2.3 mg ellagic acid and 27.4 ± 7.3 mg gallic acid per 100 g almond among varieties. The tannin contents of Nonpareil, Carmel, and Butte almond varieties were not significantly different. Thus, bound proanthocyanidins and hydrolyzable tannins significantly contribute to almond polyphenol content.


Assuntos
Análise de Alimentos/métodos , Taninos Hidrolisáveis/análise , Proantocianidinas/análise , Prunus/química , California , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina/métodos , Hidrólise , Taninos Hidrolisáveis/química , Proantocianidinas/química
17.
Br J Nutr ; 108(1): 16-27, 2012 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-22018225

RESUMO

Retinal pigment epithelium (RPE) cells are vital for retinal health. However, they are susceptible to injury with ageing and exposure to excessive light, including UV (100-380 nm) and visible (380-760 nm) radiation. To evaluate the protective effect of blueberry anthocyanins on RPE cells, in vitro cell models of replicative senescent and light-induced damage were established in the present study. After purification and fractionation, blueberry anthocyanin extracts (BAE) were yielded with total anthocyanin contents of 31·0 (SD 0·5) % and were used in this study. Replicative senescence of RPE cells was induced by repeatedly passaging cells from the fourth passage to the tenth. From the fifth passage, cultured RPE cells began to enter a replicative senescence, exhibiting reduced cell proliferation along with an increase in the number of ß-galactosidase-positive cells. RPE cells maintained high cell viability (P < 0·01) and a low (P < 0·01) percentage of ß-galactosidase-positive cells when treated with 0·1 µg/ml BAE. In contrast, after exposure to 2500 (SD 500) lx light (420-800 nm) for 12 h, RPE cells in the positive control (light exposure, no BAE treatment) exhibited premature senescence, low (P < 0·01) cell viability and increased (P < 0·01) vascular endothelial growth factor (VEGF) release compared with negative control cells, which were not subjected to light irradiation and BAE exposure. Correspondingly, BAE is beneficial to RPE cells by protecting these cells against light-induced damage through the suppression of ageing and apoptosis as well as the down-regulation of the over-expressed VEGF to normal level. These results demonstrate that BAE is efficacious against senescence and light-induced damage of RPE cells.


Assuntos
Antocianinas/farmacologia , Mirtilos Azuis (Planta)/química , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/efeitos da radiação , Luz/efeitos adversos , Epitélio Pigmentado da Retina/citologia , Envelhecimento , Antocianinas/química , Linhagem Celular , Proliferação de Células , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/efeitos da radiação , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
J Agric Food Chem ; 59(18): 10277-85, 2011 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-21827150

RESUMO

Flavonoids often show inconsistent antioxidant activities (AAs) depending on the assay used. The electrochemical properties of 14 flavonoid standards in cyclic voltammetry [area under anodic wave (Q) and oxidant peak potentials (Epa)] and the structural parameters [bond dissociation enthalpy (BDE) and ionization potential (IP)] were investigated. They were compared with the results of four spectrophotometric assays, namely, diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu reagent (FCR), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), to analyze the chemical reasons for the varying AAs of flavonoids under different assays. Using the cyclic voltammetry method, the AAs of the flavonoids in the DPPH, FCR, and FRAP assays were mainly determined by the ease of charge transferring in the first oxidation step. Meanwhile, the results of TEAC assays were primarily influenced by the amount of charge transfer in the multiple oxidation steps (MOS) of flavonoids. In the theoretical calculation, the BDE values of the selected flavonoids had considerably higher correlations with the results of the DPPH assay (r2=0.89) compared with the other three assays, which indicates that the oxidant-scavenging reaction of the tested flavonoids in the DPPH assay is closer to a hydrogen atom transfer mechanism. Neither the IP values nor BDE values had satisfactory correlation with the AAs of the flavonoids in the TEAC assay (r2=0.57, r2=0.54, respectively), Therefore, complex reaction mechanisms underlie this method and appropriate structural descriptors for reflecting the AAs of flavonoids based on MOS (e.g., TEAC values) need further investigation.


Assuntos
Antioxidantes/química , Flavonoides/química , Espectrofotometria/métodos , Antioxidantes/farmacologia , Técnicas Eletroquímicas , Flavonoides/farmacologia , Oxirredução , Termodinâmica
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