Antioxidant capacity and phenolic composition of red wines from various grape varieties : specificity of pinot noir.
; Kevers, Claire ; DEFRAIGNE, Jean et al
in Giuseppe Viali (Ed.) 3rd international conference on cellular environmental stressors in biology and medicine : focus on redox reactions (2014, June 25)Detailed reference viewed: 16 (3 ULg)
Is isokinetic eccentric exercise dangerous for the heart?
LE GOFF, Caroline ; Kaux, Jean-François ; LAURENT, Terry et al
in Isokinetics & Exercise Science (2014), 22(2), 131-136
BACKGROUND: Very strenuous exercises can be performed on an isokinetic dynamometer in order to evaluate the resistance to fatigue of different muscular groups. Good cardiac function is necessary in order ... [more ▼]
BACKGROUND: Very strenuous exercises can be performed on an isokinetic dynamometer in order to evaluate the resistance to fatigue of different muscular groups. Good cardiac function is necessary in order to perform these very intensive exercises; otherwise an acute myocardial dysfunction could theoretically appear in predisposed patients. OBJECTIVE: Our study aimed to observe the cardiovascular impact of a maximal intense isokinetic eccentric exercise performed by a population of sedentary young men. METHODS: Resting and post-exercise (just after, 3 hours and 24 hours after the exercise) blood samples were taken from 12 young male sedentary healthy subjects. These subjects performed an intense maximal eccentric isokinetic exercise of the quadriceps muscle.We evaluated markers of cardiovascular risk (troponin I, highly sensitive troponin T, NT-proBNP,myoglobin), of inflammation (hsCRP) and of oxidative stress (myeloperoxydase, lipidic peroxides, reduced and oxidized glutathione). RESULTS: The following observations were made: no significant increase in cardiac (NT-proBNP, troponins) or inflammation (hsCRP) biomarkers; a significant increase in myoglobin, myeloperoxidase, lipidic peroxides, oxidised glutathione just after the exercise. CONCLUSIONS: No modification in cardiac biomarkers were observed after the maximal eccentric isokinetic exercise. We were thus able to prove that the exercise could be performed without any risk to cardiac function in young sedentary subjects. However, a significant level of oxidative stress was induced by this exercise. [less ▲]Detailed reference viewed: 46 (14 ULg)
Determination of the plasma global antioxidant capacity: a critical review.
PINCEMAIL, Joël ; ; et al
in Annales de biologie clinique (2014), 72(4), 413-421
With respect to prevention of cardiovascular diseases and cancers, the healthcare professionals are more and more interested in the blood determination of antioxidants (vitamins C and E, carotenoids ... [more ▼]
With respect to prevention of cardiovascular diseases and cancers, the healthcare professionals are more and more interested in the blood determination of antioxidants (vitamins C and E, carotenoids, glutathione, ubiquinone, antioxidant enzymes). The major problem of these analysis is their elevated cost. At the request of the healthcare professionals, the laboratories of clinical biology suggest the measurement of the plasma global antioxidant capacity (GAC) as a replacement of the individual determination of all these antioxidants. The present review shows that such a test presents a large number of gaps, the major one being that it essentially reflects the plasma concentration of uric acid and proteins. On basis of nine arguments, we show that the measurement of the plasma GAC cannot be considered as an in vivo marker of oxidative stress nor lead to the prescription antioxidant complement. [less ▲]Detailed reference viewed: 6 (0 ULg)
QUELLE PLACE POUR LE STRESS OXYDANT ET LES ANTIOXYDANTS DANS LE PROCESSUS DU VIEILLISSEMENT ?
PINCEMAIL, Joël ; RICOUR, Céline ; DEFRAIGNE, Jean et al
in Revue Médicale de Liège (2014), 69Detailed reference viewed: 15 (0 ULg)
Antioxidant capacity of small dark fruits. Influence of cultivars and harvest time
Kevers, Claire ; PINCEMAIL, Joël ; Defraigne, Jean-Olivier et al
in Journal of Berry Research (2014), 4
BACKGROUND: Small dark fruits represent one of the most important sources of bioactive compounds with antioxidant capacity in the human diet. The content of health-promoting antioxidants in these fruits ... [more ▼]
BACKGROUND: Small dark fruits represent one of the most important sources of bioactive compounds with antioxidant capacity in the human diet. The content of health-promoting antioxidants in these fruits may be important information to take into account when a fruit producer has to choose which cultivar to grow. OBJECTIVE: It is important to know how antioxidant capacity and antioxidant compounds as total phenolics and ascorbic acid vary between 9 small dark fruit species and for each species among cultivars (2 to 10 per species). METHODS: The antioxidant capacity (ORAC assay), total phenolic (Folin-Ciocalteu) and ascorbic acid content were measured in 9 fruits (plums, blackcurrants, blackberries, blueberries, cherries, redcurrants, raspberries, white currants and gooseberries) / 42 cultivars harvested at maturity during their high production period. RESULTS: The comparison of the average of the various cultivars of each small fruits showed that blackcurrants had the best antioxidant capacity (with plums), the highest ascorbic acid content and the highest total phenolic content (with blackberries). The present study shows that total phenolic compounds, ascorbic acid and antioxidant capacity strongly differed between genotypes of each small dark fruits. Other parameters as harvest time, culture conditions and maturity degree at the harvest may also influence the antioxidant capacity of small fruits. CONCLUSION: Among small dark fruits, blackcurrants have high qualities. Choices of variety, harvest time and maturity degree are important for all fruits. [less ▲]Detailed reference viewed: 118 (27 ULg)
Antioxidant capacity and phenolic composition of red wines from various grape varieties: Specificity of Pinot Noir.
; Kevers, Claire ; PINCEMAIL, Joël et al
in Journal of Food Composition and Analysis (2014), 36
Wines produced from various grape varieties present different properties affecting taste and color. The hypothesis was that grape genotype could have a deep impact on wine antioxidant properties and ... [more ▼]
Wines produced from various grape varieties present different properties affecting taste and color. The hypothesis was that grape genotype could have a deep impact on wine antioxidant properties and phenolic composition. But in this study on 38 different wines of 4 main grape varieties, large variability in the levels of individual phenolic compounds as well as in antioxidant capacity was observed in each grape variety. Comparisons of the wine varieties based on their individual phenolic profile (flavonols, anthocyanidins, flavan-3-ols, phenolic acids, resveratrol…) and antioxidant capacities (ORAC, DPPH, hemolysis, ESR, total phenolics) showed limited differences. An exception was the group of wines made from the grape variety Pinot Noir, in which the range of phenolic compounds was different from the other wines: anthocyanidins (87 mg L-1, 119 to 206 mg L-1 in other grape varieties) and flavonols (17 mg L-1, 20 to 57 mg L-1in others except Primitivo) showed lower levels while flavanols (327 mg L-1, 152 to 244 mg L-1 in others) and phenolic acids (161 mg L-1, 103 to 152 mg L-1 in others) showed levels higher than in the other wines. This different profile was associated with a lower antioxidant capacity (i.e. mean ORAC value: 20988 for Pinot Noir, 27820 to 33651 for others). [less ▲]Detailed reference viewed: 64 (12 ULg)
Relationship between vasodilation capacity, antioxidant activity and phenolic content of different types of wine aging in oak barrels
; Kevers, Claire ; PINCEMAIL, Joël et al
in International Conference Wine Active Compounds 2014 (2014)Detailed reference viewed: 34 (12 ULg)
Antioxidant capacity of hydrophilic food matrices: optimization and validation of ORAC assay.
Kevers, Claire ; ; PINCEMAIL, Joël et al
in Food Analytical Methods (2014), 7
It is widely accepted that ORAC is a useful method for assessing food extracts that contain various antioxidants. The principal aim of this study was to validate the ORAC assay. We first identified ... [more ▼]
It is widely accepted that ORAC is a useful method for assessing food extracts that contain various antioxidants. The principal aim of this study was to validate the ORAC assay. We first identified parameters that can interfere with the ORAC assay and we optimized it. Then, experiments were conducted to determine the limits of linearity and response function, to determine the accuracy profiles to circumvent some of the drawbacks of traditional validation procedures. Trueness, selectivity and limits of quantification of the method were also determined. Our objective of ORAC method validation is thus to give guarantees that most of the results generated during use of this method will be close enough to unknown true value of antioxidant capacity of food matrices. The validation results indicate that the described method will give accurate and reliable results for Trolox equivalent values ranging from 50 to 200 µmol/L. [less ▲]Detailed reference viewed: 47 (14 ULg)
Deriving a global antioxidant score for commercial juices by multivariate graphical and scoring techniques: applications to blackcurrant juice
; Kevers, Claire ; Dardenne, Nadia et al
in Preedy (Ed.) Processing and Impact on Antioxidants in Beverages (2014)
Blackcurrants constitute an important source of potential health promoting phytochemicals (e.g. phenolic compounds, ascorbic acid) due to their antioxidant properties. Only small portions of berries are ... [more ▼]
Blackcurrants constitute an important source of potential health promoting phytochemicals (e.g. phenolic compounds, ascorbic acid) due to their antioxidant properties. Only small portions of berries are consumed fresh, most of their intake coming from processed foods, such as juices. Seven techniques were used to measure antioxidant capacity and antioxidant compounds of 10 juices. This yielded a large disparity of results. No single test, even the most popular ORAC assay, is able to compare the antioxidant capacity of similar food matrix such as blackcurrant juices. By combining tests from a large battery of « antioxidant » assays, it is possible to improve the discrimination of a food matrix by establishing a Global Antioxidant Score (GAS) which correlates well with graphical representations like Chernoff faces or stars. The latter approaches may help food industry managers and authorities to compare their « antioxidant » products with those existing on the market. [less ▲]Detailed reference viewed: 61 (23 ULg)
CLINICAL AND FUNCTIONAL CHARACTERISTICS OF NONAGENARIANS HOSPITALIZED IN A GERIATRIC UNIT: A DESCRIPTIVE STUDY
Petermans, Jean ; ; ALLEPAERTS, Sophie et al
in Journal of Aging Research and Clinical Practice (2013), 2(3), 303-309Detailed reference viewed: 61 (17 ULg)
Fatty acids and associated cardiovascular risk
LE GOFF, Caroline ; Kaux, Jean-François ; et al
in Food and Nutrition Sciences (2013), 4(9A), 188-194
Background: A fatty acid (FA) is a carboxylic acid with a long aliphatic chain, which is either saturated or unsaturated. Recently, the role of FA and particularly omega-3 and -6 has emerged as ... [more ▼]
Background: A fatty acid (FA) is a carboxylic acid with a long aliphatic chain, which is either saturated or unsaturated. Recently, the role of FA and particularly omega-3 and -6 has emerged as cardiovascular risk factor in the literature. The aim of our study was to establish reference values for these FA and to compare them with data obtained in a population of acute myocardial infarction (AMI) patients. Materials and methods: Hundred thirty five healthy subjects (59.38 ± 27.12 yo, 75 men) were selected as reference population. We also evaluated FA in thirty three patients (55 ± 9 yo, 23 men) admitted in the Emergency Department of our Institution for AMI. The fasting whole blood was drawn in vacutainer containing EDTA. Before analysis, samples were washed and transmethylated. We performed the quantification of different FA by gas chromatography associated with flame ionisation detector (GCFID). Results: We obtained results in control healthy patients to be used as reference values. In the AMI group, levels of omega-6 were significantly higher (p<0.05) for C18:2n6 and C18:3n6 than the reference population and omega-3 values were significantly lower (p<0.01) compared to reference value for C22:6n3. The omega-3 index was lower and the ratio omega-6/omega-3 was higher in AMI group compared to reference values. Conclusions: We have established reference value for FA and have compared these values with the results obtained in AMI population. FA determination is a new tool we are able to use and to process in our laboratory which can help the clinician to screen patients with the highest cardiovascular risks because of the implication of FA in the etiopathogeny of atherosclerosis. [less ▲]Detailed reference viewed: 23 (10 ULg)
Factors likely to contribute to post-operative delirium. The cascade study, confusion after surgical cardiac intervention developed
ALLEPAERTS, Sophie ; PINCEMAIL, Joël ; Defraigne, Jean-Olivier et al
Poster (2013)Detailed reference viewed: 23 (6 ULg)
On the Potential Effect of Increased Dietary Intake of Fruits and Vegetables on Biomarkers of Lipid Peroxidation in Type 2 Diabetes Patients
PINCEMAIL, Joël ; PAQUOT, Nicolas ; et al
in Journal of Pharmacy & Nutrition Sciences (2013), 3(3),Detailed reference viewed: 20 (9 ULg)
Sample dilution influences the determination of antioxidant capacity in food. How to minimize it?
; Kevers, Claire ; PINCEMAIL, Joël et al
in Food Analytical Methods (2013), 6(5), 1485-1491
The influence of sample dilution on the measurement of antioxidant capacity was analyzed. To ensure the reproducibility of results it is necessary to realize such scarce investigations. This study focuses ... [more ▼]
The influence of sample dilution on the measurement of antioxidant capacity was analyzed. To ensure the reproducibility of results it is necessary to realize such scarce investigations. This study focuses on different antioxidant capacity assays, commonly used for the analysis of pure substances and food extracts. For all compounds and foods tested in most of the four assays (TEAC, DPPH and ORAC), effects of sample dilution on the measured (and recalculated) antioxidant capacity were observed, differences up to 28% between dilutions. An extrapolation method was proposed to obtain a “real value” thus to minimize the effects of the sample dilution. This extrapolation method is relatively simple, based on a linear regression of 4 or 5 appropriate dilutions of the sample and applicable to the various assays. The use of such a method will improve the consistency of inter-laboratory antioxidant capacity data and thus permit better comparisons. In contrast, there was no dilution problem with FRAP assays. [less ▲]Detailed reference viewed: 53 (11 ULg)
Extraction conditions can greatly influence antioxidant capacity assays in plant food matrices
Michiels, Jean-Albert ; Kevers, Claire ; Pincemail, Joël et al
in Food Chemistry (2012), 130
The estimated antioxidant capacity of different matrices can vary considerably between research reports. Besides intrinsic factors (not studied here), our work showed that may have various causes. Firstly ... [more ▼]
The estimated antioxidant capacity of different matrices can vary considerably between research reports. Besides intrinsic factors (not studied here), our work showed that may have various causes. Firstly, different methods are used to measure antioxidant capacity. Secondly, the results obtained for a single matrix by one method (such as ORAC) can vary with the extraction conditions. Parameters having a great impact on the amount and composition of antioxidants in extracts, and thus on the measured antioxidant capacity, notably include the extraction solvent composition, temperature, extraction time (duration), solvent-to-solid ratio, and storage conditions. Standardization of the extraction procedure is thus necessary for accurate and reproducible determination of the antioxidant capacity and phenolics in different food matrices by different laboratories. In this study we optimised such a procedure for four fresh plant matrices (orange, apple, leek, and broccoli). The optimised procedure requires extraction in a mixture of acetone/water/acetic acid (70/28/2, v/v/v) for 1 h at 4°C, with a solvent-to-solid ratio of 20 mL per 1 g. Fresh material should be used, but if this is not possible, one may lyophilise the plant matrices or store the extracts for a few days at -20°C before analysis. [less ▲]Detailed reference viewed: 194 (16 ULg)
On the potential increase of the oxidative stress status in patients with abdominal aortic aneurysm.
PINCEMAIL, Joël ; Defraigne, Jean-Olivier ; et al
in Redox Report : Communications in Free Radical Research (2012), 17(4), 139-44
BACKGROUND: Abdominal aortic aneurysm (AAA) is a major cause of preventable deaths in older patients. Oxidative stress has been suggested to play a key role in the pathogenesis of AAA. However, only few ... [more ▼]
BACKGROUND: Abdominal aortic aneurysm (AAA) is a major cause of preventable deaths in older patients. Oxidative stress has been suggested to play a key role in the pathogenesis of AAA. However, only few studies have been conducted to evaluate the blood oxidative stress status of AAA patients. METHODS AND RESULTS: Twenty seven AAA patients (mean age of 70 years) divided into two groups according to AAA size (</= 50 or > 50 mm) were compared with an age-matched group of 18 healthy subjects. Antioxidants (vitamins C and E, beta-carotene, glutathione, thiols, and ubiquinone), trace elements (selenium, copper, zinc, and copper/zinc ratio) and markers of oxidative damage to lipids (lipid peroxides, antibodies against oxidized patients, and isoprostanes) were measured in each subject. The comparison of the three groups by ordinal logistic regression showed a significant decrease of the plasma levels of vitamin C (P = 0.011), alpha-tocopherol (P = 0.016) but not when corrected for cholesterol values, beta-carotene (P = 0.0096), ubiquinone (P = 0.014), zinc (P = 0.0035), and of selenium (P = 0.0038), as AAA size increased. By contrast, specific markers of lipid peroxidation such as the Cu/Zn ratio (P = 0.046) and to a lesser extent isoprostanes (P = 0.052) increased. CONCLUSION: The present study emphasizes the potential role of the oxidative stress in AAA disease and suggests that an antioxidant therapy could be of interest to delay AAA progression. [less ▲]Detailed reference viewed: 29 (11 ULg)
Antioxidant and anti-inflammatory activities of Ribes nigrum extracts.
Tabart, Jessica ; Franck, Thierry ; Kevers, Claire et al
in Food Chemistry (2012), 131(4), 1116-1122
Blackcurrant berries contain high amounts of flavonoids with various health benefits as anti-inflammatory properties attributed to their antioxidant potential. Leaves and buds actually used to produce ... [more ▼]
Blackcurrant berries contain high amounts of flavonoids with various health benefits as anti-inflammatory properties attributed to their antioxidant potential. Leaves and buds actually used to produce food supplement could also exhibit such interesting properties. <br />In the literature, various methods are often used and valid indicators of the antioxidant potential of dietary substances. However these assays do not provide evidence that antioxidants have in vivo or ex vivo activity when consumed. To obtain biologically relevant information, the antioxidant activities of the extracts were evaluated on cellular models implicating the measurement of blood haemolysis, the Cellular Antioxidant Activity on endothelial cells and the anti-inflammatory activities on isolated equine stimulated neutrophils and purified myeloperoxidase. <br />These tests generally showed that the blackcurrant leaf extract have the highest antioxidant and <br />anti-inflammatory (inhibition of MPO activity and ROS production on activated neutrophils) capacities correlated to the highest total phenolics content. [less ▲]Detailed reference viewed: 189 (42 ULg)
Functional muscle impairment in facioscapulohumeral muscular dystrophy is correlated with oxidative stress and mitochondrial dysfunction.
; ; et al
in Free Radical Biology & Medicine (2012), 53(5), 1068-79
Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms ... [more ▼]
Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms, legs, and trunk. FSHD is genetically linked to contractions of the D4Z4 repeat array causing activation of several genes. One of these maps in the repeat itself and expresses the DUX4 (the double homeobox 4) transcription factor causing a gene deregulation cascade. In addition, analyses of the RNA or protein expression profiles in muscle have indicated deregulations in the oxidative stress response. Since oxidative stress affects peripheral muscle function, we investigated mitochondrial function and oxidative stress in skeletal muscle biopsies and blood samples from patients with FSHD and age-matched healthy controls, and evaluated their association with physical performances. We show that specifically, oxidative stress (lipid peroxidation and protein carbonylation), oxidative damage (lipofuscin accumulation), and antioxidant enzymes (catalase, copper-zinc-dependent superoxide dismutase, and glutathione reductase) were higher in FSHD than in control muscles. FSHD muscles also presented abnormal mitochondrial function (decreased cytochrome c oxidase activity and reduced ATP synthesis). In addition, the ratio between reduced (GSH) and oxidized glutathione (GSSG) was strongly decreased in all FSHD blood samples as a consequence of GSSG accumulation. Patients with FSHD also had reduced systemic antioxidative response molecules, such as low levels of zinc (a SOD cofactor), selenium (a GPx cofactor involved in the elimination of lipid peroxides), and vitamin C. Half of them had a low ratio of gamma/alpha tocopherol and higher ferritin concentrations. Both systemic oxidative stress and mitochondrial dysfunction were correlated with functional muscle impairment. Mitochondrial ATP production was significantly correlated with both quadriceps endurance (T(LimQ)) and maximal voluntary contraction (MVC(Q)) values (rho=0.79, P=0.003; rho=0.62, P=0.05, respectively). The plasma concentration of oxidized glutathione was negatively correlated with the T(LimQ), MVC(Q) values, and the 2-min walk distance (MWT) values (rho=-0.60, P=0.03; rho=-0.56, P=0.04; rho=-0.93, P<0.0001, respectively). Our data characterized oxidative stress in patients with FSHD and demonstrated a correlation with their peripheral skeletal muscle dysfunction. They suggest that antioxidants that might modulate or delay oxidative insult may be useful in maintaining FSHD muscle functions. [less ▲]Detailed reference viewed: 51 (0 ULg)