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See detailAntioxidant capacity and phenolic composition of red wines from various grape varieties : specificity of pinot noir.
degives, Julien; Kevers, Claire ULg; DEFRAIGNE, Jean ULg et al

in Giuseppe Viali (Ed.) 3rd international conference on cellular environmental stressors in biology and medicine : focus on redox reactions (2014, June 25)

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See detailAntioxidant capacity and phenolic composition of red wines from various grape varieties: Specificity of Pinot Noir.
Van Leeuw, Robin; Kevers, Claire ULg; PINCEMAIL, Joël ULg 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 ▲]

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See detailAntioxidant capacity of black currant varies with organ, season, and cultivar
Tabart, Jessica; Kevers, Claire ULg; Pincemail, Joël ULg et al

in Journal of Agricultural and Food Chemistry (2006), 54(17), 6271-6276

Small berries such as black currant constitute one of the important sources of potential health-promoting phytochemicals because these fruits are rich sources of compounds with high antioxidant properties ... [more ▼]

Small berries such as black currant constitute one of the important sources of potential health-promoting phytochemicals because these fruits are rich sources of compounds with high antioxidant properties. In this work, antioxidant capacities of different parts (buds, leaves, fruits) of various black currant cultivars were compared throughout the growing season with the aim to prepare extracts with high antioxidant capacity. Buds (opened, at the end of March) and leaves (in June) had a higher content in phenolics and antioxidants than fully ripened berries (in July) and the best yield (per branch) was obtained with the leaves collected in June due to their higher biomass. The differences observed among the eight cultivars tested were small. Concerning flavonols, quercetin was dominant in all organs and cultivars, myricetin varied widely among the cultivars, and kampferol was very low. [less ▲]

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See detailAntioxidant capacity of hydrophilic food matrices: optimization and validation of ORAC assay.
Kevers, Claire ULg; Sipel, Arnaud; PINCEMAIL, Joël ULg 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 ▲]

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See detailAntioxidant capacity of small dark fruits. Influence of cultivars and harvest time
Kevers, Claire ULg; PINCEMAIL, Joël ULg; Defraigne, Jean-Olivier ULg 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 ▲]

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See detailANTIOXIDANT CAPACITY OF THREE CUBAN SPECIES OF THE GENUS Pluchea Cass. (Asteraceae)
Perera, Wilmer; Tabart, Jessica ULg; Gomez, Abel et al

in Journal of Food Biochemistry (2010), 34

Leaves of three Cuban species of the genus Pluchea: P. carolinensis, P. odorata and P. rosea were extracted with various solvents and analysed. Highest values of phenolic compounds were detected after ... [more ▼]

Leaves of three Cuban species of the genus Pluchea: P. carolinensis, P. odorata and P. rosea were extracted with various solvents and analysed. Highest values of phenolic compounds were detected after ethyl acetate (EtOAc) and n-butyl alcohol (n-BuOH) extractions. Flavonoids were detected after chloroform, EtOAc and n-BuOH extractions of the species Pluchea and three aglycone flavonol forms (quercetin, kaempferol and myricetin) were also quantified after EtOAc and n-BuOH extractions, using HPLC. The total antioxidant capacity (TAC), expressed as Trolox equivalents per gram of leaf dry weight (TE/g dw) was analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS∙+), and the oxygen radical absorbance capacity (ORAC). The highest values of TAC were detected after EtOAc and n-BuOH extractions of the three species. P. carolinensis was the promising species; being the n-BuOH extraction with the most bioactive compounds : 15.3 mg TE/g dw using DPPH∙ [less ▲]

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See detailAntioxidant Defense and Free Radical Production in a Rabbit Model of Kidney Ischemia-Reperfusion
Franssen, Colette ULg; Defraigne, Jean-Olivier ULg; Detry, Olivier ULg et al

in Transplantation Proceedings (1995), 27(5), 2880-3

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See detailAntioxidant fractions and phenolic constituents from leaves of Pluchea carolinensis and Pluchea rosea
Perera Cordoba, Wilmer Hervet; Wauters, Jean-Noël ULg; Kevers, Claire ULg et al

in Free Radicals and Antioxidants (2014), 4(2), 1-7

Abstract: Objective: To evaluated the antioxidant potential of several polar fractions of P. carolinensis and P. rosea as well as pure chemicals, some of them quantified in both species by HPLC. Methods ... [more ▼]

Abstract: Objective: To evaluated the antioxidant potential of several polar fractions of P. carolinensis and P. rosea as well as pure chemicals, some of them quantified in both species by HPLC. Methods: The antioxidant potential of polar fractions and pure chemicals were assayed by 2,2-diphenyl-1-picrylhydrazyl and oxygen radical potential methods. The phenolic content was performed by using Folin–Ciocalteu’s reagent. Specific phenolic acids and flavonoids were quantified by DAD-RP-HPLC. Results: The highest DPPH antioxidant potential expressed in mg TE/gDE were frequently measured in fractions from n-butyl alcohol i.e 2 (192.1 ± 0.3); 6 (181.0 ± 0.1) of P. carolinensis and in fraction 7 (188.1 ± 5.5) of P. rosea while for ORAC (mg TE/gDE) assay fraction 2 (543.0 ± 64.6) and 4 (501.4 ± 49.7) of P. carolinensis and 3 (401.3 ± 16.1) and 6 (401.3 ± 16.1) of P. rosea showed the best results. Some flavonoids and phenolic acids were also assayed; all of them showed highest Oxygen radical absorbance capacity values. Conclusion: We report the antioxidant potential of polar fractions, as well as of some pure phenolics responsible of the antioxidant potential. Some phenolics were identified and quantified for the first time in both species. Apparently, caffeoylquinic acid derivatives contribute more significant to the total antioxidant potential of the extracts. [less ▲]

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See detailAntioxidant phenolic extracts obtained from secondary Tunisian date varieties (Phoenix dactylifera L.) by hydrothermal treatments
Mrabet, Abdessalem ULg; Jiménez-Araujo, Ana; Fernández-Bolaños, Juan et al

in Food Chemistry (2015), 196(2016), 917-924

Three common non-commercial Tunisian date varieties were treated by two thermal systems, obtaining a liquid fraction which was characterized and its antioxidant capacity determined. The concentration of ... [more ▼]

Three common non-commercial Tunisian date varieties were treated by two thermal systems, obtaining a liquid fraction which was characterized and its antioxidant capacity determined. The concentration of total phenols in the three varieties (Smeti, Garen Gazel, and Eguwa) was increased by steam explosion treatment up to 5311, 4680, and 3832 mg/kg of fresh dates, and their antioxidant activity up to 62.5, 46.5 and 43.1 mmol Trolox®/kg of fresh date, respectively. Both thermal treatments increased the content of phenolic acids. Additionally, a long scale study was carried out in a pilot plant, with steam treatment at 140 °C and 160 °C for 30 min. The liquid phase was extracted and fractionated chromatographically using adsorbent or ionic resins. The phenolic profiles were determined for each fraction, yielding fractions with interesting antioxidant activities with EC50 values of up to 0.08 mg/L or values of TEAC of 0.67 mmol Trolox®/g of extract. [less ▲]

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See detailAntioxidant potential of different plum cultivars during storage
MIHALACHE ARION, Cristina; TABART, Jessica; Kevers, Claire ULg et al

in Food Chemistry (2013), 146

Plums, the most commonly consumed fruits from Romania, are fruit rich in bioactive compounds like antioxidants. This research work was carried out to investigate the antioxidant potential of twelve plum ... [more ▼]

Plums, the most commonly consumed fruits from Romania, are fruit rich in bioactive compounds like antioxidants. This research work was carried out to investigate the antioxidant potential of twelve plum cultivars, fresh and stored during 10 days at 4°C by using different methods (DPPH, ORAC and erythrocyte resistance to haemolysis). The contents of total phenolic compounds and total anthocyanins were also determined by specific spectrometric methods. Significant differences between fresh and stored plum cultivars (p < 0.05) were found. Storage at 4°C resulted in an increase in antioxidant potential and anthocyanins content of the autumn plum varieties. Autumn plum varieties showed also a higher antioxidant capacity than summer varieties, as assessed by the ORAC and the haemolysis resistance assays. Our results suggest that even after storage plums could be a good source of antioxidants, which may provides health-promoting effects for humans. [less ▲]

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See detailAntioxidant potentiality of three herbal teas consumed in Bandundu rural areas of Congo.
Mutwale Kapepula, Paulin ULg; Mbombo Mungitshi, Patricia; Franck, Thierry ULg et al

in Natural Product Research (2016)

The aim of this study was to evaluate and compare the cellular antioxidant activities of Lantana montevidensis, Lippia multiflora, and Ocimum gratissimum leaves often consumed as herbal teas in a rural ... [more ▼]

The aim of this study was to evaluate and compare the cellular antioxidant activities of Lantana montevidensis, Lippia multiflora, and Ocimum gratissimum leaves often consumed as herbal teas in a rural area of Bandundu severely affected by konzo, which is related to oxidative damage. Consequently, dietary supplements with proven antioxidant potentialities could be of real interest to promote in this area. Phytochemical screening by TLC and HPLC-DAD of extracts revealed the presence of verbascoside as a major phenolic compound. Verbascoside in L. montevidensis and O. gratissimum is reported here for the first time. All extracts displayed high ABTS and DPPH radical-scavenging activities at the concentration range of 1-40 mug mL-1 according to order: L. multiflora > O. gratissimum > L. montevidensis. L. multiflora showed the best cellular antioxidant activity using DCFH-DA on HL-60 monocytes assay at 1-20 mug mL-1. These herbal teas may be used as nutraceuticals for their potent antioxidant activity. [less ▲]

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See detailAntioxidant power of phytochemicals from Psidium guajava leaf.
Qian, He; Nihorimbere, Venant ULg

in Journal of Zhejiang University. Science. B (2004), 5(6), 676-683

ried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically ... [more ▼]

ried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 +/-15.5 and 511.6+/-6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH*) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH* color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC(50) and the time needed to reach the steady state to EC(50) concentration (T(EC(50))) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC(50). This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants. [less ▲]

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See detailThe antioxidant properties of non stroidal anti-inflammatory drugs
Henrotin, Yves ULg; Mouithys-Mickalad, Ange ULg; Mathy-Hartert, M et al

in Osteoarthritis and Cartilage (2000), 8

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See detailThe antioxidant responses differ between Symbiodinium strains from different geographic origins
Roberty, Stéphane ULg; Furla, Paola; Plumier, Jean-Christophe ULg

Conference (2016, June)

Studies conducted these last two decades have revealed that high sea surface temperatures accompanied by high levels of solar irradiance are responsible for an over production of reactive oxygen species ... [more ▼]

Studies conducted these last two decades have revealed that high sea surface temperatures accompanied by high levels of solar irradiance are responsible for an over production of reactive oxygen species (ROS) leading to the disruption of the symbiosis between cnidarians and their symbiotic Symbiodinium. But, all coral species do not show the same sensitivity to stress. In this context we examined how the antioxidant network of different Symbiodinium species responds to oxidative stress. We bypassed the various thermal and light tolerances existing among the genus Symbiodinium by using a chemical approach, i.e., a treatment with menadione. ROS produced during this oxidative burst reduced photosynthesis by 30 to 50% and significantly decreased the activity of superoxide dismutase. In addition, the low level of lipid peroxidation concomitantly with the decrease in the concentration of diatoxanthin and other carotenoids during the oxidative stress confirms their function of antioxidants and their role in the stabilization of membrane lipids. The analysis of the cellular damages also indicates that proteins were damaged and most likely eliminated by the ubiquitin-proteasome pathway. Finally, caspase-like activity decreased suggesting that cell death mechanisms are not initiated at the early stage of the stress. Although, the mechanisms at play seem to be the same, we found that the temperate Symbiodinium strain (A1) was less impacted by the treatment with menadione than the tropical strain (F1) suggesting that the variations observed are related to their geographic origin. [less ▲]

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See detailAntioxidant Status after Cold Ischemia of Rabbit Lung
Pincemail, Joël ULg; Kolh, Philippe ULg; Detry, Olivier ULg et al

in Transplantation Proceedings (2000), 32(2), 484-5

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See detailAntioxidant Therapy in Intensive Care
Lovat, R.; Preiser, Jean-Charles ULg

in Current Opinion in Critical Care (2003), 9(4), 266-70

PURPOSE OF REVIEW: This review intends to summarize the recent findings regarding the presence of increased oxidative stress in critically ill patients and its potential pathophysiologic role, as well as ... [more ▼]

PURPOSE OF REVIEW: This review intends to summarize the recent findings regarding the presence of increased oxidative stress in critically ill patients and its potential pathophysiologic role, as well as the results of recent clinical trials of antioxidant therapies. RECENT FINDINGS: Several lines of evidence confirm the increase in oxidative stress during critical illness. The oxidative damage to cells and tissues eventually contributes to organ failure. Prophylactic administration of antioxidant vitamins or glutamine, incorporated in the nutritional support or given as separate medications, efficiently attenuates the oxidative stress and in some studies improves the outcome of critically ill patients. Few data on the effects of N-acetylcysteine or trace elements have been published during the last two years. SUMMARY: Patients at risk of organ failure could benefit from the early adjunction of antioxidant treatment, including vitamins and glutamine. [less ▲]

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See detailAntioxidant to treat osteoarthritis: dream or reality?
Henrotin, Yves ULg; Kurz, B.

in Current Drug Targets (2007), 8(2), 347-57

Osteoarthritis is one of the most common chronic diseases that causes pain and physical disability in patient. Although OA is considered as a global disease affecting all joint tissues, cartilage ... [more ▼]

Osteoarthritis is one of the most common chronic diseases that causes pain and physical disability in patient. Although OA is considered as a global disease affecting all joint tissues, cartilage degradation is the end point. The degradation of cartilage results of the combination of mechanical stress and biochemical factors, mainly metalloproteinases and reactive oxygen species (ROS). The activity of reactive oxygen species is balanced by enzymatic and non-enzymatic antioxidants, that act by inhibiting oxidative enzymes, scavenging free radicals or chelating ion metals. Until now, few information is available on the antioxidative status of chondrocytes. Further, the modification of the antioxidative system in osteoarthritis remains unknown. Some antioxidant supplements or drugs with antioxidant properties have been developed to reinforce the cellular antioxidant status. However, until now, there is no consistent evidence that additional antioxidant supply is efficient to relieve OA symptoms or to prevent structural changes in OA cartilage. [less ▲]

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See detailAntioxidant vitamin cocktail does not improve calves'lung function and airway inflammation in ozone-induced pulmonary disease
Kirschvink, Nathalie; Jacqmot, Olivier ULg; Fievez, Laurence ULg et al

in Pflügers Archiv : European Journal of Physiology (2001), 442(R42),

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See detailAntioxidants involvement in the Ageing of Non-Green Organs
Delaplace, Pierre ULg; Fauconnier, Marie-Laure ULg; du Jardin, Patrick ULg

in Gupta, S. Dutta (Ed.) Reactive oxygen species and antioxidants in higher plants (2010)

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See detailAntioxydant activity of β-carboline derivatives in the LDL oxidation model
Hadjaz, Fariza; Besret, Soizic; Martin-Nizard, Françoise et al

in European Journal of Medicinal Chemistry (2001), 46

A series of b-carboline compounds were synthesized, starting from compound GWC22, their antioxidant activity was determined by inhibition of lipid peroxidation. The oxidation of LDL was induced in the ... [more ▼]

A series of b-carboline compounds were synthesized, starting from compound GWC22, their antioxidant activity was determined by inhibition of lipid peroxidation. The oxidation of LDL was induced in the presence of CuSO4 or 2,20-azobis(2-amidinopropane) dihydrochloride (AAPH). The protective actions of these compounds against the cytotoxicity were evaluated with lactate dehydrogenase (LDH) activity in bovine aortic endothelial cells (BAECs) and cellular vitality by measuring mitochondrial activity in the presence of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Most of compounds showed an higher antioxidant activity than GWC22 derivative (R = 1.6 for 5 mM CuSO4). The best antioxidant activities are phenolic and benzyloxy derivatives with ratio R = 1.9 to 2.8 for 1 mM CuSO4. These substances have protective actions and increase significantly the cell viability. [less ▲]

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