Josep Valls

University of Bordeaux, Bordeaux, Aquitaine, France

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Publications (13)35.5 Total impact

  • Article: Bioavailability of procyanidin dimers and trimers and matrix food effects in in vitro and in vivo models - CORRIGENDUM.
    The British journal of nutrition 03/2013; · 3.45 Impact Factor
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    Article: Phenolic compounds and somatic embryogenesis in cotton (Gossypium hirsutum L.)
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    ABSTRACT: Studies of phenolic compounds were performed during cell suspension cultures in relation with the induction of embryogenic structures in two cultivars of cotton. Coker 312 produced embryogenic structures, unlike R405-2000 which was found to be a non-embryogenic cultivar. Embryogenesis induction in Coker 312 was strongly linked to a higher content of caffeic, ferulic and salicylic acids and to the appearance of p-coumaric acid, benzoic acid, trans-resveratrol, catechin and naringenin.
    Plant Cell Tissue and Organ Culture 04/2012; 90(1):25-29. · 3.09 Impact Factor
  • Article: Toxicology evaluation of a procyanidin-rich extract from grape skins and seeds.
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    ABSTRACT: The procyanidin-rich extract from grape seeds and skins (GSSE) has antioxidant properties which may have cardioprotective effects. Since it might be interesting to incorporate this extract into a functional food, toxicological tests need to be made to determine how safe it is. In this study we carried out a limit test to determine the acute oral toxicity and the lethal dose 50 (LD50) and some genotoxicity tests of the extract in rats. The LD50 was higher than 5000 mg/kg. Doses of up to 2000 mg/kg showed no increase in micronucleated erythrocytes 72 h after treatment. The bacterial reverse mutation test showed that the extract was weakly mutagenic to the dose of 5 mg/plate and 19.5 and 9.7 μg/ml of GSSE did not show significant differences in the frequency of aberrant metaphases in relation to negative controls. Our results indicated slight mutagenicity under the study conditions, so further studies should be conducted at lower doses to demonstrate that this extract is not toxic.
    Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 03/2011; 49(6):1450-4. · 2.99 Impact Factor
  • Article: Rapid analysis of procyanidins and anthocyanins in plasma by microelution SPE and ultra-HPLC.
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    ABSTRACT: In the analysis of biological samples, such as plasma or serum, the quantity of sample available is a critical parameter in most cases. A good approach is the use of the microelution SPE (μSPE) plates as sample pre-treatment technique in which the loaded sample volume is low. An off-line μSPE and ultra-performance LC-ESI-MS/MS (UPLC-ESI-MS/MS) method was developed and validated to determine procyanidins and anthocyanins in spiked plasma samples. The sample pre-treatment μSPE allowed the simultaneous determination of procyanidins and anthocyanins from plasma by using a small sample volume (350 μL) and without an evaporation step previous to the chromatographic analysis. Moreover, the use of UPLC technique allowed to determine the studied compounds at low concentration levels in a short analysis time (12.5 min approximately). Then, the developed method was applied to determine the studied compounds, procyanidins and anthocyanins, and their metabolites in rat plasma samples. Previously, the rats had consumed 5000 mg/kg of a grape pomace extract and the plasma was extracted 4 h after administration. The procyanidins catechin and epicatechin glucuronide, methyl catechin and epicatechin glucuronide, and methyl catechin and epicatechin sulphate were detected at μM concentration level, and the parent anthocyanins at nM.
    Journal of Separation Science 09/2010; 33(17-18):2841-53. · 2.73 Impact Factor
  • Article: Bioavailability of procyanidin dimers and trimers and matrix food effects in in vitro and in vivo models.
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    ABSTRACT: Among procyanidins (PC), monomers, such as catechin and epicatechin, have been widely studied, whereas dimer and trimer oligomers have received much less attention, despite their abundance in our diet. Recent studies have showed that as dimers and trimers could be important in determining the biological effects of procyanidin-rich food, understanding their bioavailability and metabolism is fundamental. The purpose of the present work is to study the stability of PC under digestion conditions, the metabolism and the bioavailability by using a combination of in vitro and in vivo models. Simultaneously, the matrix effect of a carbohydrate-rich food on the digestibility and bioavailability of PC is investigated. The results show a high level of stability of PC under gastric and duodenal digestion conditions. However, the pharmacokinetic study revealed limited absorption. Free forms of dimers and trimers have been detected in rat plasma, reaching the maximum concentration 1 h after oral intake of a grape seed extract.
    The British journal of nutrition 12/2009; 103(7):944-52. · 3.45 Impact Factor
  • Article: Advanced separation methods of food anthocyanins, isoflavones and flavanols.
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    ABSTRACT: In recent years, increasing knowledge of the positive health effects of food polyphenols has prompted the need to develop new separation techniques for their extraction, fractionation and analysis. This article provides an updated and exhaustive review of the application of counter-current chromatography, high performance liquid chromatography, capillary electrophoresis, and their hyphenation with mass spectrometry to the study of food polyphenols. Flavonoids constitute the largest class of polyphenols, widely spread in the plant kingdom and common in human diet which has been the most widely studied with respect to their antioxidant and biological activities. The main subgroups are anthocyanins, catechins, isoflavones, flavonols and flavones. They are reported to exhibit antioxidant, anti-carcinogenic, anti-inflammatory, anti-atherogenic, anti-thrombotic, and immune modulating functions, among others. Since red fruit anthocyanins, soy isoflavones and flavanols from grapes and teas are currently the most used phenolic compounds for producing new nutraceuticals and functional foods, this review is focused on these three flavonoid groups.
    Journal of chromatography. A 08/2009; 1216(43):7143-72. · 4.19 Impact Factor
  • Article: A trimer plus a dimer-gallate reproduce the bioactivity described for an extract of grape seed procyanidins
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    ABSTRACT: The relationship between grape seed-derived procyanidin extract components and their bioactivity was explored. The monomeric and dimeric structures only acted as anti-inflammatory agents. Similarly, pure C1 trimer was highly effective on LPS-activated macrophages. To reproduce all of the bioactivities of the total extract, a fraction enriched with trimeric structures was needed. This trimeric-enriched fraction was divided into subfractions, the most bioactive of which contained two compounds with a molecular weight equal to a trimer (865) and a dimer-gallate (729), according to spectrometric analysis. Thus, it may be concluded that a mixture of both molecules reproduces the bioactivity in glucose metabolism (3T3-L1), lipid metabolism (HepG2) and macrophage functionality (RAW 264.6).
    Food Chemistry 01/2009; 116(1-DOI: 10.1016/j.foodchem.2009.02.044):265-270. · 3.65 Impact Factor
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    Article: Relaxation induced by red wine polyphenolic compounds in rat pulmonary arteries: lack of inhibition by NO-synthase inhibitor.
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    ABSTRACT: Some red wine polyphenols exert nitric oxide (NO)-dependent relaxation in systemic arteries, following activation of endothelial NO synthase (eNOS). In this study, the effect of red wine polyphenols was determined in rat intrapulmonary arteries, and the effect of some of these compounds was compared with the responses obtained in rat aorta. In pulmonary arteries, red wine polyphenolic extract (> 300 microg/mL) exerted relaxation that was not inhibited by the NOS inhibitor N(omega)-nitro-L-arginine methylester (L-NAME) or endothelium removal. Among the several fractions obtained from the extract, the one enriched with anthocyanins was less active than fractions containing non-anthocyanins. Among the latter, the most active for relaxing pulmonary arteries was the one enriched in the stilbene derivative trans-resveratrol (relaxation for concentration >10 microg/mL). Trans-piceid, the glucoside derivative of trans-resveratrol, was almost inactive. Trans-resveratrol-induced relaxation, as well as relaxation to the anthocyanin delphinidin, was L-NAME-insensitive in pulmonary arteries. In aorta, trans-resveratrol and trans-piceid exerted similar effects to those in pulmonary arteries that were also not inhibited by L-NAME. However, red wine polyphenolic extract and delphinidin induced relaxation of aorta at much lower concentrations (about 10 microg/mL) than in pulmonary arteries, and their effects were inhibited by L-NAME. These data show differences between small intrapulmonary arteries and systemic conductance arteries in their responses to red wine polyphenols, the major difference being that the relaxant effect of these compounds is not blunted by NOS inhibitor in pulmonary arteries. They suggest that red wine polyphenols act directly on smooth muscle to promote pulmonary artery relaxation.
    Fundamental and Clinical Pharmacology 02/2008; 22(1):25-35. · 1.80 Impact Factor
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    Article: New polyphenols active on beta-amyloid aggregation.
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    ABSTRACT: New polyphenol classes have been tested against amyloid-beta peptide aggregation. We have identified four novel polyphenols which could be efficient fibril inhibitors in Alzheimer's disease: malvidin and its glucoside and curculigosides B and D. We suggest that molecules with the particular C(6)-linkers-C(6) structure could be potent inhibitors. From the results reported for the flavan-3-ol family, their anti-amyloidogenic effects against whole peptides (1-40 and 1-42) could involve several binding sites.
    Bioorganic & medicinal chemistry letters 02/2008; 18(2):828-31. · 2.65 Impact Factor
  • Article: Grape-seed procyanidins act as antiinflammatory agents in endotoxin-stimulated RAW 264.7 macrophages by inhibiting NFkB signaling pathway.
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    ABSTRACT: Procyanindin extract (PE) is a mixture of polyphenols, mainly procyanidins, obtained from grape seed with putative antiinflammatory activity. We evaluated the PE effect on RAW 264.7 macrophages stimulated with lipopolysaccharide plus interferon-gamma that show a rapid enhanced production of prostaglandin E2 (PGE2) and nitric oxide (NO). Our results demonstrated that PE significantly inhibited the overproduction of NO, dose and time dependently. PE caused a marked inhibition of PGE2 synthesis when administered during activation. Moreover, PE pretreatment diminished iNOS mRNA and protein amount dose dependently (10-65 microg/mL). PE (65 microg/mL) pretreatment inhibited NFkappaB (p65) translocation to nucleus by nearly 40%. Trimeric and longer oligomeric-rich procyanidin fractions from PE (5-30 microg/mL) inhibited iNOS expression but not the monomeric forms catechin and epicatechin. Thus, we show that the degree of polymerization is important in determining procyanidin effects. PE was considerably a more effective inhibitor of NO biosynthesis (IC50 = 50 microg/mL) in comparison to other antiinflammatories, such as aspirin (3 mM), indomethacin (20 microM), and dexamethasone (9 nM). In conclusion, PE modulates inflammatory response in activated macrophages by the inhibition of NO and PGE2 production, suppression of iNOS expression, and NFkB translocation. These results demonstrate an immunomodulatory role of grape seed procyanidins and thus a potential health-benefit in inflammatory conditions that exert an overproduction of NO and PGE2.
    Journal of Agricultural and Food Chemistry 06/2007; 55(11):4357-65. · 2.82 Impact Factor
  • Article: Two new benzylbenzoate glucosides from Curculigo orchioides.
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    ABSTRACT: An extract from in vitro cultures of Curculigo orchioides grown as bulbils in shake flasks, afforded two new glucosides of substituted benzylbenzoate - curculigoside C (3) and curculigoside D (4) - together with two known compounds - curculigoside A (1) and curculigoside B (2). Their structures were elucidated on the basis of spectral evidence, in particular by using 2D NMR methods. Their vasoactive properties were assessed in isolated rat aortic rings.
    Fitoterapia 10/2006; 77(6):416-9. · 1.85 Impact Factor
  • Article: Determination of stilbenes (delta-viniferin, trans-astringin, trans-piceid, cis- and trans-resveratrol, epsilon-viniferin) in Brazilian wines.
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    ABSTRACT: Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Stilbenes have been shown to protect lipoproteins from oxidative damage and to have cancer chemopreventive activity. We describe a method for the direct determination of stilbenes in several red wines using high-performance liquid chromatography with UV detection. In a survey of 12 commercial wines from the south of Brazil (Rio Grande del Sul), levels of delta-viniferin are reported for the first time in different varieties of red wines. Brazilian red wine contains trans-astringin, trans-piceid, trans-resveratrol, cis-resveratrol (in high quantity: 5 times more than the trans form), epsilon-viniferin, and a compound isolated for the first time in wine, trans-delta-viniferin. Isolation and identification of delta-viniferin was achieved by NMR after extraction and fractionation of red wine phenolics. delta-Viniferin contributes, as well as cis-resveratrol and trans-piceid, to a significant proportion of stilbenes in wine dietary intake, particularly with Merlot varieties containing an average level of 10 mg/L for delta-viniferin, 15 mg/L for cis-resveratrol, and 13 mg/L for trans-piceid. The total stilbene intake from wine origin was estimated for the Brazilian population as 5.3 mg/day per person (on the basis of a regular wine consumption of 160 mL/day). delta-Viniferin can contribute to around 20% of total stilbenes in wine (average of 6.4 mg/L in red Brazilian wines). It would be important in the future to investigate the origins of the differences in wine stilbene levels in relation to the vine varieties, and the bioavailability of the newly extracted stilbene delta-viniferin in plasma after consumption of different types of wines.
    Journal of Agricultural and Food Chemistry 08/2005; 53(14):5664-9. · 2.82 Impact Factor
  • Article: Determination of Stilbenes ([delta]-viniferin, trans-astringin, trans-piceid, cis- and trans-resveratrol, [epsilon]-viniferin) in Brazilian Wines
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    ABSTRACT: Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Stilbenes have been shown to protect lipoproteins from oxidative damage and to have cancer chemopreventive activity. We describe a method for the direct determination of stilbenes in several red wines using high-performance liquid chromatography with UV detection. In a survey of 12 commercial wines from the south of Brazil (Rio Grande del Sul), levels of δ-viniferin are reported for the first time in different varieties of red wines. Brazilian red wine contains trans-astringin, trans-piceid, trans-resveratrol, cis-resveratrol (in high quantity: 5 times more than the trans form), ε-viniferin, and a compound isolated for the first time in wine, trans-δ-viniferin. Isolation and identification of δ-viniferin was achieved by NMR after extraction and fractionation of red wine phenolics. δ-Viniferin contributes, as well as cis-resveratrol and trans-piceid, to a significant proportion of stilbenes in wine dietary intake, particularly with Merlot varieties containing an average level of 10 mg/L for δ-viniferin, 15 mg/L for cis-resveratrol, and 13 mg/L for trans-piceid. The total stilbene intake from wine origin was estimated for the Brazilian population as 5.3 mg/day per person (on the basis of a regular wine consumption of 160 mL/day). δ-Viniferin can contribute to around 20% of total stilbenes in wine (average of 6.4 mg/L in red Brazilian wines). It would be important in the future to investigate the origins of the differences in wine stilbene levels in relation to the vine varieties, and the bioavailability of the newly extracted stilbene δ-viniferin in plasma after consumption of different types of wines. Keywords: Brazilian red wine; varieties; stilbenes; ε-viniferin; δ-viniferin; cis- and trans-resveratrol; trans-piceid; NMR; HPLC−UV
    06/2005;