Publications by authors named "Claire Dufour"

37 Publications

Advanced characterization of polyphenols from Myrciaria jaboticaba peel and lipid protection in in vitro gastrointestinal digestion.

Food Chem 2021 Oct 27;359:129959. Epub 2021 Apr 27.

INRAE, Avignon University, UMR408 SQPOV, F-84000 Avignon, France. Electronic address:

Ultrasound-assisted and solvent extractions resulted in similar levels of hydrolyzable tannins (10.3-6.0 mg/g), anthocyanins (7.8-10.2 mg/g) and flavonols (0.24-0.32 mg/g) for dried Myrciaria jaboticaba peel (DJP). Ultrasound was efficient for the extraction of poorly soluble hydrolyzable tannins but affected the stability of anthocyanins and flavonols. UPLC-DAD-MS allowed the identification of 44 hydrolyzable tannins as single and mixed hexosides bearing galloyl, HHDP and tergalloyl units. Twelve mixed HHDP-galloylgluconic acids and tergalloylated hexosides were newly discovered in this work. Acid hydrolysis of both ultrasonic extract and DJP yielded five major compounds, i.e. gallic acid, ellagic acid, gallic acid-C-hexoside, valoneic acid dilactone and sanguisorbic acid dilactone and pointed to higher contents in hydrolyzable tannins than by summing individual polyphenols after UPLC. Last, cyanidin-3-O-glucoside and hydrolyzable tannins from the ultrasonic extract inhibited lipid peroxidation of a Western type meal in in vitro digestion, suggesting a health benefit for these jabuticaba polyphenols.
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http://dx.doi.org/10.1016/j.foodchem.2021.129959DOI Listing
October 2021

Digestive n-6 Lipid Oxidation, a Key Trigger of Vascular Dysfunction and Atherosclerosis in the Western Diet: Protective Effects of Apple Polyphenols.

Mol Nutr Food Res 2021 03 2;65(6):e2000487. Epub 2021 Feb 2.

EA4278 LaPEC, Laboratory of Cardiovascular Pharm-ecology, Avignon University, Avignon, F-84000, France.

Scope: A main risk factor of atherosclerosis is a Western diet (WD) rich in n-6 polyunsaturated fatty acids (PUFAs) sensitive to oxidation. Their oxidation can be initiated by heme iron of red meat leading to the formation of 4-hydroxy-2-nonenal (4-HNE), a cytotoxic aldehyde. An increased 4-HNE production is implicated in endothelial dysfunction and atherosclerosis. By contrast, a diet rich in proanthocyanidins reduces oxidative stress and arterial diseases. This study evaluates the effects of a WD on vascular integrity in ApolipoproteinE (ApoE ) mice and the protective capacity of apple extract and puree rich in antioxidant proanthocyanidins.

Methods And Results: ApoE mice are fed during 12 weeks with a WD with or without n-6 PUFAs. Moreover, two WD + n-6 PUFAs groups are supplemented with apple puree or phenolic extract. An increase in digestive 4-HNE production associated with a rise in plasmatic 4-HNE and oxidized LDL concentrations is reported. Oxidizable n-6 PUFAs consumption is associated with a worsened endothelial dysfunction and atherosclerosis. Interestingly, supplementations with apple polyphenol extract or puree prevented these impairments while reducing oxidative stress.

Conclusion: n-6 lipid oxidation during digestion may be a key factor of vascular impairments. Nevertheless, an antioxidant strategy can limit 4-HNE formation during digestion and thus durably protect vascular function.
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http://dx.doi.org/10.1002/mnfr.202000487DOI Listing
March 2021

Cuticular waxes of nectarines during fruit development in relation to surface conductance and susceptibility to Monilinia laxa.

J Exp Bot 2020 09;71(18):5521-5537

INRAE, GAFL, Montfavet, France.

The cuticle is composed of cutin and cuticular waxes, and it is the first protective barrier to abiotic and biotic stresses in fruit. In this study, we analysed the composition of and changes in cuticular waxes during fruit development in nectarine (Prunus persica L. Batsch) cultivars, in parallel with their conductance and their susceptibility to Monilinia laxa. The nectarine waxes were composed of triterpenoids, mostly ursolic and oleanolic acids, phytosterols, and very-long-chain aliphatics. In addition, we detected phenolic compounds that were esterified with sugars or with triterpenoids, which are newly described in cuticular waxes. We quantified 42 compounds and found that they changed markedly during fruit development, with an intense accumulation of triterpenoids during initial fruit growth followed by their decrease at the end of endocarp lignification and a final increase in very-long-chain alkanes and hydroxylated triterpenoids until maturity. The surface conductance and susceptibility to Monilinia decreased sharply at the beginning of endocarp lignification, suggesting that triterpenoid deposition could play a major role in regulating fruit permeability and susceptibility to brown rot. Our results provide new insights into the composition of cuticular waxes of nectarines and their changes during fruit development, opening new avenues of research to explore brown rot resistance factors in stone fruit.
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http://dx.doi.org/10.1093/jxb/eraa284DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7501825PMC
September 2020

Effects of the apple matrix on the postprandial bioavailability of flavan-3-ols and nutrigenomic response of apple polyphenols in minipigs challenged with a high fat meal.

Food Funct 2020 Jun;11(6):5077-5090

Université Clermont Auvergne, INRAE, UNH, Clermont-Ferrand, France.

Food matrix interactions with polyphenols can affect their bioavailability and as a consequence may modulate their biological effects. The aim of this study was to determine if the matrix and its processing would modulate the bioavailability and the postprandial nutrigenomic response to a dietary inflammatory stress of apple flavan-3-ol monomers. We carried out an acute randomized controlled study in minipigs challenged with a high fat meal (HFM) supplemented with raw fruit, puree, or apple phenolic extract with matched content of flavan-3-ol monomers. Fasting and postprandial blood samples were collected over 3 h to quantify flavan-3-ol monomers in sera by UPLC-Q-TOF/MS and to isolate peripheral blood mononuclear cells (PBMCs) for assessing the changes in the gene expression profile using a microarray analysis. When compared to the extract-supplemented meal, the peak of the total flavan-3-ol concentration was reduced by half with both raw apple and puree supplements. The apple matrices also affected the gene expression profile as revealed by the Principal Component Analysis of the microarray data from PBMCs which discriminated the supplementation of HFM with the polyphenol extract from those with raw apples or puree. A total of 309 genes were identified as differentially expressed by the apple-derived products compared to HFM, with 63% modulated only in the presence of the food matrix (apple and puree). The number of differentially modulated genes was higher with the puree (246) than with the unprocessed apple (182). Pathway enrichment analyses revealed that genes affected by the apple-derived products control inflammation and leukocyte transendothelial migration both involved in the onset of atherosclerotic processes. Overall, this study showed that the two apple matrices reduce the postprandial serum concentration of flavon-3-ols whereas they increase the nutrigenomic response of PBMCs. The biological processes identified as modulated by the apple products suggest an attenuation of the transient pro-inflammatory response induced by a HFM. The differences observed between the nutrigenomic responses support that the apple matrix and its processing affect the nutrigenomic response, probably by increasing the bioavailability of other apple phytochemicals. To conclude, this study raises awareness for considering the impact of the food matrix and its processing on the biological response of polyphenols in nutritional studies.
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http://dx.doi.org/10.1039/d0fo00346hDOI Listing
June 2020

Recent biological invasion shapes species recognition and aggressive behaviour in a native species: A behavioural experiment using robots in the field.

J Anim Ecol 2020 07 11;89(7):1604-1614. Epub 2020 Apr 11.

Department of Biology, Washington University, St. Louis, MO, USA.

Invasive species are a world-wide threat to biodiversity. Yet, our understanding of biological invasions remains incomplete, partly due to the difficulty of tracking and studying behavioural interactions in recently created species interactions. We tested whether the interactions between the recently introduced invasive lizard Anolis cristatellus and the native Anolis oculatus in Dominica have led to changes in species recognition and aggressive behaviour of the native species. The use of realistic robots allowed us to test the behavioural response of 131 A. oculatus males towards relevant and controlled conspecific versus heterospecific stimuli, directly in the field and in two contexts (allopatry vs. sympatry). Our results show that species recognition evolved prior to sympatry in A. oculatus. Moreover, interspecific competition resulted in an increase in the time spent displaying and a divergence in the aggressive behaviour of the native species towards conspecifics versus heterospecifics. Inherent species recognition and higher aggressive behaviour may limit species coexistence as they are expected to favour A. oculatus during territorial interactions with A. cristatellus. While more studies are needed to understand the causes of these behavioural shifts and their consequences on long-term species coexistence, the present study highlights the role of behaviour as a first response to interspecific interactions.
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http://dx.doi.org/10.1111/1365-2656.13223DOI Listing
July 2020

Lipid protection by polyphenol-rich apple matrices is modulated by pH and pepsin in in vitro gastric digestion.

Food Funct 2019 Jul;10(7):3942-3954

UMR408 SQPOV "Safety and Quality of Plant Products", INRA, University of Avignon, F-84000 Avignon, France.

Lipid oxidation takes place in the gastric tract after the ingestion of a Western diet rich in ω-6 polyunsaturated fatty acids (PUFA) and red meat (heme iron). The incorporation of oxidation products such as 4-hydroxy-2-nonenal (4-HNE) into low-density lipoproteins is further correlated to endothelial dysfunction. Gastric postprandial stress could thus be reduced by antioxidant phytomicronutrients. The aim of this study was to investigate dietary lipid oxidation and its inhibition by apple polyphenols under different matrix forms (fresh fruit, puree, extract) under in vitro gastric digestion conditions. A deep insight was given into the two factors pH and pepsin governing the metmyoglobin-initiated lipid oxidation of sunflower oil-in-water emulsions simulating the physical state of dietary lipids. Our results first showed that pepsin accelerated lipid oxidation at pH 5 through the formation of a micro-metmyoglobin form likely displaying a higher accessibility to lipids. Spectroscopic studies further highlighted the formation of a reversible unfolded metmyoglobin form at pH 3 which was shown to be more pro-oxidant in the absence of pepsin. At nutritional levels, the three apple matrices inhibited less efficiently the accumulation of lipid-derived conjugated dienes and 4-HNE at pH 5 when pepsin was present whereas at pH 3 the opposite was true. High initial bioaccessibilities of monomeric phenolic compounds were evidenced for both puree (57-74%) and the phenolic extract (79-96%) compared to fresh apple (1-14%) supporting their greater antioxidant capacity. By contrast, the bioaccessibility of dimer B2 was low for all matrices suggesting non-covalent binding to apple pectins.
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http://dx.doi.org/10.1039/c9fo00705aDOI Listing
July 2019

Procyanidin-Cell Wall Interactions within Apple Matrices Decrease the Metabolization of Procyanidins by the Human Gut Microbiota and the Anti-Inflammatory Effect of the Resulting Microbial Metabolome In Vitro.

Nutrients 2019 Mar 19;11(3). Epub 2019 Mar 19.

Université Clermont Auvergne, INRA, UMR 0454 MEDIS, F-63000 Clermont-Ferrand, France.

B-type oligomeric procyanidins in apples constitute an important source of polyphenols in the human diet. Their role in health is not known, although it is suggested that they generate beneficial bioactive compounds upon metabolization by the gut microbiota. During apple processing, procyanidins interact with cell-wall polysaccharides and form stable complexes. These interactions need to be taken into consideration in order to better assess the biological effects of fruit constituents. Our objectives were to evaluate the impact of these interactions on the microbial metabolization of cell walls and procyanidins, and to investigate the potential anti-inflammatory activity of the resulting metabolome, in addition to analyzing the taxonomical changes which the microbiota undergo. In vitro fermentation of three model apple matrices with microbiota from 4 healthy donors showed that the binding of procyanidins to cell-wall polysaccharides, whether covalently or non-covalently, substantially reduced procyanidin degradation. Although cell wall-unbound procyanidins negatively affected carbohydrate fermentation, they generated more hydroxyphenylvaleric acid than bound procyanidins, and increased the abundance of and genera. The best results in terms of production of anti-inflammatory bioactive metabolites were observed from the apple matrix with no bonds between procyanidins and cell wall polysaccharides, although the matrix with non-covalent bonds was not far behind.
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http://dx.doi.org/10.3390/nu11030664DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6471247PMC
March 2019

INFOGEST static in vitro simulation of gastrointestinal food digestion.

Nat Protoc 2019 04 18;14(4):991-1014. Epub 2019 Mar 18.

GMPA, AgroParisTech, INRA, Université Paris-Saclay, Thiverval-Grignon, France.

Developing a mechanistic understanding of the impact of food structure and composition on human health has increasingly involved simulating digestion in the upper gastrointestinal tract. These simulations have used a wide range of different conditions that often have very little physiological relevance, and this impedes the meaningful comparison of results. The standardized protocol presented here is based on an international consensus developed by the COST INFOGEST network. The method is designed to be used with standard laboratory equipment and requires limited experience to encourage a wide range of researchers to adopt it. It is a static digestion method that uses constant ratios of meal to digestive fluids and a constant pH for each step of digestion. This makes the method simple to use but not suitable for simulating digestion kinetics. Using this method, food samples are subjected to sequential oral, gastric and intestinal digestion while parameters such as electrolytes, enzymes, bile, dilution, pH and time of digestion are based on available physiological data. This amended and improved digestion method (INFOGEST 2.0) avoids challenges associated with the original method, such as the inclusion of the oral phase and the use of gastric lipase. The method can be used to assess the endpoints resulting from digestion of foods by analyzing the digestion products (e.g., peptides/amino acids, fatty acids, simple sugars) and evaluating the release of micronutrients from the food matrix. The whole protocol can be completed in ~7 d, including ~5 d required for the determination of enzyme activities.
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http://dx.doi.org/10.1038/s41596-018-0119-1DOI Listing
April 2019

The effect of recent competition between the native and the invasive on display behavior.

PeerJ 2018 15;6:e4888. Epub 2018 Jun 15.

Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA.

Invasive species are a global threat to biodiversity. Cases where the invasion has been tracked since its beginning are rare, however, such that the first interactions between invasive and native species remain poorly understood. Communication behavior is an integral part of species identity and is subject to selection. Consequently, resource use and direct interference competition between native and invasive species may drive its evolution. Here, we tested the role of interactions between the recently introduced invasive lizard and the native on variation in behavior and communication in Calibishie (Dominica). From May to June 2016, we filmed 122 adult males of both species displaying in banana farms under two contexts (allopatry and sympatry). We then recorded (i) the proportion of time spent displaying and (ii) the relative frequency of dewlap vs. push-up displays. To control for habitat variation, we measured and compared the habitat characteristics (canopy openness and habitat openness) of 228 males in allopatry and sympatry. While the habitat characteristics and total display-time did not differ between the contexts for the two species, the proportion of display-time spent dewlapping by decreased in sympatry. The display of did not differ between the contexts, however. Shifts in microhabitat use, predation pressure, or interspecific interference are potential factors which might explain the behavioral changes in display observed in . This study highlights the role of behavioral traits as a first response of an invasive species to recent competition with a closely related native species.
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http://dx.doi.org/10.7717/peerj.4888DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6005165PMC
June 2018

Phenolic compounds and antioxidant activity of lingonberry (Vaccinium vitis-idaea L.) leaf, stem and fruit at different harvest periods.

Food Chem 2018 Jun 9;252:356-365. Epub 2018 Jan 9.

INRA, University of Avignon, UMR408 Safety and Quality of Plant Products, F-84000 Avignon, France. Electronic address:

Fruits and aerial parts of lingonberry could be better developed as dietary supplements if the composition in bioactive phenolic compounds and the best period for collection were known. UPLC/MS analysis revealed the predominant presence of arbutin in leaf and that of flavanols in stems harvested in May, July and September. Anthocyanins, flavanols and benzoic acid derivatives were equally present in fruits. Stem and leaf are highly homologous with (+)-catechin, A- and B-type dimers/trimers, and two quercetin glycosides as major contributors. No or only weak seasonal variations were highlighted for all phenolic classes. Additionally, flavanol oligomers showed a lower mDP for fruit (3-4) than for stem and leaf (4-6). The rate of A-type linkage was 3-5% with A-type subunits in extension mainly. Finally, the content in phenolic compounds (UPLC) correlated well with TPC and the DPPH radical scavenging activity although leaf and stem constituents reacted differently in both antioxidant tests.
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http://dx.doi.org/10.1016/j.foodchem.2018.01.052DOI Listing
June 2018

The matrix of fruit & vegetables modulates the gastrointestinal bioaccessibility of polyphenols and their impact on dietary protein digestibility.

Food Chem 2018 Feb 25;240:314-322. Epub 2017 Jul 25.

Université Clermont Auvergne, INRA, UNH, Unité de Nutrition Humaine, F-63000 Clermont-Ferrand, France.

Fruit and vegetables (F&V) polyphenols have numerous positive health effects, ascribed either to their antioxidant activity within the gastrointestinal tract (GIT) or to bioactivity of their absorbed metabolites. The effect of the F&V matrix on the gastrointestinal bioaccessibility of polyphenols was investigated along with its possible interaction with protein digestion. Minipigs were fed a complete meal with either cubed F&V (apple, plum, artichoke) added, or the corresponding phenolic extract (PE). Gastric and ileal chymes were kinetically collected over the postprandial period. The overall polyphenol bioaccessibility in the stomach was found to be 1.5% and 3.1% after F&V and PE consumption, respectively. The lower release rate from artichoke than from apple showed evidence of a plant effect. Flavanol monomers and glucoside conjugates were not recovered in the ileum in agreement with their absorption in the upper GIT. Interestingly, PE, but not F&V, significantly decreased the speed and efficiency of dietary protein digestion.
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http://dx.doi.org/10.1016/j.foodchem.2017.07.104DOI Listing
February 2018

Warfarin and Flavonoids Do Not Share the Same Binding Region in Binding to the IIA Subdomain of Human Serum Albumin.

Molecules 2017 Jul 11;22(7). Epub 2017 Jul 11.

Department of Medicinal Chemistry, University of Zagreb, Faculty of Pharmacy and Biochemistry, Ante Kovačića 1, 10000 Zagreb, Croatia.

Human serum albumin (HSA) binds a variety of xenobiotics, including flavonoids and warfarin. The binding of another ligand to the IIA binding site on HSA can cause warfarin displacement and potentially the elevation of its free concentration in blood. Studies dealing with flavonoid-induced warfarin displacement from HSA provided controversial results: estimated risk of displacement ranged from none to serious. To resolve these controversies, in vitro study of simultaneous binding of warfarin and eight different flavonoid aglycons and glycosides to HSA was carried out by fluorescence spectroscopy as well as molecular docking. Results show that warfarin and flavonoids do not share the same binding region in binding to HSA. Interactions were only observed at high warfarin concentrations not attainable under recommended dosing regimes. Docking experiments show that flavonoid aglycons and glycosides do not bind at warfarin high affinity sites, but rather to different regions within the IIA HSA subdomain. Thus, the risk of clinically significant warfarin-flavonoid interaction in binding to HSA should be regarded as negligible.
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http://dx.doi.org/10.3390/molecules22071153DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6152318PMC
July 2017

Seasonal variations of the phenolic constituents in bilberry (Vaccinium myrtillus L.) leaves, stems and fruits, and their antioxidant activity.

Food Chem 2016 Dec 17;213:58-68. Epub 2016 Jun 17.

UMR408 Safety and Quality of Plant Products, INRA, University of Avignon, F-84000 Avignon, France. Electronic address:

The seasonal variations of the content and diversity of phenolic compounds, as well as the antioxidant activity of leaves, stems and fruits of bilberry collected in May, July and September, were evaluated for two consecutive years. UPLC/MS(n) analyses showed the predominance of anthocyanins in fruits, caffeic acid derivatives in leaves whereas flavanol oligomers represented more than half of the phenolic compounds in stems. Thioacidolysis revealed degrees of polymerization between 2 and 4 and (-)-epicatechin as the main flavanol unit. The sum of the phenolic compounds by UPLC was highly correlated with the total polyphenol content and the antioxidant activity in the DPPH test for all the extracts except for May leaves. The latter were relatively rich in p-coumaric acid derivatives. Seasonal effects were more marked for leaves, which exhibited higher antioxidant activities and phenolic contents in July and September when these parameters were at their highest in July for stems.
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http://dx.doi.org/10.1016/j.foodchem.2016.06.042DOI Listing
December 2016

Quantification of 4-hydroxy-2-nonenal-protein adducts in the in vivo gastric digesta of mini-pigs using a GC-MS/MS method with accuracy profile validation.

Food Funct 2016 Aug 15;7(8):3497-504. Epub 2016 Jul 15.

INRA, UR370 Animal Products Quality Unit, Clermont-Ferrand/Theix, F-63122 Saint-Genès-Champanelle, France.

Hydroxyalkenals are lipid oxidation end-products resulting from the oxidation of polyunsaturated fatty acids (PUFA). This study aimed at quantifying the production of 4-hydroxy-2-nonenal-protein adducts (HNE-P) via Michael addition from n-6 PUFA oxidation in the gastric digesta of mini-pigs after the consumption of meat-based meals with different plant antioxidant contents. Using the accuracy profile procedure, we validated an extraction protocol for the quantification of HNE-P by GC-MS/MS in gastric contents. The formation of HNE-P in the gastric compartment was observed for the first time, with concentrations ranging from less than 0.52 to 1.33 nmol HNE-P per 500 mg digesta. Nevertheless, most gastric HNE-P levels were below the limit of quantification of 0.52 nmol HNE-P per 500 mg digesta. In this animal study, the protective effect of plant antioxidant sources on HNE-P formation was not evidenced contrasting with the results using TBARS as markers.
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http://dx.doi.org/10.1039/c6fo00413jDOI Listing
August 2016

Space use variation in co-occurring sister species: response to environmental variation or competition?

PLoS One 2015 18;10(2):e0117750. Epub 2015 Feb 18.

Institut des Sciences de l'Evolution de Montpellier UMR5554 (UM2, CNRS, IRD, EPHE), Université Montpellier 2, CC065, 34095 Montpellier, France; School of Animal, Plant and Environmental Science, University of the Witwatersrand, P/Bag 3, 2050 Wits, South Africa.

Coexistence often involves niche differentiation either as the result of environmental divergence, or in response to competition. Disentangling the causes of such divergence requires that environmental variation across space is taken into account, which is rarely done in empirical studies. We address the role of environmental variation versus competition in coexistence between two rodent species: Rhabdomys bechuanae (bechuanae) and Rhabdomys dilectus dilectus (dilectus) comparing their habitat preference and home range (HR) size in areas with similar climates, where their distributions abut (allopatry) or overlap (sympatry). Using Outlying Mean Index analyses, we test whether habitat characteristics of the species deviate significantly from a random sample of available habitats. In allopatry, results suggest habitat selection: dilectus preferring grasslands with little bare soil while bechuanae occurring in open shrublands. In sympatry, shrubland type habitats dominate and differences are less marked, yet dilectus selects habitats with more cover than bechuanae. Interestingly, bechuanae shows larger HRs than dilectus, and both species display larger HRs in sympatry. Further, HR overlaps between species are lower than expected. We discuss our results in light of data on the phylogeography of the genus and propose that evolution in allopatry resulted in adaptation leading to different habitat preferences, even at their distribution margins, a divergence expected to facilitate coexistence. However, since sympatry occurs in sites where environmental characteristics do not allow complete species separation, competition may explain reduced inter-species overlap and character displacement in HR size. This study reveals that both environmental variation and competition may shape species coexistence.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0117750PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333358PMC
November 2015

Fruits, vegetables and their polyphenols protect dietary lipids from oxidation during gastric digestion.

Food Funct 2014 Sep;5(9):2166-74

INRA, UR370 Quality of Animal Products F-63122 St Genès-Champanelle, France.

Previous studies indicate that the ingestion of oxidized vegetable oils leads to the incorporation of chemically reactive molecules issued from the decomposition of the initial lipid hydroperoxides into lipoproteins. The aim of the present study is to investigate the oxidation of dietary lipids in the gastric compartment and their inhibition by plant polyphenols provided either as fruit and vegetables (F&V) or an extract. Six minipigs received a standard Western diet containing primarily sunflower oil, ground beef meat, and starch. Polyphenols in different matrix forms were ingested either as cubed F&V or as the corresponding hydroacetonic extract. Sampling of the gastric digesta allowed the kinetic investigation of pH, heme and non-heme iron forms, total lipids, lipid-derived conjugated dienes (CD) and TBARS. F&V and the corresponding polyphenol extract delayed the gastric digestion process as shown for total lipid and heme iron contents. This study also demonstrated the occurrence of in vivo oxidation of dietary lipids in the presence of meat iron. Interestingly, F&V played a protective role by totally inhibiting the accumulation of CD while largely decreasing the formation of TBARS. The polyphenol extract similarly slowed down the TBARS formation although it had no effect on the CD accumulation.
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http://dx.doi.org/10.1039/c4fo00269eDOI Listing
September 2014

Exposure or release of ferulic acid from wheat aleurone: impact on its antioxidant capacity.

Food Chem 2013 Dec 23;141(3):2355-62. Epub 2013 May 23.

SupAgro-INRA-UMII-CIRAD, UMR 1208 Agropolymer Engineering and Emerging Technologies, 2, Place Pierre Viala, F-34060 Montpellier, France.

The relationship between the aleurone cell integrity and the exposure or release of bioavailable ferulic acid (FA) with the antioxidant capacity of aleurone in in vitro and under simulated gastric conditions was explored. The antioxidant capacity of aleurone was increased by around 2-fold when its median particle size was reduced to under 50 μm. The opening of aleurone cells increased the physical exposure of FA bound to the insoluble polysaccharides, which seemed to be responsible of the increased antioxidant capacity. Synergistic combination of xylanase and feruloyl esterase was found to be the most efficient enzymatic treatment releasing up to 86% of total FA in bioaccessible forms. This enzymatic treatment significantly enhanced the radical scavenging activity of aleurone by up to 4-fold, which overlapped the overall antioxidant potential estimated from the total content of FA in aleurone. The improvement in the antioxidant capacity of aleurone was also observed in the simulated gastric digestion by inhibition of lipid oxidation.
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http://dx.doi.org/10.1016/j.foodchem.2013.04.132DOI Listing
December 2013

[Preventable drug events in acute geriatric unit].

Geriatr Psychol Neuropsychiatr Vieil 2013 Mar;11(1):15-20

Service de médecine interne, Hôpital Edouard Herriot, Hospices civils de Lyon, Lyon, France.

Unlabelled: The study was performed on 313 patients hospitalized in an acute geriatric unit during a six-month period and aimed at determine the prevalence of adverse drug events (ADE) and the preventability of them.

Methods: ADE were determined by the medical information unit. Preventability was determined by inadequacy with standards of care, medication-related factors (non respect of contra-indication) and explicit lists of harmful medication in the elderly.

Results: prevalence of ADE was 12.7%. The mean age of patients was 84.8 years old. The number of comorbidities per patient was 3 and medications consumed were 7.7±3.1. 70% of them were ambulatory patient with an activity of daily living of 3.8±1.76. Cardiovascular (39%), psychotropic (36.6%) and morphinic (7.3%) medicines were the most frequently involved. The symptoms that occurred most frequently were haemorragia (28.6%), falls (14.3%), and sleepiness (9.5%) and were preventable in 31% of cases.

Conclusion: elderly patients with multiple pathologies are at high risk for ADE. These ADE are preventable by using scores, following standards of care, respecting contra-indications of medications.
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http://dx.doi.org/10.1684/pnv.2013.0399DOI Listing
March 2013

The impact of industrial processing on health-beneficial tomato microconstituents.

Food Chem 2012 Oct 29;134(4):1786-95. Epub 2012 Mar 29.

INRA, UMR408, Safety and Quality of Plant Products, F-84914 Avignon, France.

The effect of industrial processing was investigated on the stability of tomato carotenoids, phenolic compounds and ascorbic acid. A deep insight in the processed products allowed the quantification of caffeic acid hexosides, which are far more important contributors than the well-known chlorogenic acid, dicaffeoylquinic acids and quercetin oligosaccharides (new feruloyl, sinapoyl and syringoyl derivatives of quercetin apiosylrhamnosylglucoside). (E)-β-Carotene and (E)-lycopene were also quantified along with different mono- and di-(Z)-isomers of lycopene which were tentatively assigned. Processing of fresh tomato into paste had an overall positive effect on the contents in phenolic compounds, no effect on lycopene and a slight and high detrimental effect on β-carotene and ascorbic acid, respectively. The balance between the increase in tomato matrix extractability and microconstituent catabolism was further observed in two contrasted transformations of paste into sauce. Overall, the nutritional quality of tomato-processed products, except for ascorbic acid, is mainly preserved through manufacture.
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http://dx.doi.org/10.1016/j.foodchem.2012.03.077DOI Listing
October 2012

Inhibition of iron-induced lipid peroxidation by newly identified bacterial carotenoids in model gastric conditions: comparison with common carotenoids.

Food Funct 2013 Apr;4(5):698-712

INRA, UMR408, Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France.

Newly identified spore-forming pigmented marine bacteria, Bacillus indicus HU36 and Bacillus firmus GB1, are sources of carotenoids (mainly 15 yellow and orange pigments and 13 pink pigments, respectively) with original structures. These bacterial carotenoids were evaluated for their ability to inhibit the iron-induced peroxidation of linoleic acid micelles, or sunflower oil-in-water emulsions, in comparison with β-carotene, lycopene and astaxanthin. Lipid peroxidation was carried out in acidic conditions and initiated by dietary heme or non-heme iron (metmyoglobin or Fe(II), respectively) so as to simply simulate the postprandial gastric medium, a possible site for dietary oxidative stress. Lipid hydroperoxide formation and carotenoid consumption were followed by UV-vis spectroscopy and appropriate indicators of the antioxidant activity were estimated in each model. The bacterial carotenoids were found to be better inhibitors of heme-induced lipid peroxidation than the reference carotenoids as a likely consequence of their location closer to the interface in micelles and lipid droplets. However, this trend was not confirmed in lipid peroxidation induced by non-heme iron, possibly because of the redox recycling of Fe(II) by carotenoids. The quantitative kinetic analysis of the peroxidation curves suggests that the carotenoids mainly inhibit the propagation phase of lipid peroxidation by direct scavenging of the lipid peroxyl radicals, in agreement with independent experiments showing that carotenoids are unable to reduce the one-electron oxidized form of metmyoglobin (ferrylmyoglobin), a model of initiating species in heme-induced lipid peroxidation. Overall, carotenoids from Bacillus indicus HU36 and Bacillus firmus GB1 were found to be interesting antioxidants to fight postprandial oxidative stress in the stomach.
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http://dx.doi.org/10.1039/c3fo30334aDOI Listing
April 2013

When parasitoid males make decisions: information used when foraging for females.

PLoS One 2012 3;7(10):e46706. Epub 2012 Oct 3.

Université de Rennes I, Unité Mixte de Recherche (UMR) Centre National de la Recherche Scientifique (CNRS) 6553 EcoBio, Rennes, France.

Optimal foraging models predict how an organism allocates its time and energy while foraging for aggregated resources. These models have been successfully applied to organisms such as predators looking for prey, female parasitoids looking for hosts, or herbivorous searching for food. In this study, information use and patch time allocation were investigated using male parasitoids looking for mates. The influence of the former presence of females in absence of mates and the occurrence of mating and other reproductive behaviours on the patch leaving tendency was investigated for the larval parasitoid Asobara tabida. Although males do not modify their patch residence time based on the number of females that visited the patch, they do show an increase in the patch residence time after mating a virgin female and performing courtship behaviour such as opening their wings. These results are in concordance with an incremental mechanism, as it has been described for females of the same species while foraging for hosts. The similarities between males and females of the same species, and the conditions under which such a patch-leaving decision rule is fitted are discussed. This is the first study describing an incremental effect of mating on patch residence time in males, thus suggesting that similar information use are probably driving different organisms foraging for resource, regardless of its nature.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0046706PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463545PMC
May 2013

Dietary iron-initiated lipid oxidation and its inhibition by polyphenols in gastric conditions.

J Agric Food Chem 2012 Sep 28;60(36):9074-81. Epub 2012 Aug 28.

UMR408 Safety and Quality of Plant Products, INRA, F-84000 Avignon, France.

The gastric tract may be the first site where food is exposed to postprandial oxidative stress and antioxidant activity by plant micronutrients. After food intake, dietary iron, dioxygen, and emulsified lipids come into close contact and lipid oxidation may take place. This study investigated lipid oxidation and its inhibition by dietary polyphenols in gastric-like conditions. Lipid oxidation induced by heme and nonheme iron was studied in acidic sunflower oil-in-water emulsions. The emulsifier type (bovine serum albumin, phospholipids), pH, and iron form were found to be factors governing the oxidation rates. Quercetin, rutin, and chlorogenic acid highly inhibited the metmyoglobin-initiated lipid oxidation in both emulsified systems at pH 5.8. Additionally, quercetin inhibited nonheme iron-initiated processes, while it was inefficient with hematin as an initiator. The presence of human gastric juice did not influence lipid oxidation, although it diminished the antioxidant activity of phenolics. Model emulsions may thus be valuable tools to study the gastric stability of polyunsaturated lipids.
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http://dx.doi.org/10.1021/jf302348sDOI Listing
September 2012

Binding of citrus flavanones and their glucuronides and chalcones to human serum albumin.

Food Funct 2011 Oct 28;2(10):617-26. Epub 2011 Sep 28.

INRA, UMR408, Safety and Quality of Plant Products, 84000, Avignon, France.

Naringenin and hesperetin glycosides are the major polyphenols (flavanones) of citrus fruits and juices and are thought to participate in the cardioprotective effects of diets rich in plant products. Naringenin and hesperetin glucuronides (resulting from conjugation at the A- or B-ring) are the main circulating metabolites in humans and their binding to human serum albumin (HSA) is expected to modulate their half-life in plasma and tissue distribution. In this work, the binding of flavanone glucuronides to HSA was investigated by fluorescence spectroscopy. Binding constants in the range of 3-9 × 10(4) M(-1) were estimated. The affinity of glucuronides for HSA is close to that of naringenin and hesperetin themselves. Competition experiments in the presence of the fluorescent probes dansylsarcosine and quercetin were used to gain information on the flavanone binding site. Naringenin and hesperetin chalcones were also included for comparison as their glucuronides too were detected in the general circulation. Naringenin and hesperetin chalcones spontaneously undergo cyclization back to the parent flavanones under neutral conditions. The cyclization was significantly slowed down by HSA but led to a racemic mixture of (2R) and (2S) flavanones in the absence or presence of HSA.
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http://dx.doi.org/10.1039/c1fo10077gDOI Listing
October 2011

Food grade lingonberry extract: polyphenolic composition and in vivo protective effect against oxidative stress.

J Agric Food Chem 2011 Apr 4;59(7):3330-9. Epub 2011 Mar 4.

CHR-Hansen-SAS, 92 avenue des Baronnes, 34730 Prades-le-Lez, France.

Fractionation of the polyphenols constituting a food grade lingonberry extract (Vaccinium vitis-idaea) highlighted a composition more complex than described until now in the berry. Procyanidins B1, B2, and A2 were identified by UPLC/ESI-MS(2) along with the presence of other flavanol oligomers. Processing induced the release of large amounts of aglycones for ferulic acid, p-coumaric acid, and quercetin. The described anthocyanic composition of lingonberry was completed with hexoside derivatives of peonidin, petunidin, malvidin, and delphinidin. Besides confirmation of in vitro antioxidant activity, in vivo study was performed on rats fed a diet inducing oxidative stress. Supplementation with lingonberry extract significantly decreased the total oxidant status and favorably affected antioxidant defense enzymes in red blood cells and liver. A drop in the serum reduced glutathione level was also prevented, and uric acid was maintained at low level, confirming the antioxidant activity of the extract (5% proanthocyanidins) from a dosage of 23 mg/kg of body weight.
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http://dx.doi.org/10.1021/jf103965bDOI Listing
April 2011

CYP1A1 induction in the colon by serum: involvement of the PPARα pathway and evidence for a new specific human PPREα site.

PLoS One 2011 Jan 31;6(1):e14629. Epub 2011 Jan 31.

INRA, UMR1260, Nutriments Lipidiques et Prévention des Maladies Métaboliques, Marseille, France.

Background: We previously showed that blood serum induced cytochrome P450 1A1 (CYP1A1) monooxygenase expression in vitro.

Objective: Our purpose was (i) to identify the molecular mechanism involved and (ii) to characterize the inducer compound(s) in serum involved at least in part.

Methods: Serum was fractionated on hydrophobic columns. PPARα involvement was demonstrated by gene reporter assays, DNA mutagenesis and EMSA. Gene expression was evaluated by qRT-PCR. Serum samples were analyzed using HS-SPME-GC-MS.

Results: The inductive effect of serum did not depend on the AhR pathway and was enhanced by cotransfection of PPARα cDNA. Mutations in the PPAR response elements of the CYP1A1 gene promoter suppressed this effect. One of the PPRE sites appeared highly specific for human PPARα, an unreported PPRE property. A link was found between CYP1A1 inducibility and serum hydrophobic compounds. Characterization of sera showed that hexanal, a metabolite produced by peroxidation of linoleic acid, was involved in CYP1A1 induction by serum, possibly along with other serum entities.

Conclusion: We demonstrate that serum induces CYP1A1 via the PPARα pathway and that hexanal is one of the serum inducers. The two PPRE sites within the CYP1A1 promoter are functional and one of them is specific for PPARα.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0014629PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3031628PMC
January 2011

Vitamin D intestinal absorption is not a simple passive diffusion: evidences for involvement of cholesterol transporters.

Mol Nutr Food Res 2011 May 31;55(5):691-702. Epub 2011 Jan 31.

INRA, UMR1260 Nutriments Lipidiques et Prévention des Maladies Métaboliques, Marseille, France.

Scope: It is assumed that vitamin D is absorbed by passive diffusion. However, since cholecalciferol (vitamin D(3) ) and cholesterol display similar structures, we hypothesized that common absorption pathways may exist.

Methods And Results: Cholecalciferol apical transport was first examined in human Caco-2 and transfected Human embryonic kidney (HEK) cells. Cholecalciferol uptake was then valuated ex vivo and in vivo, using either wild-type mice, mice overexpressing Scavenger Receptor class B type I (SR-BI) at the intestinal level or mice treated or not with ezetimibe. Cholecalciferol uptake was concentration-, temperature- and direction-dependent, and was significantly impaired by a co-incubation with cholesterol or tocopherol in Caco-2 cells. Moreover Block Lipid Transport-1 (SR-BI inhibitor) and ezetimibe glucuronide (Niemann-Pick C1 Like 1 inhibitor) significantly decreased cholecalciferol transport. Transfection of HEK cells with SR-BI, Cluster Determinant 36 and Niemann-Pick C1 Like 1 significantly enhanced vitamin D uptake, which was significantly decreased by the addition of Block Lipid Transport-1, sulfo-N-succinimidyl oleate (Cluster Determinant 36 inhibitor) or ezetimibe glucuronide, respectively. Similar results were obtained in mouse intestinal explants. In vivo, cholecalciferol uptake in proximal intestinal fragments was 60% higher in mice overexpressing SR-BI than in wild-type mice (p<0.05), while ezetimibe effect remained non-significant.

Conclusion: These data show for the first time that vitamin D intestinal absorption is not passive only but involves, at least partly, some cholesterol transporters.
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http://dx.doi.org/10.1002/mnfr.201000553DOI Listing
May 2011

Influence of serum albumin and the flavonol quercetin on the peroxidase activity of metmyoglobin.

Free Radic Biol Med 2010 May 1;48(9):1162-72. Epub 2010 Feb 1.

INRA, University of Avignon, UMR408, F-84000 Avignon, France.

Metmyoglobin (MbFe(III)), a major form of dietary iron, is an efficient inducer of lipid and protein oxidation. Indeed, MbFe(III) is able to cleave hydrogen peroxide and lipid hydroperoxides with subsequent formation of ferrylmyoglobin (MbFe(IV)=O) and lipid oxyl and peroxyl radicals. In the first part of this work, the mechanism of the reaction between MbFe(III) and H(2)O(2) is revisited with an emphasis on the influence of bovine serum albumin (BSA). BSA does not affect the rate of MbFe(IV)=O formation but inhibits the formation of a redox-inactive green pigment (heme-protein cross-link species). Although tightly bound to BSA, the flavonol quercetin is still able to reduce MbFe(IV)=O as a likely result of long-range electron transfers within a protein-protein complex. In the second part, BSA is shown to strongly slow down the metmyoglobin-catalyzed consumption of linoleic acid hydroperoxides with formation of ketones as the main products. In the process, only low concentrations of ferrylmyoglobin are slowly accumulated. A catalytic mechanism is proposed that involves a one-electron-oxidized metmyoglobin species distinct from ferrylmyoglobin.
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http://dx.doi.org/10.1016/j.freeradbiomed.2010.01.037DOI Listing
May 2010

Chemical modeling of heme-induced lipid oxidation in gastric conditions and inhibition by dietary polyphenols.

J Agric Food Chem 2010 Jan;58(1):676-83

UMR408 Safety and Quality of Plant Products, INRA, University of Avignon, Avignon, France.

The gastric tract may be the first site exposed to diet-related oxidative stress. After food intake, dietary iron such as (met)myoglobin, the pigment of meat, oxygen, and polyunsaturated lipids come into close contact. The main goal of this work is the in vitro investigation of lipid oxidation taking place in the gastric compartment and its inhibition by dietary polyphenols. Oil-in-water emulsions stabilized either by bovine serum albumin (BSA) or egg yolk phospholipids (PL) were designed to model the gastric content. The metmyoglobin-initiated lipid oxidation led to the accumulation of lipid-derived conjugated dienes and volatile aldehydes. These reactions were faster in the BSA model than in the PL model, highlighting the influence of the interfacial composition. Quercetin, rutin, (+)-catechin, caffeic acid, and chlorogenic acid proved to be better inhibitors than alpha-tocopherol and ascorbic acid. Emulsions as models of the gastric environment are valuable tools to study the stability of macro- and micronutrients.
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http://dx.doi.org/10.1021/jf903054eDOI Listing
January 2010

Olive phenols efficiently inhibit the oxidation of serum albumin-bound linoleic acid and butyrylcholine esterase.

Biochim Biophys Acta 2009 Apr;1790(4):240-8

UMR408 Safety and Quality of Plant Products, INRA, University of Avignon, Domaine St Paul, Avignon, France.

Background: Olive phenols are widely consumed in the Mediterranean diet and can be detected in human plasma. Here, the capacity of olive phenols and plasma metabolites to inhibit lipid and protein oxidations is investigated in two plasma models.

Methods: The accumulation of lipid oxidation products issued from the oxidation of linoleic acid bound to human serum albumin (HSA) by AAPH-derived peroxyl radicals is evaluated in the presence and absence of phenolic antioxidants. Phenol binding to HSA is addressed by quenching of the Trp214 fluorescence and displacement of probes (quercetin, dansylsarcosine and dansylamide). Next, the esterase activity of HSA-bound butyrylcholine esterase (BChE) is used as a marker of protein oxidative degradation.

Results: Hydroxytyrosol, oleuropein, caffeic and chlorogenic acids inhibit lipid peroxidation as well as HSA-bound BChE as efficiently as the potent flavonol quercetin. Hydroxycinnamic derivatives bind noncompetitively HSA subdomain IIA whereas no clear site could be identified for hydroxytyrosol derivatives.

General Significance: In both models, olive phenols and their metabolites are much more efficient inhibitors of lipid and protein oxidations compared to vitamins C and E. Low postprandial concentrations of olive phenols may help to preserve the integrity of functional proteins and delay the appearance of toxic lipid oxidation products.
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http://dx.doi.org/10.1016/j.bbagen.2009.01.007DOI Listing
April 2009

Synthesis of hydroxycinnamic acid glucuronides and investigation of their affinity for human serum albumin.

Org Biomol Chem 2008 Nov 8;6(22):4253-60. Epub 2008 Oct 8.

UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université d'Avignon, F-84000, Avignon, France.

Hydroxycinnamic acids (HCAs) are among the most abundant dietary polyphenols. Recent bioavailability studies have shown that HCAs enter the blood circulation mainly as glucuronides, which are thus most likely to express their potential health effects. In this work, an efficient synthesis of HCA O-arylglucuronides is developed. As for many xenobiotics, the resilience of HCA O-arylglucuronides in plasma and subsequent delivery to tissues could be governed by their binding to human serum albumin (HSA). Hence, the affinity of HCA O-arylglucuronides for HSA and its possible binding site were investigated by fluorescence spectroscopy. HCA O-arylglucuronides turn out to be moderate HSA ligands (K in the range 1-4 x 10(4) M(-1)) that bind HSA in sub-domain IIA, competitively or noncompetitively with other sub-domain IIA ligands such as dansylamide and the flavonol quercetin.
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http://dx.doi.org/10.1039/b809965kDOI Listing
November 2008