References of "Schneider, Yves-Jacques"
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See detailCharacterization of Black locust (Robinia pseudoacacia L.) heartwood extractives: identification of resveratrol and piceatannol
Sergent, Thérèse; Kohnen, Stéphane; Jourez, Benoît ULg et al

in Wood Science and technology (2014)

Robinia pseudoacacia L. heartwood is characterized by a very high natural durability. However, a significant difference was observed between the mature and juvenile heartwood, the latter presenting less ... [more ▼]

Robinia pseudoacacia L. heartwood is characterized by a very high natural durability. However, a significant difference was observed between the mature and juvenile heartwood, the latter presenting less durability against fungi decay, which could be attributed to lower extractive content. In order to elucidate this idea, extractives from mature and juvenile heartwoods of black locust trees were investigated. Results showed that extractive and phenolic contents were higher in mature than in juvenile heartwoods. The identification of phenolic compounds by UPLC–DAD–MS/MS revealed, for the first time, the presence of resveratrol and piceatannol. These two stilbenes as well as the flavonoid dihydrorobinetin were present at the highest level in mature heartwood, and as they are known antifungals, they could account for the great durability of mature heartwood. The stilbenes were detected in significant amounts particularly in mature heartwood where piceatannol reached a level tenfold higher than that reported for Japanese knotweed roots, the primary natural source of these stilbenes, whereas resveratrol level was comparable with reported values. As resveratrol and piceatannol receive increasing demand for nutraceutical, cosmetic and, possibly, pharmaceutical purposes, due to their beneficial health effects, this study underlines the use of R. pseudoacacia as a promising sustainable and economical source of resveratrol and piceatannol. [less ▲]

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See detailRapport scientifique et technique final du projet HYDRASANTE
Boudry, Christelle ULg; François, Emmanuelle ULg; Nollevaux, Géraldine et al

Report (2013)

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See detailDrug delivery to inflamed colon by nanoparticles: comparison of different strategies
Coco, Régis; Plapied, Laurence; Pourcelle, Vincent et al

in International Journal of Pharmaceutics (2013), 440(1), 3-12

For inflammatory bowel disease (IBD) treatment, local delivery of molecules loaded in nanoparticles to the inflamed colon could be a promising strategy. The aim of this study was to investigate how drug ... [more ▼]

For inflammatory bowel disease (IBD) treatment, local delivery of molecules loaded in nanoparticles to the inflamed colon could be a promising strategy. The aim of this study was to investigate how drug-loaded polymeric nanoparticles target the site of inflammation and to analyse the influence of different colon-specific delivery strategies. Three different polymeric nanoparticles were formulated using ovalbumin (OVA) as a model drug. pH-sensitive nanoparticles were made with Eudragit® S100. Mucoadhesive nanoparticles were created with trimethylchitosan (TMC). A mix of polymers, PLGA, PEG-PLGA and PEG-PCL, were used to obtain a sustained drug delivery. Furthermore, ligands targeting immune cells (i.e. mannose) or the inflamed colon (i.e. a specific peptide) were grafted on the PEG chain of PCL. Interaction of nanoparticles with the intestinal epithelium was explored using Caco-2 monolayers designed to mimic an inflamed epithelium and then visualized using confocal laser microscopy. TMC nanoparticles had the highest apparent permeability for OVA in the untreated model. However, in the inflamed model, there were no difference between TMC, PLGA-based and Eudragit® nanoparticles. The uptake of nanoparticles in the inflamed mouse colon was assessed in a horizontal diffusion chamber. Mannose-grafted PLGA nanoparticles showed the highest accumulation of OVA in inflamed colon. Based on these results, active targeting of macrophages and dendritic cells may be a promising approach for targeting the colon in IBD. [less ▲]

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See detailRapport scientifique et technique du projet HYDRASANTE (annee 3)
Boudry, Christelle ULg; François, Emmanuelle ULg; Nollevaux, Géraldine et al

Report (2013)

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See detailFood interactions : effects on health, consumer perception and impact on agro-food industries “FOODINTER”.
Scippo, Marie-Louise ULg; Blust, Ronny; Boniver, Delphine et al

Report (2011)

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See detailPotential of an in vitro toolbox combined with exposure data as a first step for the risk assessment of dietary chemical contaminants
Ribonnet, Laurence; Van Der Heiden, Edwige ULg; Nobels, Ingrid et al

in Food Additives & Contaminants (2011), 28(9), 1136-1158

In vitro risk assessment of dietary contaminants has become a priority in human food safety. This paper proposes an in vitro approach associating different complementary tools in an original toolbox and ... [more ▼]

In vitro risk assessment of dietary contaminants has become a priority in human food safety. This paper proposes an in vitro approach associating different complementary tools in an original toolbox and aims to improve the assessment of the toxicological impact of dietary contaminants at realistic human exposure levels, with a special focus on the intestinal compartment. The system is based on the use of four complementary cellular tools, namely stress gene induction in transgenic strains of Escherichia coli, modulation of the activity of key biotransformation enzymes (cytochrome P-450 (CYP) 1A1 and 3A4) in a human intestinal cell line, and activation of aryl hydrocarbon receptor (AhR) and oestrogenic receptor (ER)-dependent genes in agonistic and antagonistic assays with luciferase reporter cells. It was applied to four chosen model molecules: ochratoxin A (OTA) and deoxynivalenol (DON), two common food-borne mycotoxins, and imazalil (IMA) and benomyl (BEN), two fungicides widely occurring in foodstuffs. All these assays were performed at or around a realistic intestinal concentration, determined through a deterministic approach based on the calculation of a theoretical maximum daily intake (TMDI). Using the four model molecules, it is clearly highlighted that induction of CYP1A1 activity and inhibition of CYP3A4 activity occurred in Caco-2 cells at a realistic intestinal concentration of IMA. Furthermore, some bacterial stress genes were induced in a range of realistic concentrations, following exposure to DON and IMA. In addition, BEN clearly provoked an ER agonistic activity in a human oestrogen sensitive reporter cell line. All these results are in accordance with the literature, suggesting that the in vitro toolbox constitutes an interesting approach in order to obtain a first 'fingerprint' of dietary contaminants at realistic human exposure for further risk assessment. [less ▲]

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See detailModulation of CYP1A1 activity by a Ginkgo biloba extract in the human intestinal Caco-2 cells
Ribonnet, Laurence; Callebaut, Alfons; Nobels, Ingrid et al

in Toxicology Letters (2011), 202(3), 193-202

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See detailTargeting nanoparticles to M cells with non-peptidic ligands for oral vaccination
Freichels, Hélène ULg; Fievez, Virginie; Plapied, Laurence et al

Poster (2010, March 18)

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See detailCYP1A1 and CYP3A4 modulation by dietary flavonoids in human intestinal Caco-2 cells.
Sergent, Thérèse; Dupont, Isabelle; Van Der Heiden, Edwige ULg et al

in Toxicology Letters (2009), 191

Flavonoids have been proposed to exert beneficial effects in a multitude of disease states. However, evidence of potential toxic actions has also emerged. Since large doses of flavonoids can be ... [more ▼]

Flavonoids have been proposed to exert beneficial effects in a multitude of disease states. However, evidence of potential toxic actions has also emerged. Since large doses of flavonoids can be encountered in the intestine simultaneously with ingested drugs and pollutants, this study aimed at investigating nine individual flavonoid compounds and their interactions with the major intestinal isoforms of cytochrome P450, i.e. CYPs 1A1 and 3A4, using human intestinal Caco-2 cells cultivated in a serum-free medium. Genistein, quercetin and chrysin provoked a dose-dependent inducing effect on the CYP1A1 activity, measured with the EROD assay. However, they did not affect the CYP1A1 mRNA expression, suggesting they are not aryl hydrocarbon receptor-ligands in intestinal cells and act at a post-transcriptional level. Chrysin, at 50muM, was detected as a potent inhibitor of the TCDD-induced CYP1A1 activity, leading the activity to ca. 10% of the TCDD-control value (n=3), this effect involving, at least partly, direct interactions at the enzyme level. Quercetin was also shown to significantly inhibit the constitutive CYP3A4 activity, measured by the 6beta-(OH)-testosterone assay, and to impair its induction by 1,25-vitamin D(3). Chrysin, quercetin and genistein, were detected as significant inhibitors of the 1,25-vitamin D(3)-induced CYP3A4 activity. In vivo, these effects could result in reduced activation of procarcinogens and/or in drug bioavailability limitation. They underline the importance of intestinal studies to assess food safety and health risks linked to the ingestion of flavonoid-enriched supplements or functional foods. [less ▲]

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See detailCYP1A1 induction and CYP3A4 inhibition by the fungicide imazalil in the human intestinal Caco-2 cells-Comparison with other conazole pesticides
Sergent, Thérèse; Dupont, Isabelle; Jassogne, Coralie et al

in Toxicology Letters (2009), 184(3), 159-168

Imazalil (IMA) is a widely used imidazole-antifungal pesticide and. therefore. a food contaminant. This compound is also used as a drug (enilconazole). As intestine is the first site of exposure to ... [more ▼]

Imazalil (IMA) is a widely used imidazole-antifungal pesticide and. therefore. a food contaminant. This compound is also used as a drug (enilconazole). As intestine is the first site of exposure to ingested drugs and pollutants, we have investigated the effects of IMA, at realistic intestinal concentrations, on xenobiotic-metabolizing enzymes and efflux pumps by using Caco-2 cells, as a validated in vitro model of the human intestinal absorptive epithelium. For comparison, other conazole fungicides, i.e. ketoconazole, propiconazole and tebuconazole. were also studied. IMA induced cytochrome P450 (CYP) 1A1 activity to the same extent as benzo(a)pyrene (B(a)P) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in a dose-and time-dependent manner. Cell-free aryl hydrocarbon receptor (AhR) binding assay and reporter gene assay suggested that IMA is not an AhR-ligand, implying that IMA-mediated induction should involve an AhR-independent pathway. Moreover, IMA strongly inhibited the CYP3A4 activity in 1,25-vitamin D-3-induced Caco-2 cells. The other fungicides had weak or nil effects on CYP activities. Study of the apical efflux pump activities revealed that ketoconazole inhibited both P-glycoprotein (Pgp) and multidrug resistance-associated protein 2 (MRP-2) or breast cancer resistance protein (BCRP), whereas IMA and other fungicides did not. Our results imply that coingestion of IMA-contaminated food and CYP3A4- or CYP1A1-metabolizable drugs or chemicals could lead to drug bioavailability modulation or toxicological interactions, with possible adverse effects for human health. (C) 2008 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailLC-MS/MS multi-analyte method for mycotoxin determination in food supplements
Di Mavungu, Jose Diana; Monbaliu, Sofie; Scippo, Marie-Louise ULg et al

in Food Additives & Contaminants (2009), 26(6), 885-895

A multi-analyte method for the liquid chromatography-tandem mass spectrometric determination of mycotoxins in food supplements is presented. The analytes included A and B trichothecenes (nivalenol ... [more ▼]

A multi-analyte method for the liquid chromatography-tandem mass spectrometric determination of mycotoxins in food supplements is presented. The analytes included A and B trichothecenes (nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxyvalenol, neosolaniol, fusarenon-X, diacetoxyscirpenol, HT-2 toxin and T-2 toxin), aflatoxins (aflatoxin-B-1, aflaxoin-G(1) and aflatoxin-G(2)). Alternaria toxins (alternariol, alternariol methyl ether and altenuene), fumonisins (fumonisin-B-1, fumonisin-B-2 and fumonisin-B-3), ochratoxin A, zearalenone, beauvericin and sterigmatocystin. Optimization of the stimulataneous extraction of these toxins and the sample pretreatment procedure, as well as method validation were performed on maca (Lepidium meyenii) food supplements. The results indicated that the solvent mixture ethyl acetate/formic acid (95:5, v/v) n-hexane was applied as partial clean-up step to remove excess of co-extracted non-polar components. Further clean-up was performed on Oasis HLB(TM) cartidges. Samples were analysed using an Acquity UPLC system coupled to a Micromass Quattro Micro triple quadrupole mass spectrometer equipped with an electrospray interface operated in the positive-ion mode. Limits of detection and quantification were in the range of 0.3-30 ng g(-1) and 1-100 ng g(-1), respectively. Recovery yields were above 60% for most of the analytes, except for different food supplements such as soy (Glycine max) isoflavones, St John's wort (Hypericum perforatum), garlic (Allium sativum), Ginkgo biloba, and black radish (Raphanus niger) demonstrated the general applicability of the method. Due to different matrix effects observed in different food supplement samples, the standard addition approach was applied to perform correct quantitative analysis. In 56 out of 62 samples analysed, none of the 23 mycotoxins investigated was detected. Positive samples contained at least one of the toxins fumonisin-B-1, fumonisin-B-2, fumonisin-B-3 and ochratoxin A. [less ▲]

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See detailAdhesion and growth inhibitory effect of chicken egg yolk antibody (IgY) on Salmonella enterica serovars Enteritidis and Typhimurium in vitro.
Chalghoumi, Raja; Thewis, André ULg; Beckers, Yves ULg et al

in Foodborne Pathogens and Disease (2009), 6(5), 593-604

The protective effects of powder preparation of egg yolk immunoglobulin Y (IgY), specific to Salmonella Enteritidis and Salmonella Typhimurium outer membrane proteins (OMP), against these two Salmonella ... [more ▼]

The protective effects of powder preparation of egg yolk immunoglobulin Y (IgY), specific to Salmonella Enteritidis and Salmonella Typhimurium outer membrane proteins (OMP), against these two Salmonella sp. serovars were investigated in vitro in two different assays: adhesion-prevention and growth-inhibition. The adhesion-prevention assay was conducted using polarized monolayers of the human intestinal epithelial Caco-2 cell line. First, the conditions of Salmonella adherence to Caco-2 cells were optimized, and interferences of bacteria with the transepithelial electrical resistance (TER) of fully differentiated Caco-2 cell monolayers and the lactate dehydrogenase release upon exposure of the cells to Salmonella were evaluated. Both Salmonella sp. serovars were able to adhere to Caco-2 cells and decreased TER. Results from the adhesion-prevention assay demonstrated that specific IgY reduced the decrease in TER of the infected Caco-2 cell monolayers and blocked the Salmonella sp. adhesion in a concentration-dependent manner (p < 0.05). Nonspecific IgY also exhibited an inhibitory effect on these two parameters, but to a lesser extent than that of the specific IgY (p < 0.05). The protective effect of nonspecific IgY could be attributed to the low-density lipoprotein component of the water-soluble fraction of egg yolks that may not have been eliminated during ultrafiltration. The growth-inhibition assay revealed that specific IgY had an inhibitory effect on the bacterial growth, markedly during the late exponential phase, whereas nonspecific IgY failed to do so. Taken together, these results suggest that the in vitro growth inhibitory effect of specific IgY on Salmonella spp. resulted from the specific binding activity of these IgY to Salmonella sp. OMP. Passive immunization with Salmonella sp. OMP-specific IgY could thus be useful to prevent Salmonella colonization in broiler chickens and the subsequent carcass contamination during processing. [less ▲]

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See detailAnalysis of EU priority polycyclic aromatic hydrocarbons in food supplements using high performance liquid chromatography coupled to an ultraviolet, diode array or fluorescence detector
Danyi, Sophie ULg; Brose, François ULg; Brasseur, Catherine ULg et al

in Analytica Chimica Acta (2009), 633

High performance liquid chromatography coupled to an ultraviolet, diode array or fluorescence detector (HPLC/UV-FLD) has been used to set up a method to detect the 15(+1) EU priority polycyclic aromatic ... [more ▼]

High performance liquid chromatography coupled to an ultraviolet, diode array or fluorescence detector (HPLC/UV-FLD) has been used to set up a method to detect the 15(+1) EU priority polycyclic aromatic hydrocarbons (PAHs) in food supplements covering the categories of dried plants and plant extracts excluding oily products. A mini validation was performed and the following parameters have been determined: limit of detection, limit of quantification, precision, recovery and linearity. They were in close agreement with quality criteria described in the Commission Regulation (EC) No 333/2007 concerning the PAH benzo[a]pyrene in foodstuffs, except the not fluorescent cyclopenta[c,d]pyrene for which the UV detection leads to a higher limit of detection. Analysis of twenty commercial food supplements covering mainly the class of dried plants was performed to evaluate their PAHs contamination levels and to test the applicability of the method to various plant matrices. Fifty percent of analyzed samples showed concentration exceeding 2 gkg−1 for one or more PAHs. [less ▲]

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See detailFood flavonoid aryl hydrocarbon receptor-mediated agonistic/antagonistic/synergic activities in human and rat reporter gene assays
Van Der Heiden, Edwige ULg; Bechoux, Nathalie ULg; Muller, Marc ULg et al

in Analytica Chimica Acta (2009), 637

Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor mediating the adverse effects of dioxins and polycyclic aromatic hydrocarbons (PAHs). In this study, we investigated the genetic ... [more ▼]

Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor mediating the adverse effects of dioxins and polycyclic aromatic hydrocarbons (PAHs). In this study, we investigated the genetic-, time-, dose-, species- and tissue-dependent AhR-mediated agonistic/ antagonistic activities of three food flavonoids: quercetin, chrysin and genistein. To that end, four stably transfected cell lines were used in cell-based luciferase reporter gene assays: three lines were transformed with the ptKLuc vector harbouring four dioxinresponsive elements (DREs) upstream of the thymidine kinase promoter and the luciferase gene (HepG2-Luc, T-47D-Luc and H4IIE-ULg). The fourth is a patented cell line transformed with a different construct: H4IIE DR-CALUX®. Both H4IIE cells were compared for their genetic construction. Human hepatoma (HepG2-Luc) and human breast tumour (T-47D-Luc) cells were compared for tissue-dependent effects. Rat hepatoma (H4IIE-ULg) and human hepatoma (HepG2-Luc) cellswere compared for species-dependent activities.We concluded that quercetin, chrysin and genistein act in a time-, dose-, species- and tissue-specific way. For example, genistein displayed agonistic activities when exposed to rat hepatoma cells during 6h but not after 24 h. Flavonoids displayed agonistic/antagonistic activities in human breast tumour cells, depending on the exposure time, while in human hepatoma cells, only antagonistic activities of flavonoids were measured. In addition, we report, in all the cells, a synergy between an isoflavone and two food contaminants; the 2,3,7,8-tetrachlorodibenzop- dioxin and 3-methylcholanthrene, a PAH. In rat cells, this synergy occurred when cells were exposed to flavonoids and contaminant for 6h, while it was observed in human cells only after 24 h. [less ▲]

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See detailModulation of cytochrome P450 1A1 expression and activity in intestinal Caco-2 cells by components of Ginkgo biloba-based dietary supplements
Ribonnet, Laurence; Callebaut, Alfons; Scippo, Marie-Louise ULg et al

in Toxicology Letters (2009), 189

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See detailFunctional amphiphilic and degradable copolymers for drug delivery systems
Freichels, Hélène ULg; Pourcelle, Vincent; Plapied, Laurence et al

Poster (2008, December 18)

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