<p>Vitamin E is a natural lipophilic antioxidant contains eight structurally related forms, i.e., α-, β-, γ-, δ-tocopherols (αT, βT, γT, and δT) and corresponding tocotrienols. Recent research indicates that vitamin E forms are differentially metabolized to various carboxychromanols. Some these vitamin E metabolites have been shown to exhibit strong anti-inflammatory and anticancer effects, yet little is known about their bioavailability. Without this knowledge, it is impossible to assess the role of vitamin E metabolism in biological functions of vitamin E forms and their protective effects on chronic diseases. While αT and γT appear to improved gut health, the underlying mechanisms are not well understood. Furthermore, specific forms of vitamin E such as γT have been reported to have cancer-preventing effects, but their anticancer efficacy is relatively modest. For these reasons, this dissertation focused on the characterization of the pharmacokinetic formation of vitamin E metabolites after supplementation, and the investigation of the underlying mechanisms of the protective effect of vitamin E forms, αT and γT, on gut health, as well as anticancer efficacy of the combination of aspirin and γT on carcinogen-induced colon tumorigenesis.</p><p><br></p><p>The first project focuses on characterizing the pharmacokinetic formation of vitamin E metabolites after single dose supplementation of γ-tocopherol-rich mixed tocopherol (γTmT) and δ-tocotrienol (δTE). With our recently developed LC/MS/MS assay for quantifying vitamin E metabolites, we can simultaneously quantify the level of short-chain, long-chain, and sulfated carboxychromanols in plasma, urine, and fecal samples of supplemented animals. In this study, we investigated the pharmacokinetics including excretion of vitamin E forms and the formation of their metabolites after a single dose intragastric administration of tocopherols and tocotrienols in rats. We also measured vitamin E metabolites in the serum obtained from healthy humans after gT supplementation. In the plasma of rat, the pharmacokinetic profiles of γT and δTE are described as the following: γT, Cmax = 25.6 ± 9.1 μM, Tmax = 4 h; δTE, Cmax = 16.0 ± 2.3 μM, Tmax = 2 h. Sulfated CEHCs and sulfated 11’-COOHs were the predominant metabolites in the plasma of rat with Cmax of 0.4-0.5 μM (Tmax ~ 5-7 h) or ~0.3 μM (Tmax at 4.7 h), respectively. In 24-h urine, 2.7% of γT and 0.7% of dTE were excreted as conjugated CEHCs, the major identified urinary metabolites. In the feces, 17-45% of supplemented vitamers were excreted as un-metabolized forms and 4.9-9.2% as metabolites. The majority of metabolites excreted in feces were unconjugated carboxychromanols, among which 13’-COOHs constituted ~50% of total metabolites. Interestingly, 13’-COOHs derived from δTE were 2-fold higher than 13’-COOH from γT. Unlike rats, γ-CEHC is the predominant metabolites found in human plasma, although 11’-COOHs and 13’-COOHs (sulfated and unconjugated) were elevated by >20 folds responding to γT supplement. In this study, we found that tocopherols and tocotrienols, when taken as supplements, are mainly excreted as un-metabolized forms and long-chain carboxychromanols in feces. High fecal availability of 13’-COOHs may contribute to modulating effects on gut health.</p><p><br></p><p>The second project of my dissertation investigated the effect of vitamin E forms, αT and γT, on intestinal barrier function in a cellular model and a mouse colitis model. Inflammatory bowel diseases (IBD) are chronic idiopathic inflammatory conditions characterized by disruption of intestinal barrier integrity. Previous studies by others and us had demonstrated that vitamin E forms, αT and γT, can protect against chemical-induced colitis in animal models. However, the role of these vitamin E forms on intestinal barrier function has not been studied. Herein, we investigated the potential protective effects of vitamin E forms, αT and γT, on intestinal barrier function in a Caco-2 colon epithelial cell model and a dextran sodium sulfate (DSS)-induced colitis mouse model. In Caco-2 cells, pretreatment with 25mM αT and γT attenuated Caco-2 monolayer barrier dysfunction induced by 10 ng/mL TNF-α/IFN-γ, suggesting that these vitamin E forms protect intestinal barrier integrity in this cellular model. In male BALB/c mice, the supplementation of αT (0.05%) or γTmT (0.05%) when given 3 weeks before DSS treatment or at the same time as DSS treatment alleviated DSS-induced fecal bleeding and diarrhea symptoms in mice, and attenuated colon inflammation and colitis-associated damages. Additionally, αT and γTmT supplementation attenuated DSS-induced intestinal barrier dysfunction, as indicated by improving the level of occludin, a tight junction protein, in the colon and reducing lipopolysaccharide-binding protein (LBP) in the plasma. Furthermore, gut microbiota analysis demonstrated that αT and γTmT supplementation could modulate intestinal microbiome composition in mice with DSS treatment. DSS treatment reduced the relative abundance of Lachnospiraceae compared to healthy mice, and supplementation of αT and γT partially reversed this effect. Interestingly, the family Lachnospiraceae has been reported to decrease in IBD patients. Our study demonstrated the protective effects of vitamin E forms on intestinal barrier integrity in a cell-based model and a colitis model in mice. Furthermore, we demonstrated that these vitamin E forms caused favorable changes in the intestinal microbial population under colitis condition.</p><p><br></p><p>The third project of my dissertation evaluated the anticancer efficacy of the combination of aspirin and γT using an azoxymethane (AOM)-induced and colitis-promoted colon tumorigenesis mouse model. Extensive inflammation in the colon promotes the development of colorectal cancer (CRC). Eicosanoid production by pro-inflammatory enzymes, cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX) play a critical role in the initiation, progression, and invasion of CRC. Thus, nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, have been recommended for chemoprevention of CRC. However, long-term use of aspirin can cause many side effects, and the anticancer activity of aspirin is very modest. Previously, we have demonstrated that the combination of γT with aspirin prolonged the anti-inflammatory activity of aspirin and alleviated aspirin-associated adverse effects in a carrageenan-induced inflammation model in rats. Additionally, we found that the combination of γT and aspirin has stronger anticancer activity than aspirin or γT alone against HCT-116 human colorectal carcinoma cells. Therefore, we examined the anticancer effect of the combination of 0.025% aspirin and 0.05% γT against AOM-induced and DSS-promoted tumorigenesis in mice. In this study, we have found that the combination of aspirin and γT, but not aspirin or γT alone, suppressed colon tumorigenesis in mice, as indicated by 40% and 50% reduction in the multiplicity of total polyps (P < 0.05) and large adenomatous polyps (>2mm2, P < 0.05), respectively. More strikingly, the combination of aspirin and γT reduced the overall tumor area by 60% (P < 0.05). Noteworthy, the supplementation of γT also alleviated aspirin-induced stomach lesion and appeared to modulate intestinal microbial composition. Our study demonstrated that the combination of aspirin and γT has stronger anticancer activity than aspirin or γT alone while alleviates aspirin-associated adverse effect, suggesting that the combination of γT and aspirin is a more effective and safer chemopreventive agent for CRC than aspirin alone.</p>

No description available.

Inflammatory Bowel Disease (IBD) is a chronic and incurable condition that is increasing inprevalence across the globe. This illness consist of two forms: Crohn’s Disease (CD) andUlcerative Colitis (UC). CD is characterised by a patch inflammation pattern across the gut anda multitude of different factors, such as diet. Contemporary research has found a link betweengut dysbiosis and the development of IBD, suggesting that the microbial flora colonising the guthave a vital part to play in the development of CD.This paper aims to identify taxa associated with CD. This is done through the application ofmachine learning algorithms as standard univariate statistical methods fail to apply in the highlyinterdependent domain of the gut microbiome. The compositionally of the data and externalfactors influencing variance in the data will be taken into account.After applying a Center Log ratio transformation (CLR) to a MetaPhlAn3 taxonomic profile andusing a random forest classifier the following five taxa were identified as the most important inthe association to CD: Ruminococcaceae bacterium, Akkermansia muciniphila, Streptococcusparasanguinis, Flavonifractor plautii and Bifidobacterium bifidum.

In the present investigation peripheral blood lymphocytes from patients with inflammatory bowel disease (IBD) and different cancer states were treated with various agents and compared with lymphocytes from healthy control individuals (HCI) treated in the same way and measured in the Comet assay. For inflammatory bowel disease, patient¿s responses in IBD patients treated with H2O2 were higher than in HCI and crohn¿s patients (CD) were found to have higher responses than Ulcerative colitis (UC) patients. The responses for all IBD and HCI were all reduced in the presence of chaga mushroom extract which behaved in an antioxidant manner. A second group of IBD patients were treated with the heterocyclic amine (food mutagen), IQ and H2O2 and responses were reduced in the presence of the flavonoids, quercetin and epicatechin and compared with HCI similarity treated. In all cells responses were reduced with flavonoids and again CD had higher responses than the UC patients and IBD patients higher than HCI. The responses with CD and UC were that confirmed in two independent studies with IBD, one with chaga mushroom extract and the other with flavonoids. Peripheral lymphocytes from malignant melanoma and suspected melanoma patients and colon cancer and polyposis patients were compared to the lymphocytes from HCI and treated with UVA. There were differential sensitivities when measured in the micronucleus and Comet assays. The cancer patients had higher responses than those in the precancerous states and they in turn were higher than responses in HCI. In all the studies, untreated baseline DNA damage values were also higher in IBD and cancer patients and pre-cancerous patients than HCIs. This would suggest that baseline frequencies of different diseases compared to controls could be an important biomarker in the diagnosis of pre-cancers and early stage cancers. Also peripheral lymphocytes are a useful surrogate for cancers and pre-cancerous disease states since, blood is present in all organs and tissues and DNA is basically the same in all cells.

The synthesis of a number of alkyl esters such as methyl lactate, methyl decanoate, and ethyl benzoate via esterification in a reactive distillation is quite challenging. It is due to the complexity in the thermodynamic behaviour of the chemical species in the reaction mixture in addition to the difficulty of keeping the reactants together in the reaction section. One of the reactants (in these esterification reactions) having the lowest boiling point can separate from the other reactant as the distillation continues. This can result in a significant drop in the reaction conversion in a conventional reactive distillation whether it is a batch or a continuous column. To overcome this challenge, new different types of batch reactive distillation column configurations: (1) integrated conventional (2) semi-batch (3) integrated semi-batch (4) integrated dividing-wall batch distillation columns have been proposed here. Four esterification reaction schemes such as (a) esterification of lactic acid (b) esterification of decanoic acid (c) esterification of benzoic acid (d) esterification of acetic acid are investigated here. A detailed dynamic model based on mass, energy balances, chemical reaction, and rigorous thermodynamic (chemical and physical) properties is considered and incorporated in the optimisation framework within gPROMS (general PROcess Modelling System) software. It is found that for the methyl lactate system, the i-SBD operation outperforms the classical batch operations (CBD or SBD columns) to satisfy the product constraints. While, for the methyl decanoate system, the i-DWCBD operation outperforms all CBD, DWBD and sr-DWBD configurations by achieving the higher reaction conversion and the maximum product purity. For the ethyl benzoate system, the performance of i-CBD column is superior to the CBD process in terms of product quality, and conversion rate of acid. The CBD process is found to be a more attractive in terms of operating time saving, and annual profit improvement compared to the IBD, and MVD processes for the benzyl acetate system. / The Higher Committee for Education Development in Iraq (HCED)

Die niedrige Inzidenz chronisch-entzündlicher Darmerkrankungen (CED) in ostasiatischen Ländern im Vergleich zu Westeuropa und den USA könnte auf unterschiedliche Lebensstile und Ernährungsgewohnheiten zurückzuführen sein. Asiaten nehmen mit der Nahrung viel höhere Mengen an Isoflavonen zu sich als Europäer und US-Amerikaner. Diese sind in der Lage, wie natürliche Östrogene an Östrogenrezeptoren (ER) zu binden. Für das Östrogen 17β-Östradiol (E2) sowie selektive Liganden des ERβ sind antiinflammatorische Wirkungen im Darm bereits nachgewiesen worden. Diese Arbeit untersuchte in Modellsystemen für CED die antiinflammatorischen Eigenschaften von Isoflavonen, speziell von Genistein, und stellte einen Vergleich mit synthetischen ER-selektiven Liganden sowie E2 her, um die Involvierung der beiden ER-Subtypen zu evaluieren. In tierexperimentellen Studien wurde der Einfluss der Testsubstanzen auf Ausprägung und Verlauf einer Kolitis in zwei Nagermodellen (HLA-B27 transgene Ratte und TNBS-induzierte Kolitis) analysiert. Ein Ernährungsexperiment, in dem eine Gruppe der Tiere bereits in utero sowie postnatal über Muttermilch und Futter hohen Phytoöstrogenspiegeln ausgesetzt war, zeigte wider Erwarten keine antiinflammatorischen Effekte auf die akute Ausprägung der induzierten Kolitis. Stattdessen waren die untersuchten Parameter bei dieser Ernährungsform gegenüber prä- und postnatal normal ernährten Tieren verstärkt. Dagegen bewirkte oral verabreichtes Genistein in der chronischen Phase der TNBS-induzierten Kolitis eine Unterdrückung der Entzündungsparameter im Darm. Die subkutane Verabreichung von Genistein, eines steroidalen ERβ-selektiven Agonisten, oder von E2 führte hingegen zu keiner signifikanten Einflussnahme auf die untersuchten Parameter in der akuten Phase der Inflammation. Zur Charakterisierung der molekularen Grundlagen einer antiinflammatorischen Wirkung von E2, synthetischen ER-selektiven Agonisten und Genistein wurden in vitro Studien mit Kolonkarzinomzelllinien (HT-29 und Caco-2) durchgeführt. Hierzu wurden die Zellen mit Interleukin-1β (IL-1β) stimuliert, was eine Induktion der inflammationsassoziierten Gene Cyclooxygenase-2 und Interleukin-6 auf mRNA Ebene bewirkte. Bis auf Genistein konnten für die getesteten Substanzen keine antiinflammatorischen Effekte auf die mRNA-Expression der induzierten Markergene beobachtet werden. Genistein bewirkte in Caco-2 Zellen eine Hemmung der untersuchten Gene. Weitere Analysen ergaben, dass die beiden Zelllinien ER nur schwach bzw. gar nicht exprimieren. Eine Transfektion von HT-29 Zellen mit ERα führte zu einer deutlichen Hemmung der Expression der Markergene durch E2, während eine Transfektion mit ERβ lediglich einen schwach hemmenden Effekt bewirkte. Die Ergebnisse der vorliegenden Arbeit legen nahe, dass die niedrigen CED-Inzidenzraten in Ostasien wohl nicht allein auf dem dortigen hohen Isoflavonkonsum beruhen, sondern auch anderen Komponenten des Lebensstils zuzuschreiben sind. Dennoch deutet sich an, dass das Genistein, bei oraler Administration, die Regeneration des geschädigten Darmgewebes im chronischen Erkrankungsverlauf unterstützen und damit auch zur Prävention von Kolonkarzinomen beitragen könnte. Bei antiinflammatorischen Effekten von ER-Liganden spielt die Transaktivierung von ER eine entscheidende Rolle. Die Wirkung von Genistein in untransfizierten Caco-2 Zellen legt jedoch auch die Teilnahme weiterer Mechanismen nahe, die noch zu untersuchen sind. Vor diesem Hintergrund erscheinen weiterführende Untersuchungen zum Einsatz von steroidalen ER-Agonisten und Genistein bei CED und den zugrunde liegenden Mechanismen als sinnvoll.

Understanding of chronic sequelae development after infection with foodborne pathogens is limited and an increased understanding could assist with the development of more accurate burden of disease estimates. The purpose of this thesis was to determine via systematic review and meta-analysis of the published international literature, the proportion of cases of Salmonella, Campylobacter and E. coli O157 that will develop the chronic sequelae of reactive arthritis, haemolytic uraemic syndrome, irritable bowel syndrome, inflammatory bowel disease or Guillain Barré syndrome. This information can be used to increase our understanding of the relationship between infection and the development of long term health complications while providing a key piece of information for the development of accurate burden of disease estimates. / Canadian Institutes of Health Research Institute of Population and Public Health/Public Health Agency of Canada, Applied Public Health Research Chair (awarded to Jan M. Sargeant)

La clairance des cellules apoptotiques par les macrophages est à l’origine d’un microenvironnement pro-résolutif composé de différents facteurs solubles, permettant de stopper la réaction inflammatoire et d’engager la réparation tissulaire. La résolution de l’inflammation est parfois défaillante et concourt au développement de pathologies inflammatoires chroniques, comme les maladies inflammatoires chroniques de l’intestin (MICI), qui regroupent la maladie de Crohn (MC) et la rectocolite hémorragique (RCH). Dans ce contexte, nous proposons d’évaluer l’efficacité thérapeutique de l’injection de ces facteurs pro-résolutifs dans le traitement des MICI. Ce produit issu de la culture de macrophages avec des cellules apoptotiques, appelé SuperMApo (Supernatant issued from Macrophage Apoptotic cell culture) (Brevet # WO2014106666-A1, 2013) contient des facteurs pro-résolutifs semblables à ce qu’on retrouve dans le processus physiologique de résolution de l’inflammation, et qui peuvent être absents ou inefficaces chez ces patients.Lors de ce travail, nous avons mise en évidence une efficacité thérapeutique de SuperMApo à l’aide de deux modèles expérimentaux de colite. Pour évaluer la pertinence de ces modèles par rapport à la pratique clinique, nous avons mise en place la vidéo-endoscopie souple. On a montré que l’efficacité de SuperMApo se traduit par diminution du score clinique, endoscopique et histologique des souris colitiques, accompagnée d’une amélioration de la perméabilité intestinale, et de la cicatrisation muqueuse. Cette efficacité thérapeutique est liée en partie à une reprogrammation des cellules présentatrices d’antigènes (APC) notamment de cDC et de macrophages qui présentent moins de réponse aux ligands de TLR, favorisent l’induction de Treg et inhibent la production de Th1. Par ailleurs, SuperMApo induit une cicatrisation nette de la muqueuse intestinale associée à la fois à une activation des myofibroblastes (la forme active des fibroblastes) et des cellules intestinales épithéliales (IEC). Concrètement, SuperMApo augmente les propriétés de migration, de prolifération et de cicatrisation de ces deux types cellulaire. Cet effet dépend en partie des facteurs de croissance au sein de SuperMApo comme le TGF-β, l’IGF-I et le VEGF. Finalement des résultats préliminaires montrent que SuperMApo induit un profil réparateur sur des fibroblastes issus de patients atteints de MICI. L’ensemble de ces résultats montrent, que l’injection de ces facteurs pro-résolutifs permet de mettre en œuvre des mécanismes capables de mettre en place un processus de résolution de l’inflammation et ouvre vers une utilisation clinique de cette approche dans le traitement de MICI. / Inflammation is a natural body defence reaction in response to injuries. The clearance of apoptotic cells by macrophages is at the origin of a pro-resolving microenvironment composed of various soluble factors, allow the arrest of the inflammatory response and to initiate tissue repair. The resolution of inflammation is sometimes defective and contributes to the development of chronic inflammatory diseases, such as chronic inflammatory bowel disease (IBD), which include Crohn's disease (CD) and ulcerative colitis (UC). In this context, we propose to evaluate the therapeutic effect of these pro-resolving factors in the treatment of IBD. This factors derived from the culture of macrophages with apoptotic cells, and called SuperMApo (Supernatant issued from Macrophage Apoptotic cell culture) (Patent # WO2014106666-A1, 2013) contains pro-resolving factors similar to those found in the physiological process of inflammatory resolution, and which may be absent or ineffective in these patients.In this work, we have demonstrated the therapeutic effect of SuperMApo using two experimental models of colitis. To assess the relevance of these models to clinical practice, we have implemented flexible video endoscopy. The therapeutic effect of SuperMApo has been shown to decrease the clinical, endoscopic and histological score of colitis mice, accompanied by improved intestinal permeability and mucosal healing in vivo. This therapeutic effect is related in part to reprogramming of antigen presenting cells (APC), in particular cDC and macrophages, which exhibit less response to TLR ligands, promote induction of Treg and inhibit Th1 production. In addition, SuperMApo induces a marked tissue repair of the intestinal mucosa associated with activation of myofibroblasts, the active form of fibroblasts, and the epithelial intestinal cells (IEC). In particular, SuperMApo increases the migration, proliferation and wound healing properties of these two cell types. This effect depends in part on the growth factors contained in SuperMApo such as TGF-β, IGF-I and VEGF. Finally, preliminary results show that SuperMApo induces a repairing state on fibroblasts from patients with IBD. This opens widely the use of SuperMApo as a clinically approach to propose this new therapeutic option to refractory patients suffering from IBD

Les inhibiteurs des protéases à sérine (Serpins) constituent une classe d'enzymes très peu étudiée chez les bactéries. Dans ce travail de thèse nous nous sommes intéressés à l'étude des serpins provenant du microbiote intestinal et l'investigation de leur potentiel anti-inflammatoire pour le traitement des maladies inflammatoires chroniques de l'intestin (MICI) chez l'homme. Pour cela nous avons identifié les serpins provenant du microbiote intestinal humain et analysé leur diversité ainsi que leur distribution entre les individus malades et sains. Ces données nous ont permis d'isoler les serpins significativement associées aux MICI. La purification de quarte d'entre elles nous a amené à démontrer qu'elles inhibent les protéases humaines impliquées dans les MICI. L'analyse biochimique et cinétique approfondie de ces protéines a montré qu'elles possèdent des propriétés originales notamment leur efficacité d'inhibition élevée. L'étude de l'effet protecteur de trois serpins chez un modèle animal de colite a démontré pour la première fois l'efficacité des serpins in vivo démontrant ainsi leur potentiel thérapeutique. / Serine protease inhibitors (Serpins) are a class of proteins that reamin poorly studied in bacteria. In this thesis we are interested in the study of serpins originating from the intestinal microbiota and the investigation of their anti-inflammatory potential for the treatment of inflammatory bowel diseases (IBD) in humans. For this we have identified serpins from the human gut microbiota and analyzed their diversity as well as their distribution between healthy and IBD patients. These data allowed isolating serpins significantly associated with IBD. The purification of four of them led us to demonstrate that they inhibit human proteases involved in IBD. Biochemical and kinetic analysis of these proteins showed that they exhibit original properties, in particular their high inhibition efficiency. The study of the protective effect of three serpins in an animal model of colitis demonstrated for the first time the efficacy of serpins in vivo demonstrating thus their therapeutic potential.

<p dir="ltr">The gastrointestinal (GI) tract and its diverse microbial community play a significant role in overall health, impacting various aspects such as metabolism, physiology, nutrition, and immune function. Disruptions in the gut microbiota have been associated with metabolic diseases, colorectal cancer, diabetes, obesity, inflammatory bowel disease, Alzheimer's disease, and depression. Despite recognizing the importance of the gut microbiota, the interrelationship between microbiota, diet, and disease prevention remains unclear. Current techniques for monitoring the microbiome often rely on fecal samples or invasive endoscopic procedures, limiting the understanding of spatial variations in the gut microbiota and posing invasiveness challenges. To address these limitations, this dissertation focuses on the design and development of an electronic-free smart capsule platform capable of targeted sampling of GI fluid within specific regions of the GI tract. The capsule can be retrieved for subsequent bacterial culture and sequencing analysis. The capsule design is based on stimuli-responsive polymers and superabsorbent hydrogels, chosen for their proven safety, compatibility, and scalability. By leveraging the pH variation across the GI tract, the pH-sensitive polymeric coatings dissolve at the desired region, activating the sampling process. The superabsorbent hydrogel inside the capsule collects the sampled GI fluid and facilitates capsule closure upon completion of sampling. Systematic studies were conducted to identify suitable pH-responsive polymer coatings, superabsorbent hydrogels, and processing conditions that effectively operated within the physiological conditions of the GI tract. The technology's effectiveness and safety were validated through rigorous <i>in vitro</i> and <i>in vivo</i> studies using pig models. These studies demonstrated the potential of the technology for targeted sampling of GI fluid in both small and large intestinal regions, enabling subsequent bacterial culture and gene sequencing analysis. Additionally, the capsule design was enhanced with the integration of a metal tracer, enabling traceability throughout the GI tract using X-ray imaging and portable metal detectors for ambulatory screening. This technology holds promise as a non-invasive tool for studying real-time metabolic and molecular interactions among the host, diet, and microbiota in challenging-to-access GI regions. Its application in clinical studies can provide new insights into diet-host-microbiome interactions and contribute to addressing the burden faced by patients and their families dealing with GI-related diseases.</p>