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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Efeitos dos diferentes ácidos graxos no metabolismo lipídico e estresse oxidativo em camundongos C57/BL alimentados com dieta hiperlipídica e rica em frutose / Effects of different fatty acids on lipid metabolism and oxidative stress in C57/BL mice fed a high fat diet and rich in fructose

Manca, Camila Sanches 30 June 2017 (has links)
A esteatose hepática não alcóolica está relacionada às causas crescentes de morbimortalidade de doenças hepáticas. Sua incidência está relacionada à obesidade e comorbidades vinculadas a esta, na qual tem despertado grande interesse na pesquisa. A modulação quantitativa da dieta pode promover ou retardar a patologia. Desta forma, terapias voltadas para retardar ou diminuir a esteatose hepática não alcóolica poderiam atenuar o dano hepático, melhorar a função hepática e reduzir sua progressão. Os objetivos do presente estudo foram: avaliar o consumo de óleos vegetais ricos em MUFAs e PUFAs usados comercialmente na prevenção ou redução da esteatose hepática analisando parâmetros do metabolismo lipídico hepático e sérico, estresse oxidativo e retardando a progressão de NAFLD. Material e Métodos: os animais foram divididos nos seguintes grupos: Controle (n=10) + HLF * (n=10); Grupo HLF * AZ (n=10); Grupo HLF* CN (n=10); Grupo HLF* S (n=10). Após 16 semanas de dieta e tratamento com os respectivos óleos, os animais foram anestesiados e o sangue retirado por punção cardíaca e os tecidos para as análises posteriores. Resultados: A oferta de uma dieta rica em gordura saturada (banha) + frutose ocasionou um aumento do peso no grupo HLF enquanto a administração dos respectivos óleos vegetais foi capaz de retardar o ganho de peso. O peso hepático e da soma dos tecidos adiposos epididimal e retroperitonial foi maior no HLF enquanto houve redução significativa no peso hepático HLF/S. O tecido retroperitonial foi menor no HLF/CN. De uma maneira geral o tratamento com os respectivos óleos vegetais diminui a esteatose em todos os grupos experimentais. A oferta de azeite extra virgem não refletiu no ganho de peso, porém o grupo teve um aumento significativo de TG e VLDL séricos, com diminuição do colesterol sérico. Avaliado histologicamente diminuiu o score de esteatose quando comparado ao HLF sendo classificado como esteatose macro e microvesicular de leve a moderada. O óleo de soja apresentou uma maior quantidade de PUFAs, sendo rico em n-6, refletiu na manutenção do peso dos animais, diminuiu a esteatose, sendo classificado como esteatatose leve, quando comparado ao HLF, porém aumentou o colesterol sérico. Apresentou um aumento de MDA e diminuição de GSH hepático. O óleo de canola devido a seu teor em ácidos graxos PUFAs (n-6 e n-3) teve maior incorporação do EPA e DHA que parecem ter evidenciado positivamente. Não apresentou alteração nos parâmetros bioquímicos e apresentou menor acúmulo de gordura hepática através da análise do percentual de gordura hepática e histopatologia, sendo caracterizado como esteatose leve. Pela peroxidação lipídica apresentou um maior acúmulo de MDA, porém um aumento de GSH. Contudo, a oferta dos respectivos óleos influenciou positivamente em diferentes mecanismos fisiológicos. / The Non-alcoholic fatty liver is related to the increasing causes of morbidity and mortality of liver diases. Its incidence is related to obesity and comorbidities linked to it, in which it has awaked great interest in the research. The disease is associated to genetic predisposition, lack of physical activity and high intake of saturated fats and fructose. Quantitative modulation of the diet may promote or retard the pathology. Thus, therapies aimed at delaying or decreasing non alcoholic hepatic steatosis could alleviate liver damage, improve liver function and reduce its progression. The objectives of the present study were: to evaluate the consumption of vegetable oils rich in commercially available MUFAs and PUFAs in the prevention or reduction of hepatic steatosis by analyzing parameters of hepatic and serum lipid metabolism, oxidative stress and delaying the progression of NAFLD. Material and Methods: animals were divided into the following groups: Control (n = 10) + HLF * (n = 10); Group HLF * AZ (n = 10); Group HLF * CN (n = 10); Group HLF * S (n = 10). After 16 weeks of diet and treatment with the respective oils, the animals were anesthetized and blood was withdrawn by cardiac puncture and tissues for further analysis. Results: The supply of a diet rich in saturated fat (lard) + fructose caused an increase in weight in the HLF group while the administration of the respective vegetable oils was able to delay the weight gain. Liver weight and sum of epididymal and retroperitoneal adipose tissues were higher in HLF while there was a significant reduction in HLF / S hepatic weight. Retroperitoneal tissue was lower in HLF / CN. In general, treatment with the respective vegetable oils decreases steatosis in all experimental groups. The supply of extra virgin olive oil did not reflect weight gain, but the group had a significant increase in serum TG and VLDL, with a decrease in serum cholesterol. Histologically it reduced the steatosis score when compared to the HLF being classified as mild to moderate macro and microvesicular steatosis. Soybean oil presented a higher amount of PUFAs, being rich in n-6, reflected in the maintenance of animal weight, decreased steatosis, being classified as mild steatosis when compared to HLF, but increased serum cholesterol. He presented an increase of MDA and decrease of hepatic GSH. Canola oil due to its content of PUFAs (n-6 and n-3) had greater incorporation of EPA and DHA than appear to have been positively evidenced. There was no alteration in the biochemical parameters and presented lower accumulation of liver fat through the analysis of the percentage of liver fat and histopathology, being characterized as mild steatosis. By the lipid peroxidation presented a greater accumulation of MDA, but an increase of GSH. However, the supply of the respective oils had a positive influence on different physiological mechanisms.
12

Efeitos dos diferentes ácidos graxos no metabolismo lipídico e estresse oxidativo em camundongos C57/BL alimentados com dieta hiperlipídica e rica em frutose / Effects of different fatty acids on lipid metabolism and oxidative stress in C57/BL mice fed a high fat diet and rich in fructose

Camila Sanches Manca 30 June 2017 (has links)
A esteatose hepática não alcóolica está relacionada às causas crescentes de morbimortalidade de doenças hepáticas. Sua incidência está relacionada à obesidade e comorbidades vinculadas a esta, na qual tem despertado grande interesse na pesquisa. A modulação quantitativa da dieta pode promover ou retardar a patologia. Desta forma, terapias voltadas para retardar ou diminuir a esteatose hepática não alcóolica poderiam atenuar o dano hepático, melhorar a função hepática e reduzir sua progressão. Os objetivos do presente estudo foram: avaliar o consumo de óleos vegetais ricos em MUFAs e PUFAs usados comercialmente na prevenção ou redução da esteatose hepática analisando parâmetros do metabolismo lipídico hepático e sérico, estresse oxidativo e retardando a progressão de NAFLD. Material e Métodos: os animais foram divididos nos seguintes grupos: Controle (n=10) + HLF * (n=10); Grupo HLF * AZ (n=10); Grupo HLF* CN (n=10); Grupo HLF* S (n=10). Após 16 semanas de dieta e tratamento com os respectivos óleos, os animais foram anestesiados e o sangue retirado por punção cardíaca e os tecidos para as análises posteriores. Resultados: A oferta de uma dieta rica em gordura saturada (banha) + frutose ocasionou um aumento do peso no grupo HLF enquanto a administração dos respectivos óleos vegetais foi capaz de retardar o ganho de peso. O peso hepático e da soma dos tecidos adiposos epididimal e retroperitonial foi maior no HLF enquanto houve redução significativa no peso hepático HLF/S. O tecido retroperitonial foi menor no HLF/CN. De uma maneira geral o tratamento com os respectivos óleos vegetais diminui a esteatose em todos os grupos experimentais. A oferta de azeite extra virgem não refletiu no ganho de peso, porém o grupo teve um aumento significativo de TG e VLDL séricos, com diminuição do colesterol sérico. Avaliado histologicamente diminuiu o score de esteatose quando comparado ao HLF sendo classificado como esteatose macro e microvesicular de leve a moderada. O óleo de soja apresentou uma maior quantidade de PUFAs, sendo rico em n-6, refletiu na manutenção do peso dos animais, diminuiu a esteatose, sendo classificado como esteatatose leve, quando comparado ao HLF, porém aumentou o colesterol sérico. Apresentou um aumento de MDA e diminuição de GSH hepático. O óleo de canola devido a seu teor em ácidos graxos PUFAs (n-6 e n-3) teve maior incorporação do EPA e DHA que parecem ter evidenciado positivamente. Não apresentou alteração nos parâmetros bioquímicos e apresentou menor acúmulo de gordura hepática através da análise do percentual de gordura hepática e histopatologia, sendo caracterizado como esteatose leve. Pela peroxidação lipídica apresentou um maior acúmulo de MDA, porém um aumento de GSH. Contudo, a oferta dos respectivos óleos influenciou positivamente em diferentes mecanismos fisiológicos. / The Non-alcoholic fatty liver is related to the increasing causes of morbidity and mortality of liver diases. Its incidence is related to obesity and comorbidities linked to it, in which it has awaked great interest in the research. The disease is associated to genetic predisposition, lack of physical activity and high intake of saturated fats and fructose. Quantitative modulation of the diet may promote or retard the pathology. Thus, therapies aimed at delaying or decreasing non alcoholic hepatic steatosis could alleviate liver damage, improve liver function and reduce its progression. The objectives of the present study were: to evaluate the consumption of vegetable oils rich in commercially available MUFAs and PUFAs in the prevention or reduction of hepatic steatosis by analyzing parameters of hepatic and serum lipid metabolism, oxidative stress and delaying the progression of NAFLD. Material and Methods: animals were divided into the following groups: Control (n = 10) + HLF * (n = 10); Group HLF * AZ (n = 10); Group HLF * CN (n = 10); Group HLF * S (n = 10). After 16 weeks of diet and treatment with the respective oils, the animals were anesthetized and blood was withdrawn by cardiac puncture and tissues for further analysis. Results: The supply of a diet rich in saturated fat (lard) + fructose caused an increase in weight in the HLF group while the administration of the respective vegetable oils was able to delay the weight gain. Liver weight and sum of epididymal and retroperitoneal adipose tissues were higher in HLF while there was a significant reduction in HLF / S hepatic weight. Retroperitoneal tissue was lower in HLF / CN. In general, treatment with the respective vegetable oils decreases steatosis in all experimental groups. The supply of extra virgin olive oil did not reflect weight gain, but the group had a significant increase in serum TG and VLDL, with a decrease in serum cholesterol. Histologically it reduced the steatosis score when compared to the HLF being classified as mild to moderate macro and microvesicular steatosis. Soybean oil presented a higher amount of PUFAs, being rich in n-6, reflected in the maintenance of animal weight, decreased steatosis, being classified as mild steatosis when compared to HLF, but increased serum cholesterol. He presented an increase of MDA and decrease of hepatic GSH. Canola oil due to its content of PUFAs (n-6 and n-3) had greater incorporation of EPA and DHA than appear to have been positively evidenced. There was no alteration in the biochemical parameters and presented lower accumulation of liver fat through the analysis of the percentage of liver fat and histopathology, being characterized as mild steatosis. By the lipid peroxidation presented a greater accumulation of MDA, but an increase of GSH. However, the supply of the respective oils had a positive influence on different physiological mechanisms.
13

Fractionnement par cristallisation extractive à froid des acides gras libres et des triglycérides de l'huile de Nephelium Lappaceum L. (Ramboutan) : oxygénation et enrichissement en acides gras particuliers / New crystallization separation and densification processes of saturated and monounsaturated fatty acids by gelation / degelling of saturated fatty acids and allylic hydroperoxidation of monounsaturated fatty acids of Nephelium Lappaceum L. oil (Rambutan)

Douniama-Lonn, Gré Véronique 17 November 2018 (has links)
Dans cette étude, les fruits du Nephelium Lappaceum L. (ramboutan) ont été récoltés en Mars 2015 à Boko, dans la zone sud de la République du Congo. Plante à graines oléagineuses avec un noyau riche en huile (36 %), particulièrement composée d’acides gras saturés et monoinsaturés à longues chaines : C16:0 4,84 %, C18:0 5,48 %, C18:1 45,62 %, C18:2 2,70 %, C20:0 26,53 %, C20:1 9,27 % et C22:0 2,64 %. L’huile de ramboutan a été hydrolysée par voie enzymatique en présence de lipase Candida rugosa, les acides gras libres sont obtenus avec un ratio acides gras saturés (AGS)/acides gras monoinsaturés (AGI) de 0,67. La disponibilité des acides gras saturés et monoinsaturés des familles en C20 et C22 a stimulé nos investigations vers l’élaboration des shortenings et biotensioactifs à haut point de fusion. Deux stratégies ont été mises en place à partir des concentrats en acides gras libres issus de l’hydrolyse enzymatique de l’huile de ramboutan en présence de lipase de Candida rugosa. La première a consisté à la cristallisation à froid des acides gras saturés par la technologie de gélification/dégélification. On observe à l’issu de ce procédé une séparation physique du mélange d’acides gras en deux fractions. Une étude thermique des fractions solide et fluide a été effectuée et a montré que les AGS (To = 15, 86 °C ; Tf = 18,49 °C) refroidissent plus vite, mais fondent moins vite que les AGI (To = -19, 46 °C, Tf= 3,87 °C). Les teneurs des AGI passent de 55,6 % après hydrolyse à 63,53 % dans la fraction fluide et celles des AGS passent de 39,1 % après hydrolyse à 45,13 %. Les résultats de la SFC indique une teneur en AGS de 25,98 % dans la fraction fluide mais de 38,24 % dans la fraction solide ; Et le rendement massique de la fraction fluide passent de 16% à 55 % et de 84 % à 45 % respectivement de la fraction fluide et la fraction solide. La deuxième stratégie a consisté à réaliser l'insertion allylique de l'oxygène singulet dans les acides gras libres monoinsaturés à longues chaines C18:1 et C20:1. Elle est réalisée dans un milieu émulsionné constitué d'un système multiphase NaOH/H2O2/Na2MoO4. Le produit de réaction, au moyen de la GC, montre la présence des acides gras non conventionnels, deux isomères d’hydroperoxydes d’acides gras respectifs de chaque AGMI (C18:1 et C20:1) de conformation trans. Il en résulte une augmentation de la teneur en acides gras saturés à longues chaines C20: 0 (26,21% à 56,46%) et C22 (2,48 % à 3,77 %). Le produit de cette réaction présente un ratio AGS/ AGT (acides gras totaux): 0,82. La valorisation séquencée des acides gras de l'huile de noyau de ramboutan permet de proposer deux plateformes de biomolécules shortenings à haut point de fusion: Une plateforme de composition bien définie en acides gras saturés C20:0 et C22:0 et une autre constituée par un bulk en acides gras saturés C20:0-C22:0 et acides gras insaturés monohydroxyperoxydés trans. Les investigations sur l'hydroperoxydation des acides gras insaturés ont révélé un intérêt particulier sur l'impact du radical hydroxy peroxyde sur le mouvement de la configuration trans et cis dans ces acides gras modifiés en présence de glycidol en monoesters de glycérol et d'acides gras hydroxy peroxydes insaturés cis. C'est une autre plateforme de synthèse originale de biotensioactifs hydroxy peroxydes insaturés cis nouveaux qu'offre la valorisation séquencée des concentrats d'acides gras insaturés de l'huile de ramboutan. / In this study, the fruits of Nephelium Lappaceum L. (Rambutan) were harvested in Boko, in the southern area of the Republic of Congo. Oilseed plant with an oil-rich core (36 %), particularly composed of long chain fatty acids: C16:0 4.84 %, C18:0 5.48 %, C18:1 45.62 %, C18:2 2.70 %, C20:0 26.53 %, C20:1 9.27 % and C22:0 2.64 %. Rambutan oil was hydrolyzed enzymatically in the presence of lipase Candida rugosa, the free fatty acids are obtained with a ratio of saturated fatty acids (AGS)/monounsaturated (AGI) of 0.67. The availability of saturated and monounsaturated fatty acids of the C20 and C22 families stimulated our investigations towards the development of shortenings and biotensioactives with a high melting point. Two strategies have been implemented using free fatty acid concentrates derived from the enzymatic hydrolysis of rambutan oil in the presence of Candida rugosa lipase. The first was to achieve the cold crystallization of saturated fatty acids by gelation / defrosting technology. At the end of this process, a physical separation of the fatty acid mixture into two fractions is observed. A thermal study of the solid and fluid fractions was carried out and showed that the AGS (To = 15, 86 °C, Tf = 18.49 °C) cool faster, but melt slower than the AGI (To = -19 46 °C, mp = 3.87 °C). The contents go from 55.6% after hydrolysis to 63.53 % of AGI in the fluid fraction and 39.1 % after hydrolysis to 45.13 % of AGS. The results of the SFC indicate an AGS content of 25.98 % in the fluid fraction but of 38.24 % in the solid fraction ; And the mass yield of 16 % to 55 % and 84 % to 45 % respectively of the fluid fraction (enriched in AGI, in particular in MUFA) and the solid fraction (enriched with AGS). The second strategy was to perform the allyl insertion of singlet oxygen in long-chain monounsaturated free fatty acids C18:1 and C20:1, carried out in an emulsified medium consisting of a multiphase NaOH / H2O2/Na2MoO4 system. The reaction product, using GC, shows the presence of unconventional fatty acids, two isomers of respective fatty acid hydroperoxides of each trans-conforming MUFA (C18:1 and C20:1) and an increase in saturated fatty acids content with long chain C20:0 (26.21 % to 56.46 %) and C22:0 (2.48 % to 3.77 %). The product of this reaction has an AGS/AGT ratio of 0.82. The sequential evaluation of the fatty acids of the Ramboutan core oil makes it possible to propose two platforms of biomolecules shortenings with a high melting point: A platform with a well defined composition of saturated fatty acids C20:0 and C22:0 and another constituted by a bulk of C20:0-C22:0 saturated fatty acids and transmonohydroxyperoxide trans unsaturated fatty acids. Investigations on the hydroperoxidation of unsaturated fatty acids have revealed a particular interest on the impact of hydroxyperoxide radical on the movement of the trans and cis configuration in these fatty acids modified in the presence of glycidol in monoesters of glycerol and hydroxyperoxide fatty acids unsaturated cis. This is another novel synthesis platform of new cis-unsaturated hydroxyperoxyd biotensiatives offered by the sequenced recovery of unsaturated fatty acid concentrates from rambutan oil.
14

Molecular mechanisms involved in the protective effect of Mediterranean diet and olive oil consumption in humans

Konstantinidou, Valentini 22 March 2010 (has links)
The scope of the present work was to investigate whether the protective role of the traditional Mediterranean diet (TMD), and virgin olive oil (VOO) rich in phenolic compounds (PC), towards cardiovascular disease can be mediated through gene expression changes. Two trials were performed to assess the in vivo nutrigenomic effects of TMD and VOO in healthy volunteers. The results point out: a) significant gene expression changes of those genes related with cardiovascular-risk processes after VOO ingestion; b) a down-regulation in the expression of atherosclerosis-related genes after a 3-month intervention with a TMD; and c) an olive oil PC health-protective nutrigenomic effect within the frame of the TMD. Changes in gene expression were concomitant with decreases in oxidative damage and systemic inflammation markers. Data from our studies provide further evidence to recommend both the TMD and the VOO as a useful tool for the prevention of atherosclerosis. / El objetivo de este estudio es investigar si el papel protector de la dieta Mediterránea tradicional (TMD) y del aceite de oliva virgen (VOO), rico en compuestos fenólicos (PC), puede ser mediado a través de cambios en la expresión génica. Se realizaron dos ensayos clínicos para evaluar los efectos nutrigenómicos de la TMD y del VOO, in vivo, en voluntarios sanos. Los resultados mostraron a) cambios en la expresión génica de genes relacionados con el riesgo cardiovascular tras la ingestión del aceite virgen de oliva, b) una infra-expresión en la expresión de genes relacionados con el proceso aterosclerótico tras una intervención con TMD de 3 meses y c) que los compuestos fenólicos del aceite de oliva ejercen un efecto nutrigenómico protector en el marco de la TMD. Los cambios en la expresión génica fueron coherentes.

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