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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.
61

Avaliação dos efeitos do oleo extraido dos grãos verdes de Coffea arabica L. e dos fitoesterois de Brassica campestris L na melhora da celulite e da gordura localizada / Study of the effects obtained with the oil extracted from the green seeds of Coffea arabica L. and phytoesterols of Brassica campestris L. in the cellulite improvement

Pereda, Maria Del Carmen Velazquez 13 August 2018 (has links)
Orientador: Mary Luci de Souza Queiroz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T23:46:23Z (GMT). No. of bitstreams: 1 Pereda_MariaDelCarmenVelazquez_D.pdf: 4069355 bytes, checksum: 2eba0c803662fe7e920cab4f907dc527 (MD5) Previous issue date: 2009 / Resumo: Clinicamente, a celulite é definida como uma alteração na topografia da pele que ocorre principalmente em mulheres, na região pélvica, abdômen e membros inferiores, caracterizando-se pelo aspecto de "casca de laranja". Etiologicamente, celulite é definida como uma desordem metabólica localizada do tecido subcutâneo que provoca uma alteração na forma corporal, onde muitas estruturas são alteradas na derme, na micro circulação e, também, no tecido adiposo. Este fenômeno, por sua vez, está associado com modificações morfológicas, histoquímicas e bioquímicas na pele e resultam nas alterações que levam ao desconforto estético e à aparência clínica da celulite. Partes destas alterações decorrem do acúmulo de lipídeos no interior de adipócitos, células chave no equilíbrio lipólise-lipogênese, o qual é visto hoje como uma unidade glandular funcional capaz de promover uma relação direta com o sistema nervoso central. Pesquisas atuais indicam que a busca por substâncias capazes de promover a homeostase dermo-hipodérmica através de uma ação lipolítica direta, aliada ao estímulo da produção de fatores de crescimento, especialmente TGF-? e GM-CSF, bem como de proteínas da matriz extracelular, como colágeno, elastina e GAGs, além de substâncias reguladoras do metabolismo adipocitário. Tendo em vista a complexidade clínica e estética da celulite, bem como as alterações bioquímicas dérmicas e hipodérmicas, buscamos neste trabalho avaliar os efeitos da associação entre o extrato oleoso dos grãos verdes de café (Coffea arabica L.) (OC) e os fitoesteróis de canola (Brassica campestris L.) (F), cuja combinação resulta no produto Slimbuster® L (SBL). Para isto, avaliamos neste estudo os efeitos in vitro (fibroblastos e adipócitos humanos), ex-vivo (fragmentos de pele humana) e clínicos (voluntários humanos) de SBL, OC e/ou F, utilizando metodologias e modelos experimentais que possibilitassem a visão global do processo celulítico. Os resultados demonstram que SBL foi capaz de estimular significativamente a lipólise, a síntese de leptina em cultura de adipócitos humanos, a produção de GM-CSF, TGF-?, colágeno, elastina e GAGs em cultura de fibroblastos humanos, a contração de fibroblastos em gel de colágeno, bem como promover a melhora das características histológicas gerais da pele (ex-vivo). As frações isoladas (OC e F) também demonstraram efeitos importantes e distintos, sendo estes mais pronunciados para OC e potencializados quando ambos são associados (SBL). Os resultados clínicos demonstram que o produto Slimbuster® L foi bem apreciado pelas voluntárias quanto aos itens "facilidade de aplicação", "pele mais lisa" e "pele mais macia", "atenuação de celulite" e "redução de gordura", especialmente após 60 dias de utilização de uma loção corporal contendo 3,0% (p/p) do produto. Os resultados das medidas instrumentais obtidos demonstram que o produto foi capaz de reduzir significativamente as medidas na região da coxa (superior, mediana e inferior), sendo esta diminuição centimétrica observada em aproximadamente 30% do painel em D30 e em 50% do painel em D60. As demais áreas avaliadas - abdome, pernas e quadris - não apresentaram significância estatística, porém devem ser levadas em consideração, pois apresentaram forte tendência após 60 dias de aplicação da loção corporal, indicando uma possível melhora significativa com o uso prolongado. A análise adipométrica das voluntárias demonstrou também forte tendência de redução da taxa de gordura localizada nas regiões do abdome, supra-ilíaca, supra-espinal e coxa proximal. A espessura da hipoderme através da ultrassonografia (ecografia) possibilitou observar uma redução superior a 2% nas regiões da coxa e abdome em aproximadamente 70% do painel em todos os tempos experimentais avaliados (D30 e D60). De acordo com todos os resultados obtidos neste trabalho, podemos concluir que o produto Slimbuster® L pode ser considerada uma ferramenta segura e eficaz na prevenção e tratamento tópico da gordura localizada e celulite / Abstract: Cellulite is an alteration of the topography of the skin that occurs mainly in women on the pelvic region, lower limbs and abdomen. It is characterized by a padded or 'orange peel' appearance. In according with its etiology, cellulite is defined as a metabolic located disorder of the subcutaneous tissue that provokes an alteration in the physical form, where many structures are alterated in the dermis, in the microcirculation and within the adipocytes. This phenomenon is associated to morphological, histochemical and biochemical modifications in the skin, culminating in the alterations that lead to the aesthetic discomfort and to the clinical appearance of the cellulitis. These alterations are consequence, in parts, from the lipid accumulation into the adypocites, crucial cells in the lypolisis-lipogenesis balance, and it is considerate as a glandular functional unity able to promote a fine-tune interaction with the central nervous system. Recent studies indicate the search for active substances with the ability of promote the dermo-hypodermic homeostasis through lipolytic action, allied to the stimulus of the production of growth factors, mainly TGF-? and GM-CSF, proteins of extracellular matrix, such as collagen, elastin and glycosaminoglycans, as well as substances ables to regulate the adipocyte metabolism. According to the clinical and aesthetic complexity of the cellulitis, as well as the biochemical alterations in the dermis and hypodermis, in this work we evatuate the effects of green coffee seed oil (Coffea arabica L.) and canola phytoesterols (Brassica campestris L.) (F), whose association is the product Slimbuster L (SBL). In this way, we evaluate in this study the effects of these compounds through in vitro, ex-vivo and clinical assessment, using methodologies and experimental models that show the global vision of the process of cellulites. The results demonstrate that SBL was able to stimulate significantly the lipolysis, the synthesis of leptin in human adipocyte cell culture, the production of GM-CSF, TGF-?, collagen, elastin and GAGs in human fibroblast cell culture, the contraction of fibroblastos in collagen gel matrix, as well as promoting the improvement of skin general histologic aspect. The separated fractions (OC and F) also demonstrated important and different effects, being this more pronounced for OC and when both (OC e F) are associated (SBL). The clinical results demonstrate that Slimbuster L was well appreciated by the volunteers for the items "facility of application", "more smooth skin" and "shear it more me" reduction of cellulite" and "reduction of fat accumulation", specially after 60 days use of a body lotion containing 3.0% (w/w) of SBL. The results of the instrumental assessment obtained demonstrate that SBL was able to reduce significantly the measures in the region of the thigh (superior, medium and inferior), being this centrimetric reduction observed in approximately 30% of the panel at D30 and in 50% of the panel at D60. The other evaluated areas - abdome, legs and hips - did not present statistical significance, however they must be taken into account since they presented strong tendency after 60 days of application of the body lotion, indicating a possible improvement with the time of use. The adipometric analysis of the volunteers demonstrated a strong tendency of accumulated fat reduction in the areas of abdomen, supra-iliac, supra-spinal and proximal thigh. The thickness of hypodermis measured by ultrasonography (ecography) showed a reduction superior to 2% in the areas of the thigh and abdomen in approximately 70% of the panel in the all experimental evaluated times (D30 and D60). In according to the results presented in this work, we can conclude that the product Slimbuster L can be considered a safe and efficient tool in the prevention and topical treatment of the located fat and cellulite / Doutorado / Farmacologia / Doutor em Farmacologia
62

Efeitos da suplementação de manteiga e margarinas no metabolismo lipídico e inflamação de portadores de síndrome metabólica que mantiveram seus hábitos usuais de vida / Effects of butter and margarines supplementation in the lipid metabolism and inflammation of metabolic syndrome individuals in free living state

Ana Carolina Moron Gagliardi Miguel 09 February 2010 (has links)
Introdução: O consumo de manteigas e margarinas faz parte do hábito alimentar da população e é uma forma eficaz de suplementação de ácidos graxos. No entanto, até o momento se desconhece os efeitos de ácidos graxos saturados, trans, monoinsaturados, poliinsaturados e de fitosteróis no perfil lipídico, inflamatório, de marcadores de disfunção endotelial e no metabolismo da HDL em indivíduos com síndrome metabólica (SM). Objetivo: Examinar os efeitos do consumo diário de manteiga, margarina com ácido graxo trans, margarina com fitosterol e margarina sem ácido graxo trans, em quantidades recomendadas por diretrizes, sobre: 1) o perfil lipídico, apolipoproteínas (Apo), marcadores inflamatórios e de disfunção endotelial e transferência de lipídeos para HDL, em indivíduos com SM, sem alterar seus hábitos usuais de vida, 2) a associação desses parâmetros com a composição nutricional das dietas dos indivíduos estudados. Métodos: Este estudo foi randomizado, cego, onde 100 indivíduos receberam porções diárias isocalóricas de manteiga ou margarina com ácido graxo trans ou margarina com fitosterol ou margarina sem ácido graxo trans em adição às suas dietas usuais, por 5 semanas. Foram determinados: perfil lipídico, Apos, marcadores inflamatórios e de disfunção endotelial, LDL pequenas e densas e transferências de lipídeos para a HDL. Diferenças entre os grupos foram avaliados por ANOVA. Resultados: A amostra final foi composta por 66 indivíduos (63,6% mulheres, idade média 47,6 anos). Houve redução de -10,3% na Apo B (p=0,043) e de -15,2% na razão Apo B/Apo A-I (p=0,034) após consumo de margarina com fitosterol. Não foram verificadas diferenças significativas nos lípides após consumo de manteiga, margarina com trans ou margarina sem trans. Transferências de fosfolípides foram reduzidas no grupo margarina com fitosterol (-4,7% vs. margarina com trans p=0,037); no grupo margarina sem trans foram reduzidas as transferências de: colesterol éster (-27% vs. manteiga e margarina com trans p=0,002), triglicérides (-43,3% vs. outros grupos p<0,001) e colesterol livre (-16,4%, vs. margarina com trans e margarina com fitosterol p=0,006). Não foram verificadas alterações significantes nos marcadores inflamatórios e de disfunção endotelial entre os grupos. Associações foram observadas entre os marcadores inflamatórios e de disfunção endotelial e consumo de lipídeos totais, ácidos graxos saturados, mono e poliinsaturados, colesterol, além de consumo energético e de carboidratos. As transferências de lipídeos para HDL associaram-se inversamente com o consumo de fibra alimentar. Conclusão: Nossos resultados indicam que o consumo de manteiga, margarina com ácido graxo trans e margarina sem ácido graxo trans, nas quantidades estudadas, por indivíduos com síndrome metabólica que não alteraram seus hábitos usuais de vida, não modificam o perfil lipídico ou marcadores inflamatórios e de disfunção endotelial. O consumo de margarina com fitosterol e margarina sem trans nas quantidades recomendadas reduziram respectivamente a concentração de Apo B e a habilidade da HDL de receber lípides. Os marcadores inflamatórios e de disfunção endotelial associaram-se com o consumo de gorduras e carboidratos, sugerindo que dietas ricas em gorduras e calorias podem modular a resposta inflamatória em indivíduos com SM. / Introduction: The consumption of butter and margarines are part of population dietary habits and is an effective form of fatty acid supplementation. However, the effects of saturated, trans, monounsaturated and polyunsaturated fatty acids and of plant sterol supplementation in the lipid profile, inflammation and endothelial dysfunction markers, and in the metabolism of HDL in individuals with the metabolic syndrome (MS) are unknown. Objective: Examine the effects of daily servings of butter, trans fat margarine, no trans fat margarine, and plant sterol margarine, within guideline recommended amounts, on: 1) plasma lipids, apolipoproteins (Apo), biomarkers of inflammation and endothelial dysfunction and on the lipid transfer of radioactive lipids to HDL particles in free-living subjects with the MS, 2) to analyze the association of these parameters with the nutritional composition of the individuals\' diets. Methods: This was a randomized, single-blind study where 100 MS subjects received isocaloric servings of butter, trans fat margarine, no-trans fat margarine or plant sterol margarine in addition to their usual diets for 5 weeks. The main outcome measures were plasma lipids, Apo, inflammatory and endothelial dysfunction markers, small dense LDL cholesterol concentration and in vitro radioactive lipid transfer from cholesterol-rich emulsions to HDL. Difference among groups was evaluated by ANOVA. Results: Sixty-six subjects completed the study (63.6% women, mean age 47.6 years). There was a significant reduction in Apo B (-10.3 %, p=0.043) and in the Apo B/A-1 ratio (-15.2%, p=0.034) with plant sterol margarine. No changes in plasma lipids were noticed with butter, trans fat margarine and no-trans fat margarine. Transfer rates of lipids to HDL were reduced in the plant sterol margarine group: phospholipids -4.7% (p=0.037 vs. trans fat margarine) and in the no-trans fat margarine group: triglycerides -43.3%, (P<0.001 vs. other groups), cholesterol ester -27% (p=0.002 vs. butter and trans fat margarine) and free cholesterol -16.4% (p=0.006 vs. trans fat and plant sterol margarine). No significant effects were noted on inflammatory and endothelial dysfunction markers concentrations among the groups. An association was observed among the inflammatory markers and of endothelial dysfunction and the consumption of total lipids, saturated, monounsaturated and polyunsaturated fatty acids, cholesterol, energy consumption and carbohydrates. The transfer rates of lipids to HDL were inversely associated with the consumption of dietary fiber. Conclusions: In free living subjects with the MS the consumption of butter, trans fat margarine and no-trans fat margarine, within recommended amounts did not modify the lipid profile or markers of inflammation and endothelial dysfunction. The consumption of plant sterol and no-trans fat margarines reduced respectively Apo B concentrations and the ability of HDL to accept lipids. The inflammatory and endothelial dysfunction markers were positively associated with the consumption of fats and carbohydrates suggesting that diets rich in fats and calories can modulate inflammation in subjects with the MS.
63

Avaliação dos efeitos do ácido linoléico conjugado (CLA), dos fitosteróis e de sua combinação na regulação de parâmetros bioquímicos, oxidativos e na composição corporal de ratos Sprague Dawley / Evaluation of the effects of conjugated linoleic acid (CLA), phytosterols and their combination in the regulation of biochemical and oxidative parameters and body composition in Sprague Dawley rats

Marineli, Rafaela da Silva, 1986- 03 February 2012 (has links)
Orientador: Mario Roberto Marostica Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T15:52:41Z (GMT). No. of bitstreams: 1 Marineli_RafaeladaSilva_M.pdf: 1312364 bytes, checksum: 642784e4925126072a876363cda8324f (MD5) Previous issue date: 2012 / Resumo: Têm-se atribuído inúmeros efeitos biológicos ao ácido linoléico conjugado (CLA) e aos fitosteróis. O CLA vem sendo estudado principalmente por sua ação anticarcinogênica, imunomoduladora, reguladora do balanço energético, pela alteração do perfil lipídico e da composição corporal, influência sobre o processo de resistência à insulina e aumento da oxidação lipídica. Os fitosteróis levam a redução dos níveis de colesterol sérico e, consequentemente, a prevenção de doenças cardiovasculares, além de outros efeitos benéficos reportados recentemente, como atividade antidiabetogênica e antioxidante. É possível que a interação entre CLA e fitosteróis melhore ou potencialize os seus efeitos biológicos isolados. O objetivo deste trabalho foi avaliar os efeitos causados pela associação da suplementação de CLA e de fitosteróis no perfil lipídico, hormonal e oxidativo, na sensibilidade à insulina e na composição corporal in vivo. Foi realizado um ensaio biológico com 40 ratos machos Sprague Dawley, saudáveis, em crescimento divididos em 5 grupos (n=8) e alimentados por 9 semanas com dieta normolipídica (AIN-93G) suplementada com 2% dos compostos lipídicos de interesse: grupo S com óleo de soja (padrão), grupo LA com óleo de cártamo (controle), grupo CLA com CLA TonalinÒ, grupo P com fitosteróis Vegapure 95FFÒ e grupo CLA+P com uma mistura de CLA e fitosteróis. Foram determinados e avaliados: ingestão alimentar, ganho de peso, peso dos órgãos, composição corporal, perfil lipídico e hormonal, teste de tolerância à glicose e à insulina, conteúdo de lipídios hepáticos e fecais, enzimas antioxidantes e produtos primários e secundários da autoxidação lipídica. A associação entre CLA e fitosteróis não alterou a ingestão de dieta, ganho de peso, composição corporal, peso dos rins, coração e fígado, mas reduziu o peso do tecido adiposo epididimal (-42%), sem alteração no conteúdo de lipídios hepáticos e perfil lipídico sérico; aumentou a concentração de insulina sérica sem comprometer a sensibilidade à insulina, já que os testes de tolerância à glicose e à insulina e os índices de HOMA-IR não diferiram entre os grupos. Além disso, o consumo isolado da mistura dos isômeros do CLA diminuiu o consumo de dieta, sem alteração do ganho de peso dos animais, reduziu os níveis de leptina sérica e aumentou o peso do fígado dos animais sem alterar o conteúdo de lipídios hepáticos. O consumo isolado de fitosteróis reduziu a glicose sanguínea, melhorando o índice de HOMA-BCF, e aumentou a excreção de lipídios fecais em 6 vezes, com ou sem a adição de CLA. Quanto ao perfil oxidativo, o grupo CLA+P não apresentou alteração nos valores plasmáticos de MDA e GSH, na atividade das enzimas SOD, GRd e GPx, mas restaurou os níveis de isoprostana e a atividade de catalase aos valores basais, as quais estiveram aumentadas com a suplementação de CLA. A suplementação com CLA+P também reduziu os produtos primários e secundários da peroxidação lipídica no fígado. A suplementação isolada de fitosteróis e de CLA também foi capaz de reduzir a peroxidação lipídica no fígado dos animais e os valores plasmáticos de MDA. Tendo em vista os resultados encontrados, pôde-se concluir que a associação entre a suplementação de CLA e fitosteróis não apresentou efeito sobre a composição corporal, perfil hormonal e lipídico, mas atuou positivamente na redução do tecido adiposo, sem comprometer a sensibilidade à insulina e induzir a hepatomegalia ou esteatose hepática. Além disso, o efeito sinérgico entre esses compostos melhorou o perfil oxidativo e reduziu a peroxidação lipídica nos animais. Porém, os mecanismos responsáveis por tais alterações não foram elucidados, sendo necessárias outras investigações / Abstract: Several biological effects have been assigned to the conjugated linoleic acid (CLA) and phytosterols. CLA has been studied mainly by anticarcinogenic actions, immunomodulatory, regulation of energy balance, modulation of circulating lipids and body composition, influence on the process of insulin resistance and increase in lipid oxidation. Phytosterols provide a reduction in serum cholesterol levels and prevent cardiovascular disease, and other biological effects reported recently, as antidiabetic and antioxidant activity. It is possible that the interaction between CLA and phytosterols improves or potentiate their isolated effects. The aim of this work was to evaluate the effects of dietary CLA associated with phytosterols on lipid, hormonal and oxidative profile, insulin sensitivity and body composition in vivo. A biological assay was conducted with 40 male healthy Sprague Dawley rats divided into 5 groups (n = 8) and fed for 9 weeks with a standard lipid diet (AIN-93G) supplemented with 2% of lipid compounds of interest: group S with soybean oil (standard), group LA with safflower oil (control), group CLA with CLA TonalinÒ, group P with phytosterols Vegarupe 95FFÒ, and group CLA+P with a mixture of CLA and phytosterols. Food intake, weight gain, organs weight, body composition, lipid and hormonal profile, glucose tolerance test and insulin tolerance test, hepatic and fecal lipid content, antioxidant enzymes, primary and secondary lipid autoxidation products were determined. The association between CLA and phytosterols did not alter food intake, weight gain, body composition, kidneys, heart and liver weight, but reduced epididymal adipose tissue weight (-42%), without change in hepatic lipids content and lipid profile, increased serum insulin concentration, without impairment of insulin sensitivity, since the glucose tolerance test, insulin tolerance test and HOMA-IR index did not differ among the groups. In addition, the isolated consumption of mixture CLA isomers reduced food intake, without alter the weight gain of animals, reduced serum leptin and increased animals liver weight without change the hepatic lipid content. And the isolated consumption of phytosterols reduced blood glucose, improving the HOMA-BCF index, and increased lipid fecal excretion by 6 times, with or without the addition of CLA. For the oxidative profile, CLA+P group showed no change in plasma MDA and GSH levels, SOD, GPx and GRd activity, but restored the levels of isoprostane and catalase activity to baseline, which were increased with CLA supplementation. Supplementation with CLA+P also reduced the primary and secondary products of lipid peroxidation in the liver. Supplementation of isolated phytosterols and CLA was also able to reduce lipid peroxidation in liver and plasma levels of MDA. We concluded that the association between phytosterols and CLA supplementation had no effect on body composition, hormonal and lipid profile, but acted positively on the reduction of adipose tissue without impairment of insulin sensitivity and hepatic steatosis or hepatomegaly. In addition, the synergistic effect between these compounds improved the oxidative profile and reduced lipid peroxidation in animals. However, the mechanisms responsible for these changes were not elucidated, so further investigations are necessary / Mestrado / Nutrição Experimental e Aplicada à Tecnologia de Alimentos / Mestre em Alimentos e Nutrição
64

Atividade antibacteriana de extrato de butiá (Butia odorata) contra bactérias patogênicas / Antibacterial activity of butiá (Butia odorata) extracts against pathogenic bacteria

Maia, Darla Silveira Volcan 01 February 2017 (has links)
Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2017-03-14T17:41:15Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Darla Silveira Volcan Maia.pdf: 1194381 bytes, checksum: b604e15daa48092534ea10a3647416c8 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-17T22:15:15Z (GMT) No. of bitstreams: 2 Dissertação Darla Silveira Volcan Maia.pdf: 1194381 bytes, checksum: b604e15daa48092534ea10a3647416c8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-17T22:15:15Z (GMT). No. of bitstreams: 2 Dissertação Darla Silveira Volcan Maia.pdf: 1194381 bytes, checksum: b604e15daa48092534ea10a3647416c8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-01 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / A demanda por alimentos livres de conservantes químicos sintéticos tem aumentado. Nos últimos anos, vários estudos foram realizados a fim de se obter compostos antimicrobianos naturais. Alguns estudos foram realizados com frutas nativas do Brasil, no entanto, não existem estudos avaliando o potencial antibacteriano do butiá. O objetivo deste estudo foi prospectar a atividade antibacteriana de extratos de butiá (Butia odorata) com diferentes polaridades e caracterizar quimicamente o extracto com a melhor atividade. Um extrato hexânico e um metanólico de butiá foram avaliados quanto à sua atividade antibacteriana contra três bactérias Gram-positivas (Listeria monocytogenes, Staphylococcus aureus e Bacillus cereus) e três bactérias Gram-negativas (Salmonella Typhimurium, Escherichia coli O157:H7 e Pseudomonas aeruginosa), pelo método de difusão em ágar, Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM). Ambos extratos apresentaram atividade antibacteriana, entretanto, o extrato hexânico (EHB) apresentou desempenho superior, portanto realizou-se a caracterização química por CG-MS deste extrato. Interessantemente, o EHB apresentou maior atividade contra bactérias Gram-negativas, sendo E. coli O157:H7, a mais sensível (CBM 5 µL.mL-1 ). Entre as bactérias Gram-positivas, S. aureus (CBM 20 μL.mL-1 ) foi a mais sensível. Os fitoesteróis representaram 51% do EHB, sendo gama-sitosterol o composto predominante, constituindo 22% do extrato. / Demand for synthetic chemical preservative free foods has increased. In recent years several studies have been conducted in order to obtain natural antimicrobial compounds. Some studies were performed with native fruit from Brazil, however there are no studies evaluating the potential antibacterial of jelly palm fruits (butiá). The objective of the study was exploring the antibacterial activity of butiá (Butia odorata) extracts with different polarities and chemically characterize the extract with the best activity. A hexane and a methanol extract of butiá were evaluated for their antibacterial activity against three Grampositive (Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus) and three Gram-negative bacteria (Salmonella Typhimurium, Escherichia coli O157:H7, and Pseudomonas aeruginosa) by the agar diffusion method, Minimal Inhibitory Concentration (MIC), Minimal Bactericidal Concentration (MBC). Both extracts showed antibacterial activity, however of hexane extract (BHE) showed superior performance, therefore the chemical characterization by CG-MS for this extract. Interestingly, the BHE higher activity against Gram-negative bacteria, and E. coli O157:H7 was the most sensitive (MBC 5 μL.mL-1 ). Of the Gram-positive bacteria, S. aureus (MBC 20 μL.mL-1 ) was the most sensitive. Phytosterols represented 51% of the BHE and gamma-sitosterol was the predominant compound constituting 22% of the extract.
65

Evaluation of a functional oil composed of medium chain triacylglycerols, phytosterols and n-3 fatty acids on the cardiovascular risk profile of overweight women

Bourque, Christine. January 2002 (has links)
No description available.
66

Composition chimique et propriétés anti-inflammatoires de l'huile de pulpe d'awara (Astrocaryum vulgare M.) / Chemical composition and anti-inflammatory properties of awara pulp oil (Astrocaryum vulgare M.)

Bony, Emilie 13 December 2010 (has links)
L'awara (Astrocaryum vulgare M.) est le fruit d'un palmier utilisé principalement au niveau alimentaire pour sa pulpe riche en huile. L'objectif de ce travail a été de caractériser chimiquement l'huile de pulpe d'awara et d'évaluer ses propriétés anti‑inflammatoires dans différents modèles expérimentaux. L'huile de pulpe, dont les acides gras principaux sont l'acide oléique et palmitique, a montré une forte teneur en caroténoïdes. Les microconstituants identifés sont principalement représentés par le β‑carotène (caroténoïdes), le β‑sitostérol, l'arundoin (phytostérols) et l'α‑tocopérol. L'huile de pulpe a montré des effets anti‑inflammatoires dans un modèle in vivo de choc endotoxique par inhibition de la production de cytokines pro‑inflammatoires (tumor necrosis factor α (TNFα), interleukin (IL)‑6) et augmentation de la production d'une cytokine anti‑inflammatoire (IL‑10). Ces effets anti‑inflammatoires ont été confirmés dans un modèle in vivo d'inflammation bronchique. L'huile de pulpe a diminué l'afflux de cellules inflammatoires au niveau pulmonaire, principalement d'éosinophiles et de lymphocytes. La fraction insaponifiable a, par la suite, montré des effets inhibiteurs sur la production de différents médiateurs inflammatoires (oxyde nitrique, prostaglandine E2, TNFα, IL‑6, IL‑10) ainsi que sur l'expression d'enzymes induites lors de l'inflammation (iNOS et COX‑2) dans un modèle in vitro de macrophages activés. La fraction insaponifiable a également montré un effet inhibiteur sur la production de cytokines (TNFα, d'IL‑6 et d'IL‑10) dans le modèle in vivo de choc endotoxique. Ces résultats confirment l'implication des microconstituants de l'huile de pulpe d'awara dans ses effets antioxydants et anti‑inflammatoires et suggèrent un rôle préventif et/ou thérapeutique de l'huile de pulpe d'awara et de sa fraction insaponifiable dans les pathologies associées à l'inflammation. / Awara (Astrocaryum vulgare M.) is a palm fruit mainly used for nutritional purpose because of its oily pulp. The aim of this study was to characterize awara pulp oil and evaluate its anti‑inflammatory properties in different experimental models. The pulp oil, whose major fatty acids are oleic and palmitic acid, showed a high content of carotenoids. The minor compounds identified are mainly represented by β‑carotene (carotenoids), β‑sitosterol, arundoin (phytosterols) and α‑tocopérol. The pulp oil showed anti‑inflammatory effects in an in vivo model of endotoxic shock by inhibiting the production of proinflammatory cytokines (tumor necrosis factor α (TNFα), interleukin (IL)‑6) and increasing the production of an anti‑inflammatory cytokine (IL‑10). These anti‑inflammatory effects have been confirmed in an in vivo model of airway inflammation. The pulp oil has reduced the influx of inflammatory cells in the lungs, mainly of eosinophils and lymphocytes. The unsaponifiable fraction has subsequently shown inhibitory effects on the production of various inflammatory mediators (nitric oxide, prostaglandin E2, TNFα, IL‑6, IL‑10) and on the expression of enzymes induced during inflammation (iNOS and COX‑2) in an in vitro model of activated macrophages. The unsaponifiable fraction also showed an inhibitory effect on cytokine production (TNFα, IL‑6 and IL‑10) in endotoxic shock model. These results confirm the role of micronutrients of awara pulp oil in its anti‑inflammatory properties and suggest a preventive and/or therapeutic role of awara pulp oil and its unsaponifiable fraction in inflammation‑related diseases.
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Characterization of chemical markers for the discrimination of East Asian handmade papers using pyrolysis, gas chromatography and mass spectrometry / Caractérisation de marqueurs chimiques pour l'identification des papiers traditionnels asiatiques en utilisant la pyrolyse, la chromatographie gazeuse et la spectrométrie de masse

Han, Ung Bin 11 July 2018 (has links)
Cette thèse a été conduite afin d’explorer le potentiel d’une nouvelle méthodologie utilisant la pyrolyse, la chromatographie gazeuse et la spectrométrie de masse pour la caractérisation et l’identification des fibres papetières utilisées dans la fabrication des papiers asiatiques traditionnels à partir de la caractérisation des métabolites de ces fibres. Cette méthodologie utilise un processus d’échantillonnage facilité nécessitant une très petite quantité d’échantillons (de l’ordre de quelques dizaines de µg). Après la pyrolyse des échantillons de papiers et la séparation chromatographique des composés formés, des distributions caractéristiques pour les métabolites des fibres papetières (considérant leur présence et leur intensité) ont été observées dans une région définie comme région d’intérêt dans les chromatogrammes: ces distributions se sont révélées spécifiques pour la caractérisation des papiers fabriqués à partir de différents types de fibres et ont été utilisées pour distinguer l’origine des différentes fibres papetières couramment utilisées dans la fabrication de papiers asiatiques traditionnels. Premièrement, les problèmes rencontrés dans l’étude des papiers faits à la main ont été présentés, comme l’origine de la fabrication du papier, l’incohérence de certains résultats dans l’identification des fibres (reportés dans différentes études scientifiques), les limites de la microscopie pour l’identification des fibres papetières d’origines botaniques similaires et les risques d’imprécision dans le référencement des échantillons. Tous ces problèmes montrent la nécessité d’explorer de nouvelles méthodes pour (1) améliorer la fiabilité de l’identification des fibres papetières des papiers asiatiques traditionnels, (2) valider et confirmer les résultats obtenus par l’analyse microscopique. À cette fin, dans un premier temps, des papiers asiatiques de référence ont été étudiés. Les résultats expérimentaux ont montré que les différentes fibres papetières utilisées pour la fabrication des papiers étudiés montraient des différences dans les distributions de leurs marqueurs spécifiques : par exemple, les fibres d’origine de la famille Moraceae montrent une distribution caractéristiques de composés triterpèniques alors que les fibres d’origine de la famille Thymelaeaceae montrent une distribution caractéristiques de composés de type stigmastanes. De leur côté, les fibres des plantes appartenant au groupe Ma montrent peu de métabolites caractéristiques. Les différences observées dans la distribution de ces métabolites ont été attestées par la comparaison entre distributions obtenues à partir des fibres végétales et celles des papiers faits à la main attestant de l’origine commune de ces métabolites issus des tissus végétaux d’origine. Ainsi, la méthodologie étudiée se révèle prometteuse en tant que méthode de chimiotaxonomie pour l’identification des fibres inconnues de papiers faits à la main. Avec les exemples d'applications fournies au cours du travail expérimental, le couplage de la pyrolyse, de la chromatographie en phase gazeuse et de la spectrométrie de masse (avec l’utilisation de la Py-GC/MS et de la Py-GCxGC/MS) a montré sa capacité à distinguer les fibres d'une même famille (qui peuvent présenter des caractéristiques similaires en microscopie) et peut ainsi constituer une méthode efficace d'identification des fibres et de validation des résultats d'identification obtenus par l'observation microscopique. Dans la présente thèse, les caractéristiques de la chromatographie gazeuse intégralement bidimensionnelle GCxGC, ses avantages pour les applications dans le domaine du patrimoine culturel et son apport potentiel pour le traitement des données 1D ont été discutées (...) / This study was conducted to explore a new methodology for handmade fiber characterizationand identification using pyrolysis, gas chromatography and mass spectrometry. It employseasy sampling process with minor quantity of samples required. After pyrolysis of handmadepapers, a featured metabolites distribution patterns (presence plus intensity) eluting in the defined region of interest (ROI) was observed to be characteristic for handmade papers of different material origins. The method utilizes these metabolites distribution patterns as markers to discriminate different fiber origins. Firstly, the problems encountered in the investigation of handmade papers were introduced such as the origin of papermaking, the inconsistency in the fiber identification results sometimes gained by different scholars, the limits of microscopy in identifying fibers from similar species and the likely imprecision of the reference sample labeling. All these problems showed the necessity to explore a new method in order to (i) make precise fiber identification of handmade papers and (ii) to validate or confirm the identification results obtained by microscopy. Then, modern reference handmade papers were firstly studied. The result revealed that different plant fibers used for papermaking have different marker distributions in the ROI, forinstance, the Moraceae family with a featured distribution of terpene compounds and theThymelaeaceae family with a featured distribution of stigmasta compounds. The fibers fromthe ma group usually revealed few compounds in the ROI. This metabolites difference in theROI was attested from the plant tissues with their similar distribution in handmade papers and plant raw fibers. Thus, the chosen methodology offers promise as a method of chemotaxonomy for unknown handmade paper fiber identification. With the examples ofapplications provided during the experimental work, the coupling of pyrolysis, gaschromatography and mass spectrometry (through the use of Py-GC/MS and Py-GCxGC/MS)showed its ability to distinguish fibers from the same plant family (that may present similar microscopic features) and thus, can constitutes an effective method for fiber identification as well as to validate the identification results of the microscopic observation. In the present thesis, the features of GCxGC and the benefits for cultural heritage applications and its help for the ID data treatment were discussed. The tested Py-GCxGC/MS methodology has been for the first time proposed in the cultural heritage field and it harbors the potential to promote the research in this domain, enhancing our capacity to handle small quantities of complex samples while providing an exhaustive response on its composition.
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Etude de la régulation du VDAC des mitochondries de Phaseolus coccineus par les lipides membranaires / Study of the regulation of Phaseolus coccineus mitochondrial VDAC by membrane lipids.

Mlayeh, Lamia 11 September 2013 (has links)
Chez les végétaux, peu de canaux ioniques sont identifiés moléculairement. Nos travaux, par l’apport de preuves fonctionnelles, mettent en évidence les propriétés électrophysiologiques d’une protéine de la membrane mitochondriale externe (MOM) de Phaseolus coccineus, VDAC32. Nous montrons que cette protéine forme un canal partageant plusieurs caractéristiques électrophysiologiques typiques des canaux anioniques voltages dépendants (VDACs) (cinétique d'ouverture et de fermeture, sensibilité au voltage, conductance relativement grande, courbe de voltage dépendance en forme de cloche). <p>Nous avons constaté que la concentration saline avait un effet sur la voltage-dépendance du canal. En effet, le VDAC devient insensible à la différence de potentiel appliquée lorsqu'il est reconstitué dans des concentrations physiologiques en sel. Nombreuses sont les expériences réalisées dans des conditions non physiologiques (1 M KCl), mais nous montrons dans ce travail que le canal ne se comporte pas de la même manière en conditions physiologiques (0,1 M KCl).<p>La première partie de notre travail a été consacrée à l’étude de l’effet du cholestérol et deux phytostérols les plus abondants (sitostérol et stigmastérol) sur la voltage-dépendance du VDAC. Dans ce chapitre, nous avons montré l’effet des stérols sur la fonction des canaux ioniques au niveau moléculaire. Le rôle des stérols sur la sélectivité et la voltage-dépendance du VDAC a été mis en évidence. L’étude des phytostérols a permis de comprendre comment les propriétés du VDAC peuvent être modulées avec le type de stérol et son abondance dans la membrane. De même, la réversibilité de l’effet des phytostérols sur le VDAC en présence de la Méthyle-β-cyclodextrine a été prouvée. La conductance unitaire n’était pas affectée par l’addition des stérols.<p>Le deuxième chapitre de cette thèse a été consacré à l’étude des deux principaux phospholipides membranaires ;la phosphatidylcholine (PC) et phosphatidyl-éthalamine (PE). Il a été montré qu’à des concentrations salines similaires à celles trouvées in vivo, la voltage-dépendance du VDAC est inhibée en présence de membrane formée de PC mais pas en présence de membrane formée de PE et/ou PE méthylé une fois et deux fois. De même, la voltage-dépendance est restaurée suite à l’ajout de 2% de phytostérol ou de 2% de PE ou lorsque le degré de méthylation de la choline diminue. L’effet des stérols sur la voltage-dépendance est réversible. Nous avons montré que la sélectivité aux anions augment lorsque le degré de méthylation de la choline diminue tandis que la conductance unitaire du canal est invariable.<p>Nos résultats indiquent que l’interaction lipide-protéine est essentielle pour la régulation de l’activité du canal VDAC. La nature de la tête polaire des lipides est déterminante pour cette régulation ce qui suggère qu’elle s’effectue au niveau de l’interface membrane-solution. <p>La suite de nos travaux nous a conduit à l’étude de l’effet du cation monovalent, divalent et trivalent sur le VDAC. Nous avons montré que la voltage-dépendance est perdue dans des concentrations faibles en KCl (100 mM) et que cette dernière est restaurée en présence de 800 mmolale en KCl ou 100 mM de calcium ou 30 mM de lanthane. Ces résultats suggèrent que la restauration de la voltage-dépendance à des faibles concentrations en sel (100 mmolale) impliquerait un effet électrostatique/In plants, only some ion channels are identified molecularly. By providing functional evidence, our work highlights electrophysiological properties of the outer mitochondrial membrane (MOM) protein of Phaseolus coccineus, VDAC32. We show that this protein forms a channel sharing several typical electrophysiological characteristics of voltages dependent anion channels (VDACs) (gating kinetics, voltage sensitivity, relatively large conductance, voltage dependence curve bell-shaped).<p>We found that the salt concentration had an effect on the voltage-dependence of channel. Indeed, VDAC becomes insensitive to the applied potential difference when it was reconstituted in physiological salt concentrations. The greater part of the experiments were performed under non-physiological conditions (1 M KCl), but we show in our work that the channel does not have the same behavior under physiological conditions (0.1 M KCl).<p>The first part of our work has been devoted to the study of the effect of cholesterol and the two most abundant phytosterols (sitosterol and stigmasterol) on the VDAC voltage dependence. In this chapter, we have shown the effect of sterols on ion channel function at the molecular level. The role of sterols on the selectivity and the voltage-dependence of VDAC was highlighted. The study of phytosterols helped us to understand how the properties of VDAC can be modulated with the type of sterol and its abundance in the membrane. Similarly, the reversibility of the effect of phytosterols on the VDAC in the presence of Methyl-β-cyclodextrin has been proven. The unit conductance was not affected by the addition of sterols.<p>The second chapter of this thesis was devoted to the study of the two major membrane phospholipids, phosphatidylcholine (PC) and phosphatidylethalamine (PE). It has been shown that in similar salt concentrations to those found in vivo, the VDAC voltage-dependence is inhibited in the presence of membrane formed by PC but not in the presence of membrane formed by PE and/or PE methylated once and two times. Similarly, the voltage-dependence is recovered following the addition of 2% of phytosterol or 2% of PE or when the degree of methylation of choline decreases. The effect of sterols on the voltage-dependence is reversible. We have shown that the anion selectivity increases when the degree of methylation of choline decreases while the unitary conductance of the channel is invariable.<p>Our results indicate that lipid-protein interaction is essential for the regulation of the activity of VDAC channel. The nature of the lipids polar head is crucial for this regulation suggesting that it occurs at the membrane-solution interface.<p>The rest of our work has led us to study the effect of monovalent, divalent and trivalent cation on VDAC. We have shown that the voltage-dependence is lost in low concentrations of KCl (100 mM) and it is restored in the presence of 800 mmolale of KCl or 100 mM of calcium or 30 mM of lanthanum. These results suggest that the restoration of the voltage-dependence at low salt concentrations (100 mmolale) involve an electrostatic effect.<p> / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished
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A Euterpe oleracea (açaí) modifica o metabolismo de esteróis e atenua a aterosclerose induzida experimentalmente / Euterpe oleracea (açai) modifies sterol metabolism and attenuates experimentally-induced atherosclerosis

Feio, Claudine Maria Alves [UNIFESP] 26 October 2011 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:49:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-10-26. Added 1 bitstream(s) on 2015-08-11T03:26:12Z : No. of bitstreams: 1 Publico-12819.pdf: 1531638 bytes, checksum: 73bb6d6fd7336127fb68327a46db002f (MD5) / Introducao: Euterpe oleracea (acai) e uma fruta da regiao amazonica, cuja composicao quimica pode ser benefica para individuos com aterosclerose. Nos hipotetizamos que o consumo de Euterpe oleracea poderia reduzir o desenvolvimento da aterosclerose por uma reducao na absorcao e sintese de colesterol. Metodos: Coelhos machos Nova Zelandia foram alimentados com uma dieta enriquecida em colesterol (0.5%) por 12 semanas, quando foram aleatoriamente distribuidos para tratamento com Euterpe oleracea ou agua alem de dieta enriquecida em colesterol (0,05%) por 12 semanas adicionais. Fitosterois plasmaticos e desmosterol foram determinados por cromatografia liquida de alto desempenho e espectrometria de massa. As lesoes ateroscleroticas foram estimadas por planimetria computadorizada. Resultados: Ao sacrificio, os animais tratados com Euterpe oleracea tiveram menores niveis de colesterol total (p=0.03) e de colesterol nao-HDL (p=0.03) em comparacao aos controles. Estes animais tiveram menores areas de aterosclerose em suas aortas ((p=0.001) e menor relacao intima/media (p=0.002) em comparacao aos controles. Ao final do estudo, os valores plasmaticos de campesterol, ƒÀ-sitosterol, e desmosterol nao diferiram entre os grupos. Entretanto, os animais tratados com Euterpe oleracea mostraram menores valores para as relacoes desmosterol/campesterol (p=0.026) e desmosterol/ƒÀ-sitosterol (p=0.006) em comparacao aos controles. Conclusoes: Consumo do extrato de Euterpe oleracea marcadamente melhora o perfil lipidico e atenua a aterosclerose. Estes efeitos foram em parte relacionados a um melhor balanco entre sintese e absorcao de esterois. / Background: Euterpe oleracea (acai) is a fruit from the Amazon region, whose chemical composition may be beneficial for individuals with atherosclerosis. We hypothesized that consumption of Euterpe oleracea would reduce therosclerosis development by a decrease in cholesterol absorption and synthesis. Methods: Male New Zealand rabbits were fed a cholesterol-enriched diet (0.5%) for 12 weeks, when they were randomized to receive Euterpe oleracea extract or water plus a 0.05% cholesterol-enriched diet for additional 12 weeks. Plasma phytosterols and desmosterol were determined by ultra performance liquid chromatography and mass spectrometry. Atherosclerotic lesions were estimated by computerized planimetry. Results: At sacrifice, animals treated with Euterpe oleracea had lower levels of total cholesterol (p=0.03) and non-HDL-cholesterol (p=0.03) as compared to controls. These animals had smaller atherosclerotic plaque area in their aortas (p=0.001) and a smaller intima/media ratio (p=0.002) in comparison with controls. At the end of the study, campesterol, ƒÀ-sitosterol, and desmosterol plasma levels did not differ between groups. However, animals treated with Euterpe oleracea showed lower values for the desmosterol/campesterol (p=0.026) and desmosterol/ƒÀ-sitosterol (p=0.006) ratios as compared to controls. Conclusion: Consumption of Euterpe oleracea extract markedly improved the lipid profile and attenuated atherosclerosis. These effects were related in part to a better balance in the synthesis and absorption of sterols. / TEDE / BV UNIFESP: Teses e dissertações
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Microdomaines ordonnés de la membrane plasmique végétale : caractérisation et rôle dans la signalisation associée à la défense / Plant plasma membrane ordered domains : caracterization during defense signaling cascade

Grosjean, Kevin 02 June 2015 (has links)
Au cours de ces dernières années, des études ont montré l’existence d’une compartimentation latéraledes composants de la membrane plasmique végétale, de manière analogue à ce qui avait été montréchez les animaux et les levures. L’objectif de cette thèse était d’apporter de nouveaux éléments decaractérisation de cette compartimentation (propriétés physiques de domaines particuliers, mécanismesde mise en place de ces domaines, de contrôle de leur taille, etc…) et d’étudier son rôle dans laphysiologie de la cellule végétale.Le développement d’une méthodologie de microscopie confocale spectrale couplée à l’utilisationd’une sonde environnementale a permis d’apporter la première description à l'échellesubmicrométrique de l’organisation du plasmalemme en territoires aux propriétés physiquesdifférentiées. Ces domaines coexistent au sein de la membrane plasmique de cellules en suspension,comme à celle de membranes artificielles composées de lipides modèles ou de lipides de membranescellulaires, de vésicules géantes constituées de membrane plasmique purifiée, ou de protoplastes.Cependant, les différences de l’organisation latérale observées chez ces différentes membranes ontpermis de montrer l’importance des phytostérols qui seraient, par le biais d'interactions spécifiquesavec d’autres lipides végétaux tels que les GIPCs, des composés essentiels pour la formation locale dedomaines lipidiques ordonnés. La grande diversité des lipides végétaux organiserait ainsi lacompartimentation de la membrane plasmique permettant la ségrégation dynamique des composantsmembranaires. Si les stérols augmentent de manière importante le degré de compaction de la bicouche,les protéines le diminuent. Le cytosquelette et la paroi ne semblent, quant à eux, modifier ni laprésence, ni l’organisation des domaines ordonnés de la membrane plasmique. Nous avons égalementmontré que l’organisation de ces domaines évolue transitoirement lors des étapes précoces de lacascade de signalisation induite par des réactions de défense. De fait, nous avons identifié desmodifications des propriétés physiques globales et de l’organisation fine de la membrane provoquéespar différents éliciteurs de réactions de défense, dont la cryptogéine, une protéine sécrétée parl’oomycète Phytophthora cryptogea. Nous avons montré que ces modifications sont un élémentgénérique de la signalisation de défense, sous la dépendance de phénomènes de phosphorylation, leburst oxydatif étant également une étape clé de l’augmentation du degré d’ordre observé dans lesphases précoces de cette signalisation. La cryptogéine, qui présente une aptitude singulière pour piégerles stérols, a également montré une capacité spécifique à augmenter la fluidité membranaire, ceparamètre pouvant contrôler l’intensité de la cascade de signalisation, mesurée par la production deformes actives d’oxygène.Ces résultats ouvrent de nouvelles perspectives dans la compréhension des interactions cellule-élicitineet apportent un nouvel éclairage sur le rôle des lipides végétaux dans l’organisation latérale de lamembrane plasmique végétale et positionne la dynamique membranaire comme un élément designalisation de défense des plantes. / Recent studies have shown the existence of lateral sub-compartmentalization of plant plasmamembrane similar to that of animal cells and yeasts. The aim of this thesis was to provide newelements to characterize this compartmentalization (physical properties of specific domains,mechanisms of their formation, determination of their size, etc...) and to study its role in thephysiology of plant cells.The development spectral confocal microscopy coupled with the use of an environment-sensitiveprobe enabled to obtain the first description at the submicron scale of plasma membrane organizationinto domains exhibiting various physical properties. These domains coexist at the plasma membranesurface of tobacco suspension cells as well as the membrane of vesicles composed of models lipids orcell plasma membrane lipids, purified plasma membrane vesicles, and protoplasts. However,differences in the lateral organization observed in these membranes have shown the importance ofphytosterols which are, through specific interactions with neighboring plant lipids such as GIPCs,essential for local formation of ordered domains. The huge diversity of plant lipids drives thecompartmentalization of the plasma membrane allowing the dynamic segregation of membranecomponents. Sterols greatly increase membrane order, whereas proteins tends to decrease it.Cytoskeleton and cell wall do alter neither presence nor organization of ordered domains of the plasmamembrane. We have also shown that the organization of these domains is transiently modified duringthe early stages of defense signaling cascade. In fact, we have identified changes in overall physicalproperties and fine lateral organization of the membrane caused by various elicitors of defensereactions, including cryptogein, a protein secreted by the oomycete Phytophthora cryptogea. We haveshown that these changes are a generic element of defense signaling cascade and depend onphosphorylation processes; oxidative burst being also a major actor of the control of the increase ofmembrane order observed during the very early stages of the signalling process. Cryptogein, whichexhibits the particular ability to trap sterols, also showed a specific capacity to increase membranefluidity and amplify the intensity of the signalling cascade, as measured by the production of reactiveoxygen species.These results open new perspectives in the understanding of cell-elicitin interactions and provide anew view on the central role of sterol composition in the lateral organization of plant plasmamembrane. They also identify membrane dynamics as a new player in the signalling cascade occurringduring plant defense.

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