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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

Fucana ativa via das Map quinases e inibe a prolifera??o de c?lulas de ov?rio de hamster chin?s (CHO)

Nobre, Leonardo Thiago Duarte Barreto 08 July 2011 (has links)
Made available in DSpace on 2014-12-17T14:03:37Z (GMT). No. of bitstreams: 1 LeonardoTDBN_DISSERT_parcial.pdf: 2023324 bytes, checksum: af543040ab580eb729ea0ba7ac05cd5a (MD5) Previous issue date: 2011-07-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Fucan is a term used to denominate L-fucose rich sulfated polysaccharides. The fucans have been studied due their pharmacological activities like antithrombotic, antiproliferative and antioxidant. We have extracted three fucan fractions from the brown seaweed Spatoglossum schr?ederi. These fucans were denominated Fuc B 1, Fuc B 1.5 and Fuc B 2. The chemical analyzes show that the fucans have very similar composition as demonstrated by agarose electrophoresis gel, sugar and sulfate content. The antiproliferative effect was determined by MTT and BrdU methodologies in CHO cells. The inhibition of proliferation effect of the three fractions was about 40%. Therefore this we proceed just with the Fuc B 2 due the higher yield. There is no apoptosis indication using the anexin V/propidium iodide test. We found a cell cycle phase G1 arrest. The western blotting show that the PKC; pFAK; pERK 1/2 are activated when the cells were treated with fucans. The treatement with inhibitor of MAPK PD98059 extinguished the fucan effect. These results indicates that fucan act by the ERK pathway inducing the cell death. / Fucana ? um termo utilizado para denominar polissacar?deos sulfatados ricos em L-Fucose. As fucanas t?m sido estudadas devido suas atividades farmacol?gicas: antitromb?tica, antiproliferativa e antioxidante. N?s extra?mos tr?s fra??es de fucanas da alga Spatoglossum schr?ederi. Essas fucanas, denominadas de Fuc B 1, Fuc B 1.5 e Fuc B 2, apresentam uma composi??o muito similar como demonstrado pela eletroforese em gel de agarose, e conte?do de a??car e sulfato. O efeito antiproliferativo foi determinado pelas metodologias de MTT e BrdU em c?lulas CHO. O efeito na inibi??o da prolifera??o das tr?s fra??es foi de cerca de 40%. Assim, procedemos somente com a Fuc B 2 devido seu maior rendimento. N?o houve indica??o de apoptose usando a marca??o com anexina V-FITC/ Iodeto de Prop?deo. Identificamos uma parada na fase G1 do ciclo celular. Os ensaios de western blotting mostraram que PKC, pFAK e pERK 1/2 s?o ativadas quando as c?lulas s?o tratadas com Fuc B. O tratamento com o inibidor de MAPK PD98059 aboliu o efeito da fucana. Esses efeitos indicam que a fucana age via ERK para inibir a prolifera??o das c?lulas.
12

Caracteriza??o f?sico-qu?mica e a??es farmacol?gicas hepatoprotetora, antiinflamat?ria, pr?-angiog?nica, antioxidante e anticoagulante da fra??o rica em fucana 0,8FRF 0,8 da alga marrom Lobophora variegata

Will, Luiza Sheyla Evenni Porf?rio 21 December 2012 (has links)
Made available in DSpace on 2014-12-17T14:03:40Z (GMT). No. of bitstreams: 1 LuizaSEPW_DISSERT.pdf: 2731256 bytes, checksum: a154afda557a95d39d943b76672810db (MD5) Previous issue date: 2012-12-21 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study examines the physical and chemical composition and the pharmacological effects of brown seaweed FRF 0.8 Lobophora variegata. Fractionation of the crude extract was done with the concentration of 0.8 volumes of acetone, obtaining the FRF 0.8. The physicochemical characterization showed that it was a fucana sulfated. Anti-inflammatory activity was assessed by paw edema model by the high rates of inhibition of the edema and the best results were in the fourth hour after induction (100 ? 1.4% at the dose of 75 mg / kg) and by the strong inhibitory activity of the enzyme myeloperoxidase (91.45% at the dose of 25 mg / kg). The hepataprote??o was demonstrated by measurements of enzymatic and metabolic parameters indicative of liver damage, such as bilirubin (reduction in 68.81%, 70.68% and 68.21% for bilirubin total, direct and indirect, respectively at a dose of 75 mg / kg), ALT, AST and γ-GT (decrease of 76.93%, 44.58% and 50% respectively at a dose of 75 mg / kg) by analysis of histological slides of liver tissue, confirming that hepatoprotective effect the polymers of carbohydrates, showing a reduction in tissue damage caused by CCl4 and the inhibition of the enzyme complex of cytochrome P 450 (increasing sleep time in 54.6% and reducing the latency time in 71.43%). The effectiveness of the FRF 0.8 angiogenesis was examined in chorioallantoic membrane (CAM) of fertilized eggs, with the density of capillaries evaluated and scored, showing an effect proangig?nico at all concentrations tested FRF (10 mg- 1000 mg). The FRF showed antioxidant activity on free radicals (by inhibiting Superoxide Radical in 55.62 ? 2.10%, Lipid Peroxidation in 100.15 ? 0.01%, Hydroxyl Radical in 41.84 ? 0.001% and 71.47 Peroxide in ? 2.69% at concentration of 0.62 mg / mL). The anticoagulant activity was observed with prolongation of activated partial thromboplastin time (aPTT) at 50 mg (> 240 s), showing that its action occurs in the intrinsic pathway of the coagulation cascade. Thus, our results indicate that these sulfated polysaccharides are an important pharmacological target / Este estudo analisa a composi??o f?sico-qu?mica e os efeitos farmacol?gicos da FRF 0,8 da alga marrom Lobophora variegata. O fracionamento do extrato bruto foi feito com a concentra??o de 0,8 volumes de acetona, obtendo a FRF 0,8. A caracteriza??o f?sico-qu?mica mostrou que se tratava de uma fucana sulfatada. Foi verificada a atividade antinflamat?ria pelo modelo de edema de pata, atrav?s das altas taxas de inibi??o do edema e os melhores resultados foram na quarta hora ap?s a indu??o (100 ? 1,4% com a dose de 75 mg/kg) e pela forte atividade inibidora da enzima mieloperoxidase (91,45% com a dose de 25 mg/kg). A hepataprote??o foi demonstrada pelas dosagens de par?metros metab?licos e enzim?ticos indicativos de dano hep?tico, como bilirrubina (redu??o em 68,81%, 70,68% e 68,21% para bilirrubinas total, direta e indireta, respectivamente na dose de 75 mg/kg), ALT , AST e γ-GT (diminui??o em 76,93%, 44,58% e 50%, respectivamente na dose de 75 mg/kg), pela an?lise das l?minas histol?gicas do tecido hep?tico, que confirmam esse efeito hepatoprotetor dos pol?meros de carboidrato, mostrando uma redu??o no dano tecidual causado por CCl4, e pela inibi??o do complexo enzim?tico do citocromo P 450 (aumentando o tempo de sono em 54,6% e reduzindo o tempo de lat?ncia em 71,43%). A efic?cia sobre a angiogenese da FRF 0,8 foi examinada na membrana corioalant?ica (CAM) de ovos fertilizados, com a densidade dos capilares avaliadas e pontuadas, mostrando um efeito proangig?nico em todas as concentra??es de FRF testadas (10 μg-1000 μg). A FRF apresentou a??o antioxidante sobre radicais livres (inibindo o Radical Super?xido em 55,62?2,10%, Peroxida??o Lip?dica em 100,15?0,01%, Radical Hidroxila em 41,84?0,001% e Per?xido em 71,47?2,69%, todos na concentra??o de 0,62 mg/mL). A atividade anticoagulante foi verificada com o prolongamento do tempo de tromboplastina parcial ativada (aPTT) a 50 μg (>240 s), mostrando que sua a??o ocorre na via intr?nseca da cascata de coagula??o. Sendo assim, nossos resultados indicam que estes polissacar?deos sulfatados constituem um importante alvo farmacol?gico
13

Identifica??o e avalia??o de propriedades de polissacar?deos sulfatados de diferentes fontes naturais que possibilitem sua aplicabilidade biotecnol?gica

Santos, Nednaldo Dantas dos 19 March 2012 (has links)
Made available in DSpace on 2014-12-17T14:13:41Z (GMT). No. of bitstreams: 1 NednaldoDS_TESE.pdf: 2321205 bytes, checksum: c08caa8155a3fd7b840048363939c371 (MD5) Previous issue date: 2012-03-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Sulfated polysaccharides (SP) are widely distributed in animals and seaweeds tissues. These polymers have been studied in light of their important pharmacological activities, such as anticoagulant, antioxidant, antitumoral, anti-inflammatory, and antiviral properties. On other hand, SP potential to synthesize biomaterials like as nanoparticules has not yet been explored. In addition, to date, SP have only been found in six plants and all inhabit saline environments. However, the SP pharmacological plant activities have not been carrying out. Furthermore, there are no reports of SP in freshwater plants. Thus, do SP from marine plants show pharmacological activity? Do freshwater plants actually synthesize SP? Is it possible to synthesize nanoparticles using SP from seaweed? In order to understand this question, this Thesis was divided into tree chapters. In the first chapter a sulfated polysaccharide (SPSG) was successfully isolated from marine plant Halodule wrightii. The data presented here showed that the SPSG is a 11 kDa sulfated heterogalactan contains glucose and xylose. Several assays suggested that the SPSG possessed remarkable antioxidant properties in different in vitro assays and an outstanding anticoagulant activity 2.5-fold higher than that of heparin Clexane? in the aPTT test; in the next chapter using different tools such as chemical and histological analyses, energy-dispersive X-ray analysis (EDXA), gel electrophoresis and infra-red spectroscopy we confirm the presence of sulfated polysaccharides in freshwater plants for the first time. Moreover, we also demonstrate that SP extracted from E. crassipes root has potential as an anticoagulant compound; and in last chapter a fucan, a sulfated polysaccharide, extracted from the brown seaweed was chemically modified by grafting hexadecylamine to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed nanosized particles. The degree of substitution for hydrophobic chains of 1H NMR was approximately 93%. SNFfuc-TBa125 in aqueous media had a mean diameter of 123 nm and zeta potential of -38.3 ? 0.74 mV, measured bydynamic light scattering. Tumor-cell (HepG2, 786, H-S5) proliferation was inhibited by 2.0 43.7% at SNFuc concentrations of 0.05 0.5 mg/ mL and RAEC non-tumor cell line proliferation displayed inhibition of 8.0 22.0%. On the other hand, nanogel improved CHO and RAW non-tumor cell line proliferation in the same concentration range. Flow cytometric analysis revealed that this fucan nanogel inhibited 786 cell proliferation through caspase and caspaseindependent mechanisms. In addition, SNFuc blocks 786 cell passages in the S and G2-M phases of the cell cycle / Os polissacar?deos sulfatados (PS) s?o amplamente distribu?dos em animais e tecidos de algas. Estes pol?meros t?m sido estudados em fun??o da import?ncia de suas atividades farmacol?gicas, tais como: anticoagulante, antioxidante, antitumoral, anti-inflamat?ria e as propriedades antivirais. Contudo, o potencial dos PS para sintetizar biomateriais, tais como nanopart?culas, ainda ? pouco explorado. At? ent?o, os PS s? foram encontrados em seis plantas e todas habitam ambientes salino. N?o havendo relatos de PS em plantas de ?gua doce. O que nos levou aos seguintes questionamentos: Os PS extraidos de vegetais marinhos n?o apresentam atividades farmacol?gicas? Os vegetais de ?gua doce realmente sintetizam PS? ? poss?vel sintetizar nanopart?culas utilizando PS a partir de algas marinhas? Para melhor entender as quest?es, esta tese foi dividida em tr?s cap?tulos. No primeiro cap?tulo, um polissacar?deo sulfatado (SPSG) foi isolado a partir de um vegetal marinho Halodule wrightii. Os dados aqui apresentados mostram que o SPSG ? uma heterogalactana sulfatada de 11 kDa constituida de glucose e xilose. Os ensaios realizados sugerem que o SPSG possue propriedades antioxidantes not?veis em diferentes ensaios in vitro e uma excelente actividade anticoagulante de 2,5 vezes mais elevadas do que a de heparina Clexane ? no teste APTT. No cap?tulo seguinte, utilizando ferramentas diferentes, tais como an?lises qu?micas e histol?gicas, an?lise de dispers?o de raios-X (EDXA), eletroforese em gel e espectroscopia de infra-vermelho,confirmamos, em primeira m?o, a presen?a de polissacar?deos sulfatados em vegetais de ?gua doce. Al?m de demonstrarmos que o PS extra?do a partir da raiz de E. crassipes tem potencial como um composto anticoagulante.No ?ltimo cap?tulo uma fucana, um polissac?rido sulfatado, extra?do a partir de uma alga marrom, foi quimicamente modificada por adi??o de hexadecilamina ? cadeia principal do pol?mero hidrof?lico. O material resultante (SNFuc) forneceu part?culas nanom?tricas. O grau de substitui??o para as cadeias hidrof?bicas de 1H RMN foi de aproximadamente 93%. SNFuc em meios aquosos tinha um di?metro m?dio de 123 nm e potencial zeta de -38,3 ? 0,74 mV. Os ensaios com c?lulas tumorais (HepG2, 786, H-S5) demonstrou a ocorr?ncia de uma inibi??o que variou de 2,0-43,7% em concentra??es diferentes de SNFuc (0,05-0,5 mg / mL) resultado semelhante foi obtido com a RAEC monstrando uma inibi??o entre 8,0-22,0%. Por outro lado, o nanogel estimulou a prolifera??o de linhagens celulares n?o tumorais como CHO e RAW nas mesmas concentra??es. An?lise por citometria de fluxo revelou que este nanogel de fucana inibiu a prolifera??o celular de 786 por mecanismos dependentes e independentes de caspases. Al?m disso, bloqueou a passagens da c?lula 786 na fase S e G2-M do ciclo celular / 2020-01-01

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