Submitted by Cássio da Cruz Nogueira (cassionogueirakk@gmail.com) on 2017-01-31T12:02:52Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EfeitoInVitroCompontentes.pdf: 2228394 bytes, checksum: 46bea600f7906285cf48b07bdc8d017d (MD5) / Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2017-02-01T12:08:00Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EfeitoInVitroCompontentes.pdf: 2228394 bytes, checksum: 46bea600f7906285cf48b07bdc8d017d (MD5) / Made available in DSpace on 2017-02-01T12:08:00Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_EfeitoInVitroCompontentes.pdf: 2228394 bytes, checksum: 46bea600f7906285cf48b07bdc8d017d (MD5) Previous issue date: 2014-10-20 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A hanseníase é uma doença infecciosa que ainda representa uma preocupação na saúde pública mundial no século XXI. A poliquimioterapia preconizada pela Organização Mundial de Saúde (OMS), apesar de ser a barreira mais eficaz no combate ao Mycobacterium leprae, é um dos responsáveis pela produção de EROs e desenvolvimento de metemoglobinemia e anemia hemolítica nos pacientes em tratamento. Nesse sentido, o objetivo desse trabalho foi verificar os possíveis danos oxidativos em pacientes hansenianos em uso de poliquimioterapia (PQT), ao avaliar parâmetros hematológicos e o perfil oxidativo em eritrócitos, e detectar os efeitos do tratamento in vitro com os antioxidantes resveratrol (RSV) e ácido alfa-lipoico (ALA) na prevenção da metemoglobinemia e na atividade de enzimas antioxidantes. Os resultados obtidos demonstraram diminuição dos valores de hemácias e reticulocitose nos pacientes entre o quarto e o sétimo mês de tratamento com PQT, comparados aos valores encontrados no grupo controle. A formação de metemoglobina (MetHb) aumentou a partir do 5º mês de tratamento com PQT, e a utilização de RSV e ALA na concentração de 100 μM manteve o percentual de MetHb somente em amostras de pacientes que estavam entre o 4º e 6º mês de uso de PQT. Observou-se nos pacientes hansenianos uma atividade de SOD similar ao controle e uma decrescida atividade de CAT, o que possivelmente implica maior produção de H2O2. O tratamento com RSV e ALA nas concentrações de 100 e 500 μM elevou em duas vezes a atividade de SOD em amostras de pacientes na 4ª dose de PQT; no entanto, não alterou a atividade enzimática de CAT e SOD observada nos pacientes com hanseníase. Dessa forma, os resultados descritos sugerem que os antioxidantes RSV e ALA, nas concentrações testadas in vitro, não mostram atividade antioxidante quando utilizados em situações de estresse oxidativo previamente estabelecidas, porém estudos posteriores são necessários para verificar os efeitos dose e tempo-dependentes de RSV e ALA como prevenção de danos oxidativos nas doenças infecciosas crônicas. / The leprosy is an infectious disease that represents a major preoccupation in global public health in 21st century. The treatment with Multi Drug Therapy (MDT) approved by the World Health Organization (WHO) is the best treatment to Mycobacterim leprae infection; however, is one of the factors of increasing Reactive Oxygen Species (ROS) production and the development of methemoglobinemia and hemolytic anemia in these patients. The aim of this study was to verify the oxidative damage in leprosy patients receiving MDT, by evaluation of hematological and oxidative stress biomarkers, and identify the effects of in vitro treatment with antioxidants alpha-lipoic acid (ALA) and resveratrol (RSV) in antioxidant enzymes activity and prevention of methemoglobinemia. The results revealed a decrease in RBC count and reticulocytosis in patients receiving MDT during the 4th and 7th month of treatment. The percentual of methemoglobin increased since the fifth month of treatment with MDT, and the treatment with 100 μM RSV-treated and ALA-treated preserved the values similar to control group only in 4th to 6th month of MDT samples. The leprosy patients presented values of SOD activity similar to the control group and a decreased CAT activity, leading to an inbalance in the ratio of both enzymes and possibly resulting in an over-producing of H2O2. The treatment with RSV and ALA in 100 μM and 500 μM concentrations increases twice the SOD activity in 4th month patient samples; however, these concentrations did not change CAT and SOD activities found in leprosy patients. Such results demonstrate that RSV and ALA did not show antioxidant activity in installed oxidative stress, and subsequent studies are necessary to evaluate dose-dependent and time-dependent concentrations of RSV and ALA to prevent oxidative damage in chronic infectious diseases.

The lens of the eye needs to be transparent with a high refractive index to focus images on the retina. In cataracts the lens becomes opaque, eventually leading to blindness. There are many possible causes of cataract but a lot of evidence implicates oxidative damage as contributing to opacification. This includes epidemiological studies showing that diets rich in antioxidants lowered the prevalence of cataract. This research tested the hypothesis that if cataracts were at least partially caused by oxidative damage then their progression would be slowed by application of antioxidants. The antioxidants used were two plant compounds found in the diet, resveratrol and quercetin. The system used was sheep lenses cultured in Eagles Minimal Essential Medium (EMEM). Lenses remained transparent for up to 7 days in EMEM but became opaque within 24 h when exposed to 1 mM hydrogen peroxide (H2O2). The lens is exposed to H2O2 in vivo as it is found in the aqueous humor. Prior Lenses pre-treated with quercetin reduced but did not prevent opacification. Lens cell death, as determined by measurement of leakage of lactate dehydrogenase, was found to increase with H2O2 and the increase was prevented by pre-treatment with antioxidants. The role of the endogenous antioxidant glutathione was also investigated. It was found that H2O2 decreased the amount of reduced glutathione in the lens cortex and increased the levels of oxidised glutathione but only at levels of 2 mM and above. Thus the results of this research indicate that H2O2 at low concentration (1 mM) is able to damage lens cells and cause opacification without affecting the reduced glutathione levels and that the exogenous antioxidants have some ability to protect the lens.

Clay minerals have historically played a consequential role in human health. While the beginnings were rooted in geophagy, a primitive act of consuming earth, the health-related uses of clay minerals have evolved and diversified over time. As excipients in pharmaceutical formulations, clay minerals can attribute novel properties onto intercalated compounds. Intercalating oxybenzone, a UV filter, within the interlamellar space of montmorillonite is desirable in order to minimize direct contact with skin. Intercalating resveratrol, a compound known for attributing beneficial effects onto human health, may be advantageous since this compound is susceptible to cis-trans isomerisation. The strategy of using alkylammonium–modified clay was undertaken and proved successful for the intercalation of oxybenzone. The field of biopolymer/layered silicate nanocomposites is heavily researched for use in a multitude of applications. Novel montmorillonite nanocomposites were prepared with neutral guar gum and cationic guar gum, using an environmentally friendly process and are fully characterized.

Clay minerals have historically played a consequential role in human health. While the beginnings were rooted in geophagy, a primitive act of consuming earth, the health-related uses of clay minerals have evolved and diversified over time. As excipients in pharmaceutical formulations, clay minerals can attribute novel properties onto intercalated compounds. Intercalating oxybenzone, a UV filter, within the interlamellar space of montmorillonite is desirable in order to minimize direct contact with skin. Intercalating resveratrol, a compound known for attributing beneficial effects onto human health, may be advantageous since this compound is susceptible to cis-trans isomerisation. The strategy of using alkylammonium–modified clay was undertaken and proved successful for the intercalation of oxybenzone. The field of biopolymer/layered silicate nanocomposites is heavily researched for use in a multitude of applications. Novel montmorillonite nanocomposites were prepared with neutral guar gum and cationic guar gum, using an environmentally friendly process and are fully characterized.

Clay minerals have historically played a consequential role in human health. While the beginnings were rooted in geophagy, a primitive act of consuming earth, the health-related uses of clay minerals have evolved and diversified over time. As excipients in pharmaceutical formulations, clay minerals can attribute novel properties onto intercalated compounds. Intercalating oxybenzone, a UV filter, within the interlamellar space of montmorillonite is desirable in order to minimize direct contact with skin. Intercalating resveratrol, a compound known for attributing beneficial effects onto human health, may be advantageous since this compound is susceptible to cis-trans isomerisation. The strategy of using alkylammonium–modified clay was undertaken and proved successful for the intercalation of oxybenzone. The field of biopolymer/layered silicate nanocomposites is heavily researched for use in a multitude of applications. Novel montmorillonite nanocomposites were prepared with neutral guar gum and cationic guar gum, using an environmentally friendly process and are fully characterized.

Duchenne Muscular Dystrophy (DMD) is an x-linked neuromuscular disease that is caused by an absence of dystrophin protein, rendering skeletal muscle more susceptible to contraction-induced damage. One therapeutic strategy focuses on increasing the expression of endogenous utrophin A, a dystrophin homologue. Interestingly, slow muscle is more resistant to the dystrophic pathology and has increased utrophin A expression (Webster 1998; Gramolini 2001b). These observations led researchers to explore the therapeutic potential of stimulating the slow, oxidative myogenic program (SOMP) in the mdx context. Beneficial adaptations were seen with pharmacological activation of PPARδ and AMPK. We treated mdx mice with resveratrol (~100mg/kg/day), a putative SIRT1 activator, for 6-7 weeks and evaluated the activity of phenotypic modifiers that are known to influence the SOMP. SIRT1 activity and protein levels increased significantly, as well as downstream PGC-1α activity. There was evidence of a fibre type conversion as the treated mice had a higher proportion of the slow myosin heavy chain isoforms in both the EDL and Soleus skeletal muscles. Utrophin A protein levels showed modest, but consistent increases with resveratrol treatment. Finally, histological analysis revealed improvements in central nucleation and fibre size variability. These findings were promising, but raised the question of whether modifying the treatment regimen may result in greater therapeutic benefits. Surprisingly, we discovered that an elevated dose of 500mg/kg/day was ineffective in its promotion of the SOMP. SIRT1 was not activated and there was no change in utrophin A levels with resveratrol treatment. Taken together, this study demonstrates that resveratrol has the ability to promote the SOMP through SIRT1 and PGC-1α activation. It also highlights the importance of selecting an appropriate dose of resveratrol to maximize its effectiveness.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-12-12T18:27:28Z No. of bitstreams: 1 EnioRafaelDeMedeirosSantos_TESE.pdf: 2342949 bytes, checksum: 3af05779dbf2fc774f0fc56044099d59 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-12-13T20:32:49Z (GMT) No. of bitstreams: 1 EnioRafaelDeMedeirosSantos_TESE.pdf: 2342949 bytes, checksum: 3af05779dbf2fc774f0fc56044099d59 (MD5) / Made available in DSpace on 2017-12-13T20:32:49Z (GMT). No. of bitstreams: 1 EnioRafaelDeMedeirosSantos_TESE.pdf: 2342949 bytes, checksum: 3af05779dbf2fc774f0fc56044099d59 (MD5) Previous issue date: 2017-09-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Pesquisas apresentam o excesso de radicais livres como um dos respons?veis por diversas doen?as degenerativas e pelo envelhecimento. Nesse contexto, desponta a utiliza??o de compostos fen?licos naturais por apresentarem ?tima atividade antioxidante e por inibirem a forma??o desses radicais. Em meio aos estudos acerca desses compostos, os antioxidantes: cis e trans-resveratrol, cis e trans-piceid e emodina ganham destaque no meio cient?fico. Trabalhos cient?ficos comprovam a presen?a desses compostos fen?licos na herb?cea ?Azedinha? (Rumex acetosa), logo, os extratos de suas ra?zes v?m sendo cada vez mais utilizadas em aplica??es farmacol?gicas. A partir disso, este trabalho teve por objetivo central a obten??o de extratos dessas ra?zes utilizando t?cnicas de extra??o com fluido supercr?tico (SFE), extra??o com l?quidos pressurizados (PLEs), extra??o com utiliza??o de micro-ondas (MAE), extra??o com solvente a baixa press?o (LPSE) e a extra??o Soxhlet. Na SFE, foi avaliado o efeito das vari?veis de processo (temperatura, vaz?o, press?o e concentra??o de cossolvente) sobre a cin?tica da extra??o, rendimento e solubilidade do extrato. Nas PLEs, tanto foram avaliadas a temperatura e a press?o, como a influ?ncia dos diferentes solventes (?gua, etanol, hexano, tolueno, acetonitrila e isopropanol) e seu uso sequenciado como PLE sequenciada. As curvas obtidas nas SFEs e PLEs foram ajustadas segundo os modelos: Mart?nez, Crank e Sovov? e seus desvios m?dios calculados. Na extra??o Soxhlet foi avaliado o uso de quatro solventes (etanol, acetonitrila, isopropanol e ?lcool terc-but?lico), enquanto que na extra??o LPSE e MAE foi utilizado o etanol como solvente. Tamb?m foi testada a utiliza??o da precipita??o por anti-solvente supercr?tico (SAS) como forma de secagem. O teor de fen?licos totais, a capacidade antioxidante dos extratos e os principais componentes do extrato foram determinados. Os rendimentos obtidos em todas as t?cnicas variaram de 0,2 a 8,7%, sendo o melhor resultado obtido na extra??o PLE com etanol. A SFE apresentou o extrato com maior concentra??o de emodina (42,8 mg/g). A concentra??o de trans-resveratrol em todos os extratos variou entre 1,0 e 5,7 mg/g, a depender da t?cnica utilizada. A atividade antioxidante e os compostos fen?licos totais resultaram em valores compreendidos entre 3,4 e 163,4 ?g/mL e 27,6 e 157,0 mg EAG/ge, respectivamente, a depender da t?cnica utilizada. A MAE obteve extratos com 130,6 mg EAG/ge, e 3,4 ?g/mL em 30 minutos de opera??o. As extra??es com fluidos pressurizados (PLEs e SFEs) demonstraram ?timos resultados, principalmente quanto ? extra??o sequencial, na qual foi poss?vel a separa??o de trans-resveratrol e emodina. / Research presents the excess of free radicals as one responsible for various degenerative diseases and aging. In this context, the use of natural phenolic compounds appears to have excellent antioxidant activity and to inhibit the formation of these radicals. In the middle of studies about these compounds, the antioxidants: cis and trans-resveratrol, cis and trans-piceid and emodin are prominent in the scientific world. Scientific works prove the presence of these phenolic compounds in the herbaceous "Azedinha" (Rumex acetosa), so extracts from their roots have been increasingly used in pharmacological applications. From this, the main objective of this work was to extract extracts of these roots using supercritical fluid extraction (SFE), pressurized fluid extraction (PLEs), microwave extraction (MAE), solvent extraction low pressure (LPSE) and Soxhlet extraction. In SFE, the effect of the process variables (temperature, flow, pressure and cosolvents concentration) on the kinetics of extraction, yield and solubility of the extract was evaluated. In the PLEs, both temperature and pressure and the influence of the different solvents (water, ethanol, hexane, toluene, acetonitrile and isopropanol) were evaluated and their use sequenced as PLE. The curves obtained in the SFEs and PLEs were adjusted according to the models: Mart?nez, Crank and Sovov? and their calculated mean deviations. In the Soxhlet extraction, the use of four solvents (ethanol, acetonitrile, isopropanol and tert-butyl alcohol) was evaluated, while in the LPSE and MAE extraction ethanol was used as the solvent. The use of supercritical anti-solvent (SAS) precipitation as a drying method was also tested. The total phenolic content, the antioxidant capacity of the extracts and the main components of the extract were determined. The yields obtained in all the techniques varied from 0.2 to 8.7%, being the best result obtained in the PLE extraction with ethanol. SFE presented the extract with the highest concentration of emodin (42.8 mg/g). The concentration of trans-resveratrol in all extracts ranged from 1.0 to 5.7 mg/g, depending on the technique used. The antioxidant activity and the total phenolic compounds resulted in values between 3.4 and 163.4 ?g/mL and 27.6 and 157.0 mg EAG/g, respectively, depending on the technique used. MAE obtained extracts with 130.6 mg EAG/g and 3.4 ?g/mL in 30 minutes of operation. Extractions with pressurized fluids (PLEs and SFEs) showed excellent results, mainly regarding sequential extraction, in which the separation of trans-resveratrol and emodin was possible.

L’adénocarcinome pancréatique canalaire (PDAC) est un cancer de mauvais pronostic en partie en raison de la résistance aux traitements conventionnels de chimiothérapie ou de radiothérapie. Certaines substances bioactives issues de l’alimentation (BFCs), prooxydantes sont capables de potentialiser l’action cytotoxique des drogues conventionnelles dans le PDAC. Par ailleurs ces BFCs pourraient augmenter les cassures de l’ADN induites par les radiations ionisantes. Objectifs : évaluer l’action combinée de BFCs en association avec la chimiothérapie et la radiothérapie dans des modèles de PDAC et identifier les mécanismes impliqués dans la chimio/radiosensibilisation. Méthodes : La survie cellulaire a été évaluée in vitro en présence de BFCs en combinaison sur 4 lignées tumorales pancréatiques. La production d’espèces réactives de l'oxygène (ROS) a été mesurée par cytométrie en flux et par microscopie à fluorescence. Les mécanismes moléculaires ont été décryptés par western-blot (voies de signalisation) et cytométrie en flux (cycle cellulaire et apoptose). Enfin nous avons évalué l’association de BFCs en gavage avec la chimiothérapie par gemcitabine intrapéritonéale et avec la radiothérapie de 2 Gy par fraction in vivo, sur des greffes sous-cutanée de cellules CAPAN-2. Résultats : In vitro, le resvératrol (R), la capsaïcine (C) et le sulforaphane (S) étaient cytotoxiques avec effet inhibiteur significativement plus élevé en combinaison (R+C), (C+S) ou (R+C+S), sans effet sur les fibroblastes. Par ailleurs, les combinaisons potentialisaient l’action autrement limitée de la gemcitabine sur les cellules testées in vitro. In vivo, l’addition de R+C au traitement par gemcitabine à dose réduite a permis une régression tumorale équivalente à celle obtenue avec la gemcitabine à pleine dose. Par ailleurs, in vitro, l’ajout des BFCs seuls et combinés à la radiothérapie augmente de façon significative la toxicité cellulaire sur la lignée épithéliale CAPAN-2, comparé au traitement par radiothérapie seule comme aux traitements par BFCs seuls ou combinés. In vivo, la combinaison R+C associée à la radiothérapie a permis une diminution significative des volumes tumoraux comparée à la radiothérapie seule. L’étude des voies de signalisation a montré une augmentation de protéines pro-apoptotiques avec l’association R+C, en rapport avec une induction augmentée de ROS, mais aussi, de façon surprenante, une inhibition de la réparation de l’ADN par inhibition de la phosphorylation d’ATM. Ces deux effets combinés précipitaient la mort des cellules tumorales. Conclusions : Les combinaisons de R+C ont un effet chimiosensibilisant et radiosensibilisant dans un modèle préclinique de PDAC, avec des mécanismes moléculaires identifiés pertinents dans le contexte des thérapies testées. En associant les BFCs, à la chimioradiothérapie avec gemcitabine, on peut espérer une double potentialisation de la radiothérapie et de la chimiothérapie, en augmentant l’efficacité de la RT, et en diminuant la dose de gemcitabine associée pour une même efficacité et une meilleure tolérance du traitement.Mots clés : Cancer du pancréas, Substances bioactives issues de l’alimentation, radiothérapie, chimiothérapie, resvératrol, capsaïcine / Background: Pancreatic ductal adenocarcinoma (PDAC) is of poor prognosis in part because of resistance to conventional treatments such as chemotherapy or radiotherapy. Some naturally occurring bioactive food components (BFCs), with pro-oxidant properties are able to potentiate the cytotoxic action of conventional drugs in the PDAC. In addition, these BFCs could increase the DNA breaks induced by ionizing radiation. Objectives: To evaluate the combined action of several BFCs in combination with chemotherapy and radiotherapy in PDAC models and to identify mechanisms involved in chemo / radiosensitization at the cellular and molecular levels. Methods: Cell survival was evaluated in vitro in the presence of BFCs in combination on 4 pancreatic tumor cell lines. The production of reactive oxygen species (ROS) was measured by flow cytometry and fluorescence microscopy. Molecular mechanisms have been decrypted by western blot (signaling pathways) and flow cytometry (cell cycle and apoptosis). Finally, we evaluated the association of BFCs in gavage with intraperitoneal gemcitabine chemotherapy and with radiotherapy (2 Gy/fraction) in vivo, on subcutaneous CAPAN-2 cell xenografts. Results: In vitro, resveratrol (R), capsaicin (C) and sulforaphane (S) were cytotoxic with significantly higher inhibitory effect in combination (R + C), (C + S) or (R + C + S), without effect on fibroblasts. In addition, the combinations potentiated the otherwise limited action of gemcitabine on cells tested in vitro. In vivo, the addition of R + C to treatment with gemcitabine at reduced dose allowed tumor inhibition equivalent to that obtained with gemcitabine at full dose. Furthermore, in vitro, the addition of BFCs alone and in combination with radiotherapy significantly increases cellular toxicity on the CAPAN-2 epithelial line, compared to radiotherapy alone and BFCs alone or combined. In vivo, the combination R + C associated with radiotherapy allowed a significant decrease in tumor volumes compared to radiotherapy alone. The study of signaling pathways showed an increase of proapoptotic proteins with the association R + C and radiotherapy, in relation with an increased induction of ROS, but also, surprisingly, an inhibition of the repair of the DNA by inhibition of ATM phosphorylation. These two combined effects precipitated the death of the tumor cells. Conclusions: Combinations of R + C have a chemosensitizing and radiosensitizing effect in a preclinical model of PDAC, with identified molecular mechanisms relevant in the context of the therapies tested. By combining BFCs with radiochemotherapy with gemcitabine, we can hope for a double potentiation of radiotherapy and chemotherapy, by increasing the effectiveness of RT, and by reducing the dose of gemcitabine associated for similar efficiency and better tolerance treatment.

Submitted by Regina Correa (rehecorrea@gmail.com) on 2016-10-03T20:53:43Z No. of bitstreams: 1 TeseACBMM.pdf: 12490231 bytes, checksum: 097b90957f143d8d696733602a92d242 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-05T13:41:11Z (GMT) No. of bitstreams: 1 TeseACBMM.pdf: 12490231 bytes, checksum: 097b90957f143d8d696733602a92d242 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-05T13:41:20Z (GMT) No. of bitstreams: 1 TeseACBMM.pdf: 12490231 bytes, checksum: 097b90957f143d8d696733602a92d242 (MD5) / Made available in DSpace on 2016-10-05T13:48:36Z (GMT). No. of bitstreams: 1 TeseACBMM.pdf: 12490231 bytes, checksum: 097b90957f143d8d696733602a92d242 (MD5) Previous issue date: 2015-03-20 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Breast cancer is the leading cause of death in Brazil and worldwide, between the types of cancer, triple negative TNBC (Triple Negative Breast Cancer), which do not express hormone receptors, represents 20% of the cases and presents relapses within 3 years. However, the major cause of death in cancer is due the formation of metastasis. The TNBC has a greater propensity to form lung and brain metastasis. Furthermore, currently few treatments are available. Search for new target treatments, with fewer side effects is very important to treat this disease. Natural products are rich sources of molecules with antitumoral activity; among them are the gingerols, from ginger and resveratrol, from grapes. Nevertheless, not much is known about antitumor activity of [10]-gingerol (10G). Therefore, the aim of this work was to investigate the potential use of 10G as an antimetastatic molecule in in vitro and in vivo experiments. In this work, 10G had antiproliferative activity on several breast cancer cell lines (4T1BM2, 4T1BM2 shRNAβ3, 4T1Br4, MDA-MB-231, MDA-MB-231 BrM) and on a normal cell line, bEnd.3. The natural compounds affected tumor cell morphology and RSVT was able to inhibit cell migration and adhesion through vitronectin. 10G induced apoptosis via the extrinsic pathway through the increase of caspase-9, -3 and -7 expression and decrease of Bcl-2 expression, induced cell cycle arrest in G1 and subG0 phase. In in vivo models, 10G inhibited primary tumor growth and lung metastasis, as well as bone and brain metastasis. Therefore, this study was able to provide new data as 10G can be acting in tumor cells and its possible clinical application. / O câncer de mama é o que mais afeta as mulheres no Brasil e no mundo, entre os tipos de câncer de mama, o triplo negativo TNBC (Triple Negative Breast Cancer), que não expressa nenhum receptor hormonal, corresponde a 20% dos casos e apresenta recidivas em três anos. Entretanto, a maior causa de morte no câncer é devido a formação de metástases. O TNBC possui uma maior propensão a metástases pulmonares e cerebrais. Além disso, atualmente poucos tratamentos estão disponíveis. Buscas para novos medicamentos alvo para o TNBC e com menos efeitos colaterais são de grande importância para o tratamento dessa doença. Produtos naturais são fontes ricas em moléculas com atividades antitumorais, dentre elas os gingeróis, presentes no gengibre e o resveratrol (RSVT), presente nas uvas. Entretanto, pouco se sabe da atividade antitumoral do [10]-gingerol (10G). Este trabalho teve como objetivo investigar o potencial uso do 10G como molécula antimetastática em experimentos in vitro e in vivo. Neste trabalho verificou-se a atividade antiproliferativa do 10G e do RSVT em diversas linhagens de câncer de mama (4T1BM2, 4T1BM2 shRNAβ3, 4T1Br4, MDA-MB- 231, MDA-MB-231 BrM) e um controle de célula normal, a bEnd.3. Os produtos naturais (PNs) usados afetam a morfologia celular nas células tumorais e o RSVT é capaz de inibir a adesão e migração via vitronectina. O 10G induziu apoptose da linhagem 4T1Br4 através da via extrínseca, com o aumento da expressão de casspase-9, -3 e -7; induziu a parada do ciclo celular nas fases G1 e sub G0. Em modelos de metástase in vivo o 10G inibiu o crescimento do tumor primário e de metástases pulmonares, além de inibir metástases ósseas e cerebrais. Portanto, este trabalho foi capaz de fornecer dados de como o 10G atua nas células tumorais e sua possível aplicação clínica.

Dans cette thèse de doctorat, la structure de membranes naturelles et modèles et leurs interactions avec des molécules biologiquement actives ont été étudiées au moyen de la réflectométrie de neutrons. Les lipides naturels ont été extraits de la levure Pichia pastoris, poussée en milieux deutéré et hydrogéné. L’analyse a montré que la quantité relative de phospholipides n’est pas affectée par le changement en composition isotopique du milieu de croissance. Cependant, les cellules de levures deutérées contiennent principalement des acides gras C18 :1 alors que le degré d’insaturation est plus élevé chez les levures hydrogénés. Diminuer la température du milieu de croissance permet d’augmenter le degré d’insaturation des acides gras chez les levures deutérées. Une analyse qualitative des sphingolipides a été réalisée et un protocole pour séparer les fractions phosphocholines et phosphoethanolamine a été établi.<p><p>La structure de bicouches composées des lipides de levures a été étudiée par réflectivité de neutrons. La bicouche composée de lipides deutérés polaires a une épaisseur similaire aux bicouches faites de phosphocholines C18:1 synthétiques. En présence de stérols, la rugosité aux interfaces entre les têtes polaires et les chaînes augmente. La bicouche composée de lipides polaires hydrogénés est plus mince que celle deutérée. Ceci est dû à la composition en acides gras beaucoup plus variée et du plus grand nombre d’insaturations. En présence de stérols, l’épaisseur de la bicouche hydrogénée augmente. <p>L’interaction de ces bicouches avec l’amphotéricine B (AmB) a été étudiée. L’AmB est un antifongique qui interagit fortement avec les membranes contenant de l’ergostérol et moins fortement avec des membranes contenant du cholestérol. Dans tous les cas, les molécules d’AmB forment une couche épaisse et diluée au dessus de la bicouche lipidique. En présence de stérols, les molécules d’AmB pénètrent dans la bicouche et change sa structure selon la composition en acide gras.<p><p>La structure de bicouches lipidiques de plante et leurs interactions avec des intermédiaires de synthèse ont aussi été étudiées par réflectivité de neutrons. Des mélanges ternaires de plantes étaient déposés sur silicium et des mélanges quaternaires sur saphir. L’épaisseur de la bicouche composée de mélange ternaire est de 38 Å, tandis que celle du mélange ternaire est de 28 Å, la différence venant probablement d’un effet de substrat. La présence de diacylglycérol (DAG) a comme conséquence d’augmenter l’aire par lipide, et ainsi de changer la conformation des têtes polaires. L’interaction des bicouches de lipide de plante avec l’acide phosphatidique (PA) dans le but d’observer un flip-flop possible a aussi été étudiée mais le PA a tendance à désorbé les bicouches du substrat et aucun mécanisme de flip flop n’a été détecté.<p><p>Finalement, la localisation d’une petite molécule, le resvératrol, dans des bicouches modèles a été étudiée. Le resvératrol est connu pour être responsable du « paradoxe français » qui est une corrélation inverse entre la consommation d’aliment gras et un faible taux de maladie cardiaque. Quand le resvératrol est adsorbé à partir de la phase liquide, il induit une réorganisation des têtes polaires. Quand il est déposé sur le substrat en présence des lipides, il est présent à l’interface entre les têtes polaires et les chaines.<p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished