Orientador: Gisele Fabrino Machado / Banca:Valéria Marcal Felix de Lima / Banca: Suely Regina Mogami Bomfim / Banca: Paulo Ricardo Dell'Armelinda Rocha / Banca: Monica Regina Vendrame Amarante / Resumo: A leishmaniose visceral (LV) é uma doença que causa manifestações clínicas variadas em cães, incluindo alterações neurológicas, entretanto, existem poucos relatos que caracterizam as lesões observadas e que contribuem para elucidar a patogenia da forma neurológica da LV. O plexo coroide (PC) forma uma importante interface entre o liquor e o sistema periférico vascular, e é uma estrutura com potencial para permitir a passagem de células inflamatórias no sistema nervoso central além de servir como fonte de mediadores inflamatórios. O objetivo deste estudo foi avaliar as lesões encefálicas incluindo o PC em cães com LV e avaliar a possível participação do PC como estrutura produtora de mediadores pró-inflamatórios como citocinas (IL-1β, IL-6, INF-γ, TNF-α) e quimiocinas (CCL-3, CCL-4, CCL-5, CXCL-10), e disfunção da barreira hematoencefálica (BHE) através da presença de albumina, anticorpo anti- Leishmania no liquor e também pelo quociente de albumina o que poderia facilitar a passagem de células imunes e contribuir para as alterações inflamatórias encefálicas. Foi observado infiltrado inflamatório variando de leve a acentuado principalmente em PC e meninges. Aumento na expressão gênica de CCL-5 e tendência no aumento da CXCL-10 em PC de cães infectados. Presença de formas amastigotas e DNA de Leishmania no PC, além de anticorpos anti-Leishmania e albumina no liquor de cães com LV. Esses resultados indicam que há disfunção da BHE em cães com LV e que a CCL-5 poderia ser produzid... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract:Visceral leishmaniasis (VL) is a disease that causes several clinical manifestations in dogs, including neurological alterations, however, there are few reports that characterize the lesions observed and that contribute to elucidate the pathogenesis of the neurological form of VL. The choroid plexus (CP) forms an important interface between the cerebrospinal fluid and the vascular peripheral system, and is a structure with the potential to allow the passage of inflammatory cells into CNS and serve as a source of inflammatory mediators. The objective of this study was to evaluate brain lesions including CP in dogs with VL and to evaluate the possible participation of CP as a producer of pro-inflammatory mediators such as cytokines (IL-1β, IL-6, INF-γ, TNF-α) and chemokines (CCL-3, CCL-4, CCL-5, CXCL-10), and blood brain barrier (BBB) dysfunction through the presence of albumin, antibody anti-Leishmania in the cerebrospinal fluid and also by the albumin quotient facilitate the passage of immune cells and contribute to inflammatory brain disorders. Inflammatory infiltrates were observed ranging from mild to severe, mainly in CP and meninges. Increased gene expression of CCL-5 and tendency to increase CXCL-10 in CP from infected dogs. Presence of amastigotes and Leishmania DNA in CP, as well as anti-Leishmania antibodies and albumin in the cerebrospinal fluid of dogs with VL. These results indicate that there is dysfunction of BBB in dogs with VL and that CCL-5 could be produced by CP, on the other hand, this tissue did not prove to actively contribute to the production of other cytokines evaluated in this study / Doutor

Magister Pharmaceuticae - MPharm / Recent scientific findings have highlighted the beneficial roles of polycyclic cage compounds in neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Further interest into the chemistry of these compounds is stimulated by their remarkable ability to improve the pharmacokinetics profile of known neuroprotective agents. As potent lipophilic scaffolds, they can be employed to target the brain delivery of desired compounds. Inflammation is a key mediator of neuronal cell's degeneration as activated microglia and other inflammatory mediators propagate oxidative damage and neuronal loss. Epidemiological and clinical evidence suggests that non-steroidal anti-inflammatory drugs (NSAIDs) slow down the progression and onset of neurodegenerative diseases. The beneficial effects of NSAIDs in ND can be attributed to their ability to inhibit cyclooxygenase enzymes thereby halting the biosynthesis of prostaglandins (PG) which are powerful mediators of inflammation. NSAIDs also inhibit the expression of pro- inflammatory genes. Despite their potential neuroprotective activity, NSAIDs are poorly lipophilic due to the presence of polar carboxylic acid groups and will therefore ionise at physiological pH, deterring them from reaching the desired site of action in the central nervous system (CNS).

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lucia Šinaľová Supervisor: RNDr. Jakub Hofman, Ph.D. Title of diploma thesis: Testing of the cytotoxicity of potential drugs in the cell lines together with the measurement of their passage through the blood brain barrier by the PAMPA method This master thesis focuses on the prediction of tacrine derivatives permeability through blood- brain barrier and their cytotoxicity. We studied tacrine-benzothiazole and tacrine- thiaquinazoline derivates as potential drugs for treatment of Alzheimer's disease. The reason of testing new tacrine derivates was effort to find substances with same effect and lower toxicity, for which was the tacrine discarded from clinical practice. The probable permeability of the studied substances was determined in vitro by the PAMPA method. Based on the permeation coeficient values we have identified that tacrine-benzothiazole derivates A-D (Pe= 8,31- 16,9×10-6 cm/s) and tacrine-thiaquinazoline derivates 1, 3, 4 (Pe= 8,59-14,9×10-6 cm/s) were permeable through blood-brain barrier, tacrine-thiaquinazoline derivate 2 (Pe= 3,79×10-6 cm/s) had uncertain permeability and tacrine-thiaquinazoline derivate 5 (Pe= 2,0×10-6 cm/s) was not permeable. In the pre-clinical evaluation of...

Magister Scientiae - MSc (Medical BioSciences) / Central nervous system (CNS) infections are a therapeutic challenge. This is partly due to insufficient drug penetration across the blood-brain barrier (BBB). The BBB is a specialized, highly selective, metabolically active physiological barrier that regulates the movement of molecules into-and-out of the brain. As a result, large hydrophilic antibiotics such as colistin poorly penetrate to the CNS. Colistin is an old 'last line of defence'; a gram-negative antibiotic that has seen its clinical re-emergence due to the surge of multidrug resistance (MDR) infections. However, owing to systemic toxicity, increasing the intravenous dosage, in order to obtain higher CNS penetration, is inimical. Chitosan (CS) based nanoparticles (NPs) have been proposed as drug delivery systems across the BBB. CS is a cationic, natural polysaccharide that has the ability to be complexed with multivalent polymers like dextran (DS) thus forming CS-DS NPs. Naturally, CS has remarkable inherent features such as biocompatibility, biodegradability, ability to encapsulate poorly soluble drugs and it is favourable for endothelial cell uptake. However, polymeric NPs (even those derived from natural polysaccharides) have limited use due to toxicity. Considering the vital role of the BBB, toxicity would denote dire effects on CNS functioning. Therefore, treatment of CNS infections fringes on a deeper understanding of the interactions between drug delivery systems and the BBB.

Le MSRV (Multiple Sclerosis Associated Retro Virus) fait partie de la famille de rétrovirus endogènes humains HERV-W. Une protéine d'enveloppe provenant du MSRV est retrouvée chez la plupart des patients atteints de sclérose en plaque (SEP). Cette protéine (Env-ms) a des propriétés pro-inflammatoires sur les cellules immunitaires et pourrait donc jouer un rôle dans la pathogenèse de la SEP en exacerbant la diapédèse leucocytaire observée dans le système nerveux central (SNC) des patients. Cette étude vise principalement à analyser les effets de Env-ms sur la barrière hémato-encéphalique (BHE) au niveau moléculaire et fonctionnel. Nous avons pu démontrer que l'enveloppe recombinante du MSRV était capable de stimuler plusieurs paramètres inflammatoires sur un modèle humain de BHE in vitro, la lignée HCMEC/D3. En effet, Env-ms induit une surexpression d'ICAM-1, une protéine impliquée dans l'adhésion des leucocytes aux cellules endothéliales, d'une manière dose dépendante ainsi qu'une production dose dépendante de cytokines pro-inflammatoires comme l'IL-6 et l'IL-8. De plus, par une approche utilisant des siRNAs, nous avons pu montrer que Env-ms était reconnue par le récepteur TLR4, un récepteur de l'immunité innée exprimé par les cellules endothéliales. Nous avons aussi montré par des essais fonctionnels que Env-ms stimulait de manière significative l'adhésion de cellules immunitaires activées à la monocouche de cellules endothéliales. Enfin, nous avons aussi mesuré les effets de Env-ms sur des cultures primaires de cellules endothéliales HUVEC et nous avons pu montrer que les propriétés pro-inflammatoires de la protéine d'enveloppe étaient similaires à celles observées sur le modèle HCMEC/D3 Ces résultats appuient l'hypothèse selon laquelle le MSRV pourrait être impliqué dans la pathogenèse de la SEP ou bien dans le maintien d'un niveau d'inflammation élevé favorisant le désordre immunitaire observé chez les patients. Le MSRV pourrait également jouer un rôle dans d'autres maladies inflammatoires chroniques. / The MSRV (Multiple Sclerosis Associated Retro Virus) belongs to the human endogenous retrovirus HERV-W family. An envelope protein originating from the MSRV was found in most patients with multiple sclerosis (MS). This protein (Env-ms) has pro-inflammatory properties on several immune cells and could therefore play a role in the MS pathogenesis by promoting the leukocyte diapedesis observed in the central nervous system of patients. Our study aims to analyze the effects of Env-ms on the blood-brain barrier (BBB) at a molecular and functional level. We have demonstrated that the recombinant MSRV envelope was able to strongly stimulate several inflammatory parameters on a human BBB in vitro model, the HCMEC/D3 cell line. Indeed, Env-ms induced overexpression of ICAM-1, a major mediator of leukocyte adhesion to endothelial cells, in a dose-dependent manner and a strong dose-dependent production of the pro-inflammatory cytokines IL-6 and IL-8. Furthermore, using a silencing approach with siRNAs, we have shown that Env-ms was recognized via the TLR4 receptor, a pattern recognition receptor of innate immunity present on endothelial cells. Indeed, the knock down of TLR4 abolishes the pro-inflammatory effects of Env-ms. We have also shown using functionnal assays, that the treatment of brain endothelial cells with Env-ms significantly stimulated the adhesion of activated immune cells to the monolayer of endothelial cells. We also assessed the effects of Env-ms on primary endothelial cells HUVECs and we observed that the pro-inflammatory properties of the envelope protein were similar to those observed on HCMEC/D3. These findings support the hypothesis that MSRV could be involved in the pathogenesis of MS disease or at least in maintenance of inflammatory conditions thus fueling the auto-immune disorder. The MSRV could also play a role in other chronic inflammatory diseases.

Made available in DSpace on 2014-10-09T12:43:02Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:39Z (GMT). No. of bitstreams: 1 06211.pdf: 4280505 bytes, checksum: f590901934d469233907b4a44c9ef5ee (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

A sonotrombólise pela combinação de ultrassom (US) e microbolhas com medicamento trombolítico tem indicado grande eficácia na quebra de coágulos in vitro, devido a efeitos de cavitação. Contudo, estudos in vivo sobre drug delivery demonstram que a cavitação de microbolhas é também capaz de abrir local e transientemente a barreira hematoencefálica (BHE) - estrutura de permeabilidade seletiva que protege o Sistema Nervoso Central. Um estudo clínico sobre sonotrombólise foi interrompido precocemente devido a evolução de casos de Acidente Vascular Cerebral isquêmicos para hemorrágicos associados a danos na BHE e formação de ondas estacionárias. Nesta tese, foram realizados estudos in vitro e in vivo sobre técnicas de US multifrequencial para trombólise. Além disso, verificou-se os limiares para a abertura da BHE e efeitos de neuromodulação ambos causados pelo ultrassom transcraniano. Foi demonstrado que o duplo feixe de US e a variação temporal de frequências (excitação codificada) são capazes de reduzir a formação de ondas estacionárias e gerar regiões focais mais confinadas do que feixes focalizados monofrequenciais. O duplo feixe foi incapaz de gerar ondas de baixa frequência para trombólise (menor ou igual a 1 Pa para feixes primários de 1,58 MPa). Exames histológicos e por imagens de ressonância magnética mostraram que a cavitação de microbolhas pode causar danos ao tecido cerebral para níveis de pressão de mesma ordem necessários para se observar efeito trombolítico. Além disso, foi observado que o US é capaz de disparar atividade neuronal causando respostas motoras e indícios de respostas associadas a modulação de atividades cognitivas. A focalização de feixes por excitação multifrequencial é um grande avanço para sonotrombólise. Contudo, a potencialização do efeito trombolítico do US por cavitação e medicamento é limitada devido a danos a BHE e critérios de exclusão do medicamento. / Sonothrombolysis by combining ultrasound (US) and microbubbles with thrombolytic drugs has been demonstrated capable of breaking blood clots in in vitro studies, due to cavitation effects. However, in vivo drug delivery studies have demonstrated that cavitation of microbubbles is also capable of opening locally and transiently the blood-brain barrier (BBB) - structure with selective permeability that protects the Central Nervous System. A sonothrombolysis clinical study was interrupted prematurely because of the occurrence of intracerebral hemorrhages after treatment associated with damages in the BBB and standing waves formation. In this dissertation, in vitro and in vivo studies evaluated techniques of multifrequency US for thrombolysis. Furthermore, the ultrasound pressure threshold to obtain the BBB opening and neuromodulation effects were explored during transcranial insonation. It has been demonstrated that the double US beam and the time variation of frequencies (coded excitation) are capable of reducing standing wave formation and generating more confined focus zones than monofrequency focused beams. The double US beam was not capable of generating low frequency waves for thrombolysis (less than or equal to 1 Pa obtained from primary beams with 1.58 MPa). Histological exams and magnetic resonance images demonstrated that microbubbles cavitation can damage the brain tissue with acoustic pressures of the same level necessary to observe thrombolytic effects. Furthermore, it was observed motor responses and other responses associated with cognitive activity triggered by US. The capability of multifrequency excitation in focusing US beams is an important advance for sonothrombolysis. However, the enhancement of fibrinolytic effect of US by microbubbles cavitation and with thrombolytic drugs is limited by associated damages to the BBB and by exclusion criteria for the use of the thrombolytic drugs.

Orientador: Maria Alice da Cruz-Hofling / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T03:10:26Z (GMT). No. of bitstreams: 1 Carneiro_CatarinaRaposoDias_M.pdf: 5524356 bytes, checksum: 004e2cd5a35766528eaa3a890eef3854 (MD5) Previous issue date: 2006 / Resumo: Recentemente foi demonstrado em nosso laboratório que o veneno bruto da aranha Phoneutria nigriventer (PNV), Keyserling (1891) (Ctenidae, Araneomorphae), é capaz de alterar a permeabilidade da barreira hematoencefálica (BHE), quando injetado sistemicamente em ratos (observações feitas das 18 horas aos 9 dias). Afora a presença de edema vasogênico e de pés astrocitários edematosos, não foram detectadas alterações nos neurônios e células gliais, que indicassem a ação do veneno no interior do parênquima cerebral. O presente trabalho se propôs a avaliar se, em fases agudas do envenenamento, o PNV afeta a BHE e o tecido neural. Os parâmetros observados por microscopia eletrônica de transmissão (através do uso de traçador extracelular injetado na circulação e estudo quantitativo) e microscopia de luz (imunohistoquímica e estudo quantitativo) foram: alterações de permeabilidade vascular na microcirculação cerebral, alterações na expressão da laminina na membrana basal endotelial, ativação neuronal através da expressão da proteína c-FOS, modulação da síntese de óxido nítrico, através da expressão da óxido nítrico sintase neuronal (nNOS). Ratos Wistar machos, jovens (200-300 g) foram injetados pela veia da caudal com solução salina estéril (0.9%), ou com veneno (850 µg/Kg). Para análise da integridade da BHE, após 15 min, 1, 2 e 5 h, cerebelo e hipocampo foram coletados. Os resultados mostraram que o PNV provocou extravasamento significativo do traçador nitrato de lantano a partir de 1 h após a injeção (p.i.) e teve o seu maior pico em 2 h p.i. (p< 0,05). O cerebelo mostrou-se bem mais resistente ao aumento de permeabilidade vascular do que o hipocampo. Por outro lado, freqüentemente observou-se entumecimento dos pés-vasculares astrocitários no cerebelo, mesmo em vasos sem extravazamento do traçador, o que não ocorreu no hipocampo. Houve desaparecimento total da expressão da laminina dos capilares já aos 15 min p.i., seguida por recuperação gradativa, até que às 2 h p.i., sua expressão assemelha-se à mostrada pelos controles e 5 h p.i., a expressão dessa proteína estava acima da fisiológica, na membrana basal. A ativação de neurônios, avaliada às 2 h p.i. pela expressão da c-FOS, ocorreu em áreas relacionadas com atividade motora (substância cinzenta periaqueductal ¿ partes ventral e dorso lateral, córtex frontal e parietal e núcleo talâmico periventricular) e em áreas envolvidas com stress agudo (córtex rinal e núcleo septal lateral) (p< 0,05). Todas as áreas com significativo aumento de neurônios imunoreativos, também apresentaram neurônios positivos para nNOS, porém apenas a substância cinzenta periaqueductal parte dorsolateral, o córtex parietal e o núcleo talâmico periventricular apresentaram aumento no número de neurônios marcados para essa enzima. Nós concluímos que o veneno de P. nigriventer possui componentes neurotóxicos capazes de alterar a permeabilidade da BHE em tempos agudos após a intoxicação, cujo mecanismo precisa ser esclarecido. O veneno pode ser uma ferramenta importante para analisar as respostas dos componentes estruturais da BHE, bem como mapear as áreas cerebrais reativas, possibilitando esclarecer as vias do SNC envolvidas no envenenamento por Phoneutria. O conhecimento de vias relacionadas com neurotoxinas específicas do veneno pode ser útil para estudos relacionados com estrutura-função / Abstract: It was recently demonstrated in our laboratory that the Phoneutria nigriventer spider venom (PNV), Keyserling (1891) (Ctenidae, Araneomorphae), is capable of altering the permeability of the blood brain barrier (BBB) when injected systemically in rats (observations done from 18 hours to 9 days). Apart from the presence of vasogenic edema and swollen atrocytic end-feet processes, no neuronal or glial cells alterations were detected, which would indicate the action of the venom within the cerebral parenchyma.The present work, intended to evaluate if at acute phases of the envenoming, the PNV affects the BBB. The parameters observed by transmission electron microscopy (by the use of electron opaque extracellular tracer injected in the circulation, and quantitative study) and by light microscopy (using immunohistochemistry and quantitative study) were: alterations of vascular permeability in the cerebral microcirculation, alterations of the expression of laminin at the endothelial basement membrane, neuronal activation seen through the expression of c-FOS protein, modulation of nitric oxide synthesis, trough the expression of the neuronal nitric oxide synthase (nNOS). Young male Wistar rats (200-300 g) were injected by the tail vein with sterile saline solution (0.9%), or with venom (850 µg/Kg). For BBB integrity analysis, after 15 min, 1, 2 and 5 h, cerebellum and hippocampus were collected. The results showed that the PNV provoked significant extravasation of LaNO3 tracer at 1 h post injection (p.i.) which peaked at 2 h p.i. (p< 0.05). The cerebellum showed to be more resistant to prevent vascular permeability increase than hippocampus. On the other hand, swollen vascular end-feet processes were more frequently seen in the cerebellum, even in vessels without vascular extravasation, what was not seen in hippocampus. There was complete vanishment of laminin immunolabeling of capillaries soon at 15 min p.i., followed by a gradual restoration to control levels at 2 h p.i. At 5 h p.i., the expression of the protein was upregulated in the basement membrane, compared to the physiologic control. The neuronal activation, evaluated through the expression of c-FOS at 2 h p.i., occurred at motor-related areas (periaqueductal gray matter pars ventral and dorsolateral, frontal and parietal cortex and paraventricular thalamic nuclei), and with acute stress-related areas (rhinal cortex and septal lateral nuclei) (p< 0.05). All cerebral areas with significant increase of c-FOS immunoreactive neurons, also exhibited nNOS-positive neurons, however only the pars ventral and dorsolateral of the periaqueductal gray matter, frontal and parietal cortex and paraventricular thalamic nuclei areas presented increase in the labeled-cells number. We conclude that P. nigriventer venom possesses neurotoxic components capable of altering the BBB permeability at acute stages of intoxication, whose mechanism needs clarification. The venom can be an important tool to analyse the responses of structural components of BBB, and to map the reactive cerebral areas, therefore shedding light to pathways involved with Phoneutria envenoming in CNS. The knowledge of the pathways related to specific venom containing neurotoxins may be useful for structure-function-related studies / Mestrado / Histologia / Mestre em Biologia Celular e Estrutural

Made available in DSpace on 2018-06-27T18:56:25Z (GMT). No. of bitstreams: 2 Ricardo Lorenzoni.pdf: 2169381 bytes, checksum: 9b086c1fe18c612a1d43ebe5f91c0f8f (MD5) Ricardo Lorenzoni.pdf.jpg: 3465 bytes, checksum: 60fb1578356f3148589233475ed9e01a (MD5) Previous issue date: 2012-04-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The hypothesis of Alzheimer s Disease (DA) may be related to high serum cholesterol levels made lipid-lowering drugs, as lovastatin (LV) and simvastatin (SV), potential choices of treatment against this disease. However, low levels of simvastatin and lovastatin are able to cross the blood brain barrier (BHE) and side effects associated to these drugs are a problem for their use in diseases affecting the central nervous system (SNC). Therefore, considering the therapeutic potentials of nanocapsules, the aim of this work was develop, characterize and evaluate the biological effect of NC containing SV or LV in animal models of DA induced by hypercholesterolemia. NC polymeric suspensions were prepared with SV (NCSV) or LV (NCLV) by interfacial deposition of preformed polymers. NCLV and NCSV exhibited average particle size of 204.0 ± 1.5 nm and 205.5 ± 0.5 nm, respectively, as monodispersed systems, with slightly acid pH (around 6) and negative zata potential (-23.29 ± 0.80 for NCLV and -19.5 ± 0.13 mV for NCSV). The analysis by fourier transform infrared spectroscopy and differential canning calorimetry (DSC) indicated that no chemical reactions occurred among components during nanocapsule preparation. The DSC analysis showed that sorbitan monostearate was dissolved in the oil core. The X-ray diffractometry, scanning electron microscopy (SEM), optical microscopy and drug content showed that a large amount lovastatine was presented in a crystalline form in NCLV, and they were not encapsulated. On the other hand, for NCSV, simvastatin was amorphous, indicating absent of drug crystals and that the drug was molecularly dispersed in NC. The encapsulation efficacy of LV was low (21.52 ± 1.4 %) while of SV was very high (99.18 ± 0.7 %). The animals fed with hyperlipemic diet showed significantly increase of serum cholesterol levels and LDL-cholesterol, however the treatment with unencapsulated SV and nanocapsules loading SV 1 mg/kg/dia and 3 mg/kg/day, during 45 days, not sufficient for reducing these biochemistry parameters. The serum triglycerides and VLDL-cholesterol levels did not show significant variations. The HDL-cholesterol was higher for animals treated with free SV (3mg/kg/day). The animals fed with hyperlipemic diet and/or treated with free drug or loaded in nanocapsules didi not show any increase of liver transaminases, indicating that there was no liver damage. The activity of pyruvate kinase and creatine kinase suggested that there were not any changes in neuronal energy metabolism. The hypercholesterolemia was capable of inducing alterations in cognition in Wistar rats. The NCSV showed promising effects in DA, once the animals were able to enhance memory when subjected to passive avoidance test. Free SV led to no significant alterations in learning and memory. The histology results suggested the presence of some brain lesions in some groups, indicating a possible neurodegeneration. Based on these results, we can conclude that simvastatin nanocapsules are a promising alternative in the treatment of cognitive loss due to high cholesterol levels and deserves more studies. / A hipótese de que o desenvolvimento da Doença de Alzheimer (DA) pode estar relacionado com altos níveis de colesterol plasmático faz dos fármacos hipolipemiantes, como Lovastatina (LV) e Sinvastatina (SV), potenciais terapêuticos frente a esta enfermidade. Contudo, a baixa penetração da LV e da SV através da barreira hematoencefálica (BHE) e os efeitos colaterais que elas podem ocasionar apresentam-se como um impasse para a utilização destes fármacos frente a doenças que acometem o sistema nervoso central. Deste modo, considerando as potencialidades terapêuticas que as nanocápsulas poliméricas (NC) podem promover, este trabalho teve como objetivo, desenvolver, caracterizar e avaliar o efeito biológico de NC contendo SV ou LV frente ao modelo animal da DA induzida por hipercolesterolemia. Assim, foram desenvolvidas suspensões de NC poliméricas contendo SV (NCSV) ou LV (NCLV) através do método de deposição interfacial do polímero pré-formado. As suspensões exibiram tamanho médio de partícula homogêneo (204,0 ± 1,5 nm para as NCLV e 205,5 ± 0,5 nm para as NCSV), com baixo índice de polidispersão, caracterizando sistema monodispersos, com pH levemente ácido (em torno de 6) e potencial zeta negativo (-23,29 ± 0,80 mV para as NCLV e -19,5 ± 0,13 mV para as NCSV). As análises de espectroscopia na região do infravermelho com transformada de Fourier e calorimetria exploratória diferencial (DSC) indicaram que não houve reação química entre os componentes da formulação durante a produção das formulações. A avaliação por DSC mostrou que o monoestearato de sorbitano encontra-se dissolvido no núcleo oleoso das partículas. A difração de raios-X, a microscopia eletrônica de varredura (MEV), microscopia óptica revelaram que grande quantidade de fármaco apresentou-se sob a forma cristalina nas suspensões de NCLV. Por outro lado, a difração de raios-X, MEV e microscopia óptica revelaram que a SV encontra-se molecularmente dispersa nas suspensões de NCSV. Assim, a eficiência de encapsulação da LV foi baixa (21,52 ± 1,4 %) enquanto que para a SV foi alta (99,18 ± 0,7 %). Os animais alimentados com dieta hiperlipídica apresentaram aumento significativo do colesterol total e do LDL-colesterol, porém os tratamentos com SV livre e nanoencapsulada nas doses de 1 mg/kg/dia e 3 mg/kg/dia, durante 45 dias, não foram suficientes para reduzir estes parâmetros bioquímicos. Os triglicerídeos séricos e VLDL-colesterol não apresentaram variações significativas induzidas pela dieta ou como consequência do tratamento medicamentoso. O HDL-colesterol apresentou-se mais elevado apenas para os animais tratados com SV livre. Não houveram evidências de aumento das aminotransferases séricas, sugerindo ausência de dano hepático. As atividades da piruvatoquinase e da creatinoquinase indicaram que não houve alteração no metabolismo energético neuronal. A hipercolesterolemia foi capaz de induzir alterações cognitivas em ratos. A SV nanoencapsulada apresentou efeitos promissores frente à cognição, pois foram capazes de melhorar a memória dos animais submetidos ao teste de esquiva passiva. A SV livre não provocou alterações significativas no aprendizado e na memória dos animais neste teste. Os resultados histopatológicos indicam que houveram lesões cerebrais em alguns grupos de animais, indicando um possível efeito de neurodegeneração. Com base nos resultados, podemos concluir que as nanocápsulas de sinvastina são uma alternativa de uso terapêutico promissora e que merece mais estudos nos casos de perdas cognitivas por excesso de colesterol plasmático.

Made available in DSpace on 2014-10-09T12:43:02Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:39Z (GMT). No. of bitstreams: 1 06211.pdf: 4280505 bytes, checksum: f590901934d469233907b4a44c9ef5ee (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP