Lipids are important for the structural and physiological functions of neuronal cell membranes. Alterations in their lipid composition may result in membrane dysfunction and subsequent neuronal deficits that characterise various disorders. This study focused on profiling lipids of aged and LPS-treated rat brain and liver tissue with a view to explore the effect of atorvastatin in neuroinflammation, and examining lipid changes in different areas of rat brain of the Flinders Sensitive Line (FSL) rats, a genetic model of depression. Lipids and other analytes extracted from tissue samples were analysed with proton nuclear magnetic resonance spectroscopy (1H-NMR), gas chromatography (GC) and liquid chromatography-tandem mass spectroscopy (LC/ESI-MS/MS). Changes in the lipid profiles suggested that brain and liver responded differently to ageing and LPS-induced neuroinflammation. In the aged animals, n-3 PUFA were reduced in the brain but were increased in the liver. However, following treatment with LPS, these effects were not observed. Nevertheless, in both models, brain concentration of monounsaturated fatty acids was increased while the liver was able to maintain its monounsaturated fatty acid concentration. Atorvastatin reversed the reduction in n-3 PUFA in the aged brain without reducing brain and liver concentration of cholesterol. These findings further highlight alterations in lipid metabolism in agerelated neuroinflammation and show that the anti-inflammatory actions of atorvastatin may include a modulation of fatty acid metabolism. When studying the FSL model, there were differences in the lipid profile of different brain areas of FSL rats compared to Sprague-Dawley controls. In all brain areas, arachidonic acid was increased in the FSL rats. Docosahexaenoic acid and ether lipids were reduced, while cholesterol and sphingolipids were increased in the hypothalamus of the FSL rats. Furthermore, total diacylglycerophospholipids were reduced in the prefrontal cortex and hypothalamus of the FSL rats. These results show differences in the lipid metabolism of the FSL rat brain and may be suggestive of changes occurring in the brain tissue in depression.

This study demonstrates original findings of statin effects on IL-33 stimulated mast cells. Statins are a class of drugs used to lower cholesterol production by targeting HMG CoA reductase. These commonly prescribed drugs have been shown to be immunomodulatory. In this study, we have found that pretreatment with statins has a variety of effects on IL-33 stimulated mast cells. Atorvastatin suppresses TNF and IL-6 production, while fluvastatin significantly enhances release of these proinflammatory cytokines in BMMCs. Although they have differing effects on cytokine production, both statins lowered ST2 expression on the cell surface, decreased cell viability, and enhanced expression of the transcription factor KLF2, a negative regulator of NFκB. Blocking isoprenylation by using geranylgeranyl transferase inhibitor, but not farnesyl transferase, mimicked the effects of atorvastatin, while neither mirrored the effect of fluvastatin. Furthermore, fluvastatin effects were not reversed by mevalonic acid, the product of HMG-CoA reductase. These data indicate that fluvastatin effects are distinct from its activities as an HMG CoA reductase inhibitor. Fluvastatin effects required the presence of stem cell factor (SCF), and were enhanced by increasing SCF concentrations. Finally, fluvastatin enhanced IL-33-induced cytokine production and neutrophil recruitment in vivo. Collectively, these data suggest that statins can alter the mast cell response, and that drug choice can have divergent effects on outcome.

A ATP-binding cassette transporter A1 (ABCA1) é uma proteína transmembrana responsável pelo efluxo celular de colesterol e fosfolipídeos, que é um passo essencial para o transporte reverso do colesterol e para a biogênese da HDL. Polimorfismos do gene ABCA1 foram associados com risco de doença arterial coronariana, variações no perfil lipídico e diferenças na resposta a fármacos hipolipemiantes. Com a finalidade de avaliar os efeitos de polimorfismos do ABCA1 sobre a expressão gênica e a resposta a vastatinas, foram selecionados indivíduos normolipidemicos (NL, n=143) e hipercolesterolêmicos (HC, n=224). A resposta a atorvastatina (10 mg/dia/4 semanas) foi avaliada pelo perfil lipídico sérico em 141 indivíduos do grupo HC (ATORVA). DNA e RNA total foram extraídos de amostras de sangue periférico. Os polimorfismos de nucleotídeo único (SNP) G70943A (R219K), C-14T e C-105T, uma variante nova do ABCA1, foram detectados por PCR-RFLP e confirmados por seqüenciamento de DNA. A expressão de RNAm do ABCA1 em células mononucleares do sangue periférico (CMSP) foi analisada por PCR-duplex e PCR em tempo real, utilizando o gene GAPD como referência endógena. A freqüência do alelo -105T foi 1,4% em NL e 2,0% em HC. O alelo 70943A (genótipos GA+AA) foi associado com maior concentração sérica basal de apoAI (NL), de HDL-c (ATORVA) e com menores concentrações basais de triglicerídeos e VLDL-c e menor índice TG/HDL-c (HC e ATORVA) em comparação com o genótipo 70943GG (p<0,05). O polimorfismo C-105T está em desequilíbrio de ligação com o SNP C-14T (p=0,006). Portadores do alelo -105T (genótipos CT+TT), quando comparados aos portadores do genótipo -105CC, tiveram menores valores basais de triglicerídeos e VLDL-c, maior concentração de HDL-c e menor índice TG/HDL-c nos grupos HC e ATORVA e também maiores concentrações de apoAI e menor índice apoB/apoAI no grupo ATORVA (p<0,05). Nos grupos HC e ATORVA, os portadores do haplótipo -14CT+TT/-105CT+TT tiveram menores valores de triglicerídeos e VLDL-c basais, maiores concentrações de HDL-c e menor índice TG/HDL-c quando comparados aos portadores dos outros haplótipos (p<0,05). A expressão basal do ABCA1 foi menor nos HC que nos NL independentemente da taxa de expressão alta (GM1) ou baixa (GM2). Este efeito foi associado com os SNPs C-14T e G70943A SNPs. Após o tratamento com atorvastatina, a expressão de RNAm foi reduzida nos HC portadores do alelo - 14T em comparação com os portadores de alelo -14C. Esses resultados são sugestivos de que ABCA1 SNPs estão envolvidos na variação do perfil lipídico sérico e na expressão de RNAm em resposta a atorvastatina. / The ATP-binding cassette transporter A1 (ABCA1) is a transmembrane protein involved on cholesterol and phospholipid cellular efflux, which is an essential step for the reverse cholesterol transport and HDL biogenesis. Single nucleotide polymorphisms (SNPs) in the ABCA1 gene have been associated with increased risk of coronary heart disease, differences on serum lipid profile and response to lowering-cholesterol drugs. We have evaluated the influence of ABCA1 SNPs on mRNA expression and lipid-lowering response to atorvastatin. Normolipidemic (NL, n=143) hypercholesterolemic (HC, n=224) individuals were enrolled in this study and the response to atorvastatin (10 mg/day/4 weeks) was evaluated in HC individuals (ATORVA, n=141). Blood samples were collected for biochemical analyses, genomic DNA and total RNA extraction. SNPs G70943A (R219K), C-14T and C-105T, a novel variant of ABCA1, were detected by PCR-RFLP and confirmed for DNA sequencing. ABCA1 mRNA expression in peripheral blood mononuclear cells (PBMC) was analysed by PCR-duplex and Real Time PCR, using the GAPD as the endogenous reference. In HC and NL, the frequency of -105T allele was 2.0% and 1.4%, respectively. The 70943A allele (genotypes GA+AA) was associated with higher basal concentrations of apoAI (NL) and HDL-c (ATORVA) and lower triglyceride and VLDL-c and TG/HDL-c ratio (HC and ATORVA) than the 70943GG genotype (p<0.05). We found a linkage disequilibrium between C-14T and C-105T SNPs in HC group (p=0.006). Individuals carrying -105T allele (CT/TT genotypes), when compared with -105CC carriers, had lower basal concentrations of triglyceride and VLDL-c, higher concentration of HDL-c and lower TG/HDL-c ratio in HC and ATORVA groups and also higher concentration of apoAI and lower apoB/apoAI ratio in ATORVA group (p<0.05). In HC and ATORVA, individuals with -14CT+TT/-105CT+TT haplotype had lower basal values of triglyceride and VLDL-c, higher concentration of HDL-c and lower TG/HDL-c ratio than carries of others haplotypes (p<0,05). ABCA1 mRNA basal expression was lower in HC when compared to NL independently of high (GM1) or low (GM2) basal expression rate. This effect was associated with C-14T and G70943A SNPs. After atorvastatin treatment, mRNA expression was reduced in HC individuals carrying -14T allele in comparison with the -14C allele carriers. These results are sugestive that ABCA1 SNPs are involved on variation of serum lipid profile and mRNA expression in response to atorvastatin.

O objetivo do presente trabalho foi desenvolver e avaliar minicomprimidos obtidos a partir de quatro formas polimórficas de atorvastatina cálcica. Inicialmente foi realizada uma caracterização físico-química das amostras (amorfa e formas cristalinas I, VI e VIII), empregando-se os ensaios de dissolução intrínseca e solubilidade através dos métodos do disco rotacional e do equilíbrio, respectivamente. Na sequência, foi realizada a caracterização do estado sólido por difração de raios-x, DSC (differencial scanning calorimetry) e termogravimetria. Foi observado que o polimorfo VIII demonstrou maior velocidade de dissolução intríseca, seguido pelas formas amorfa, VI e I. Adicionalmente, foram avaliadas as propriedades das partículas de atorvastatina cálcica a fim de verificar sua influência nos resultados de solubilidade e dissolução intrínseca. As seguintes análises foram conduzidas: tamanho e distribuição do tamanho de partícula, densidades (aparente, compactada e verdadeira), microscopia eletrônica de varredura, área superficial, termogravimetria derivada e solubilidade com tensoativo. Os resultados demonstraram diferenças significativas dentre as partículas das amostras avaliadas, principalmente quanto à morfologia e área superficial, as quais podem ter influenciado os resultados de dissolução intrínseca. Finalmente, definiu-se uma formulação de minicomprimidos que foi preparada com as quatro amostras do fármaco através do processo de compressão direta, utilizando-se um punção múltiplo com 3 pontas, de 3 mm cada. As formulações foram avaliadas quanto ao peso médio, dureza, friabilidade, espessura, teor e perfil de dissolução. Os resultados indicaram que as diferentes formas de atorvastatina cálcica são capazes de influenciar o perfil de liberação do fármaco a partir da formulação proposta, reforçando a importância do estudo de pré-formulação no desenvolvimento de formas farmacêuticas sólidas contendo atorvastatina cálcica. / The purpose of this study was to develop and evaluate minitablets obtained from four polymorphic forms of atorvastatin calcium. Initially, the physicochemical characterization of the samples (amorphous and forms I, VI and VIII) was made by applying the intrinsic dissolution rate and solubility studies using the rotation disk and shake-flask methods, respectively. Further, the solid state characterization was made by means of x-ray powder diffraction, differential scanning calorimetry and termogravimetric analysis. It was observed that the polymorph VIII showed the highest intrinsic dissolution rate, followed by the amorphous form, polymorph VI and I. Additionally, the particle properties were evaluated in order to check its influence on the solubility and intrinsic dissolution results previous obtained. The following tests were conducted: size and size distribution of the particles, densities (apparent, compacted and true), scanning electron microscopy, surface area, differential termogravimetric analysis and solubility with surfactant. The results showed significant differences between the particles of the samples, especially in terms of morphology and surface area, which may have influenced the results of the intrinsic dissolution. Finally, a minitablet formulation was defined and prepared with the four samples of the drug by direct compression process, with a multi tip punch with 3 tips of 3 mm each one. The formulations were analyzed regarding their weight, hardness, friability, thickness, assay and dissolution profile. The results suggested that the different forms of atorvastatin calcium are capable of influencing the dissolution profile of the drug from the proposed formulation, reinforcing the importance of the preformulation study in the development of solid dosage forms with atorvastatin calcium.

As estatinas são medicamentos comumente prescritos para a prevenção da hiper-lipidemia. Além da redução do colesterol, tais medicamentos parecem estimular a osteogênese e suprimir a reabsorção óssea, o que poderia afetar a movimentação dentária induzida (MDI) e a recidiva ortodôntica. Assim, o objetivo deste estudo foi determinar se a atorvastatina (ATV) pode afetar a MDI, a recidiva e a osteoclastogênese, por meio da modulação da expressão das moléculas: - ligante do receptor ativador de NFκB (RANKL) e osteoprotegerina (OPG). Ainda foram analisados os potenciais efeitos adversos da ATV sobre a ossificação endocondral e sobre o turnover de ossos longos. No primeiro experimento, 36 ratos foram sujeitos a MDI durante 21 dias, quando o aparelho foi removido. Aos animais, foram administrados, diariamente, ATV ou solução salina (SAL), via gavagem. Após 7, 14 e 21 dias de administração de ATV / SAL, a recidiva dentária foi mensurada, e foram obtidos os cortes histológicos da maxila e fêmur, os quais foram submetidos às seguintes colorações: - H&E – para análise histomorfométrica; - fosfatase acida tartrato resistente (TRAP) – para contagem de osteoclastos e; - imunohistoquímica para RANKL e OPG. A atorvastatina resultou numa inibição da recidiva ortodôntica (p < 0,05), e numa transiente redução do número de osteoclastos (p < 0,05); havendo uma correlação positiva e significativa (p < 0,01) entre o estes dois fatores (número de osteoclastos e a taxa de recidiva). A administração de estatinas também aumentou significativamente a expressão de OPG (p < 0,01), mas não a de RANKL. Além disso, após 21 dias de administração de ATV, a espessura da cartilagem da placa de crescimento e da zona hipertrófica condrocítica foi significativamente aumentada. Já no segundo experimento, 24 ratos começaram a receber diariamente ATV ou solução salina (SAL), via gavagem. Duas semanas mais tarde, a MDI foi iniciada. O deslocamento do dente foi medido após 7, 14 e 21 dias, enquanto que os cortes histológicos da maxila e do fêmur foram obtidos após 14 e 21 dias de MDI; sendo então submetidos às colorações de H&E e TRAP, para avaliação histomorfométrica e contagem de osteoclastos. A administração de atorvastatina gerou um menor movimento dentário (p <0,05) e uma redução transitória do número de osteoclastos (p <0,05). No grupo SAL, após 14 dias de MDI, ocorreu um aumento no número de osteoclastos, assim reduzindo a taxa de volume ósseo, quando comparado com as maxilas controle (sem movimento dentário), deste mesmo grupo. Contudo, tal comportamento não foi observado no grupo ATV. Interessantemente, depois de 35 dias, a atorvastatina não afetou a remodelação óssea nas maxilas controle, nem a ossificação endocondral em fêmures. Logo, guardando as devidas limitações deste estudo pré-clínico, nossos resultados sugerem que a administração sistêmica de atorvastatina é capaz de minimizar a MDI e recidiva ortodôntica. No entanto, os seus efeitos celulares sobre a ossificação endocondral e remodelação óssea durante a MDI e recidiva, parecem ser limitados a um curto período de tempo, o que aparentemente necessita de investigações futuras. Finalmente, nossos resultados lançam luz sobre a superexpressão OPG induzida por estatinas, o que representa um alvo molecular para modular o metabolismo do ósseo e, assim minimizar a recidiva ortodôntica. / Statins are drugs commonly prescribed for prevention of hyper-lipidemia. In addition to the cholesterol-lowering, these medicines seem to enhance osteogenesis and suppress bone resorption, which could affect orthodontic tooth movement (OTM) and relapse. Therefore, the aim of this study was to determine whether atorvastatin (ATV) might affect the orthodontic relapse or tooth movement and osteoclastogenesis, through the modulation of the following molecules: receptor activator of nuclear κ B ligand (RANKL) and; - osteoprotegerin (OPG). Furthermore, we analyzed potential adverse effects of ATV on long bone turnover and endochondral ossification. In the first experiment, 36 rats were subjected to OTM for 21 days, when the appliance was removed. After, the animals were administered daily with ATV (15mg/Kg) or saline (SAL), via gavage (n=18, per group). Up to 7, 14 and 21 days of ATV/SAL administration the tooth relapse was measured while maxillary and femur histologic sections were obtained and prepared to: - H&E staining – used in histomorphometric analysis, tartrate resistant acid phosphatase histochemical staining (TRAP) – used to osteoclasts counting and, immunohistochemistry to RANKL and OPG. Atorvastatin resulted in a decreased tooth relapse (p<0.05), and a transient reduction of osteoclasts number (p<0.05). There was a positive and significant correlation (p<0.01) between these two parameters (osteoclasts number and relapse rate). The statin administration increased significantly the OPG (p<0.01), but not the RANKL expression. Furthermore, after 21 days of ATV administration, the thickness of growth plate cartilage and chondrocytic hypertrophic zone was enhanced. In the second experiment, 24 rats started to be administered daily with ATV or SAL, via gavage. Two weeks later, the OTM started. The tooth displacement was measured after 7, 14, and 21 days, while the maxillary and femur histologic sections were obtained only after 14 and 21 days of OTM. At these times, the sections were prepared to H&E and TRAP, intending to perform the histomorphometric analysis and osteoclasts count. Atorvastatin administration promoted a decreased tooth movement (p<0.05), and a transient reduction of osteoclasts number (p<0.05). In the SAL group, after 14 days of OTM, the increased number of osteoclasts was associated to a reduced bone volume rate, when compared to its control maxillae. However, this trend was not obvious in ATV group. Interestingly, after 35 days, statins did not affect the bone turnover and endochondral ossification. The big picture of our study suggests that systemic administration of statins is able to minimize OTM and relapse. However, its cellular effects on endochondral ossification and bone turnover during OTM or relapse seem to be limited to a short period, apparently requiring further investigations. Finally, our results shed light on OPG overexpression induced by statins, which represents a molecular target modulating maxillary bone metabolism thus inhibiting orthodontic relapse.

A isoenzima citocromo P450 3A5 (CYP3A5) tem um papel importante na biotransformação de compostos endógenos e xenobióticos. Polimorfismos de nucleotídeo único (SNPs) do gene CYP3A5 foram associados com variações na expressão gênica e atividade enzimática que podem modificar o metabolismo de vários fármacos. Com a finalidade de investigar a influência de SNPs do CYP3A5 sobre a expressão de RNAm e a resposta a atorvastatina, foram selecionados 99 indivíduos normolipidêmicos (NL) e 139 hipercolesterolêmicos (HC). Os pacientes HC foram tratados com atorvastatina (10 mg/dia/4 semanas). Amostras de sangue periférico foram coletadas antes e após o tratamento para análise do perfil lipídico sérico, e extração de DNA genômico e RNA total. Os SNPs CYP3A5*3C e CYP3A5*6 foram analisados por PCR-RFLP e o CYP3A5*1D por sequenciamento de DNA. A expressão de RNAm do CYP3A5 em células mononucleares do sangue periférico (CMSP) foi analisada por PCR em tempo real. No grupo HC, os alelos CYP3A5*3C e CYP3A5*1D foram mais frequentes em brancos (*3C: 84,9% e *1D 84,8%) que em afro-descendentes (*3C: 47,8% e *1D: 55,2%, p<0,01). Os alelos *3C e *1D estavam em desequilíbrio de ligação. A frequência do alelo CYP3A5*6 foi maior em negros (6,8%) que em brancos (0,6%, p=0,002). Não houve associação entre os SNPs do CYP3A5 e o perfil lipídico basal nos grupos NL e HC. Os HC brancos portadores do haplótipo CYP3A5*3A/*3A (alelos *3C e *1D combinados) apresentaram menor redução de colesterol total e LDL-c após o tratamento com atorvastatina do que os portadores dos haplótipos não-CYP3A5*3A/*3A (p<0,05). A expressão de RNAm de CYP3A5 em CMSP aumentou em resposta a atorvastatina (p<0,05) somente nos portadores de haplótipo CYP3A5*3A/*3A. Esses resultados são sugestivos de que os SNPs CYP3A5*3C e CYP3A5*1D são associados com a expressão gênica do CYP3A5 e a resposta de redução de colesterol a atorvastatina. / The cytochrome P450 isoenzyme 3A5 (CYP3A5) has an important role on biotransformation of endogenous compounds and xenobiotics. Single nucleotide polymorphisms (SNPs) of the CYP3A5 gene have been associated with variations on gene expression and enzyme activity that can modify the metabolism of several drugs. In order to evaluate the influence of CYP3A5 SNPs on RNAm expression and response to atorvastatin, 99 mormolipidemic (NL) and 139 hypercholesterolemic (HC) individuals have been enrolled in this study. HC patients were treated with atorvastatin (10 mg/day/four weeks). Blood samples were collected before and after treatment for serum lipids analyses, genomic DNA and total RNA extraction. CYP3A5*3C, and CYP3A5*6 SNPs were analyzed by PCR-RFLP. CYP3A5*1D was analyzed by direct sequencing. CYP3A5 RNAm expression in peripheral blood mononuclear cells (PBMC) was evaluated by Real Time PCR. In HC group, the frequencies of CYP3A5*3C and CYP3A5*1D alleles were higher in white individuals (*3C: 84.9% and *1D 84.8%) that in blacks (*3C: 47.8% and *1D: 55.2%, p<0.01). CYP3A5*3C and *1D alleles were in linkage desequilibrium. CYP3A5*6 allelle frequency was higher in blacks (6.8%) that in white individuals (0.6%, p=0.002). There was no association between CYP3A5 SNPs and baseline lipid profile in NL and HC groups. White HC carriers of CYP3A5*3A/*3A haplotype (*3C and *1D combined alleles) have lower total cholesterol and LDL-c response to atorvastatin than non-CYP3A5*3A/*3A carriers (p<0.05). CYP3A5 RNAm expression on PBMC increased in response to atorvastatin (p<0.05) only in CYP3A5*3A/*3A haplotype carriers. These results are suggestive that CYP3A5*3C and CYP3A5*1D SNPs are associated with CYP3A5 gene expression and cholesterol-lowering response to atorvastatin.

O objetivo do presente trabalho foi desenvolver e avaliar minicomprimidos obtidos a partir de quatro formas polimórficas de atorvastatina cálcica. Inicialmente foi realizada uma caracterização físico-química das amostras (amorfa e formas cristalinas I, VI e VIII), empregando-se os ensaios de dissolução intrínseca e solubilidade através dos métodos do disco rotacional e do equilíbrio, respectivamente. Na sequência, foi realizada a caracterização do estado sólido por difração de raios-x, DSC (differencial scanning calorimetry) e termogravimetria. Foi observado que o polimorfo VIII demonstrou maior velocidade de dissolução intríseca, seguido pelas formas amorfa, VI e I. Adicionalmente, foram avaliadas as propriedades das partículas de atorvastatina cálcica a fim de verificar sua influência nos resultados de solubilidade e dissolução intrínseca. As seguintes análises foram conduzidas: tamanho e distribuição do tamanho de partícula, densidades (aparente, compactada e verdadeira), microscopia eletrônica de varredura, área superficial, termogravimetria derivada e solubilidade com tensoativo. Os resultados demonstraram diferenças significativas dentre as partículas das amostras avaliadas, principalmente quanto à morfologia e área superficial, as quais podem ter influenciado os resultados de dissolução intrínseca. Finalmente, definiu-se uma formulação de minicomprimidos que foi preparada com as quatro amostras do fármaco através do processo de compressão direta, utilizando-se um punção múltiplo com 3 pontas, de 3 mm cada. As formulações foram avaliadas quanto ao peso médio, dureza, friabilidade, espessura, teor e perfil de dissolução. Os resultados indicaram que as diferentes formas de atorvastatina cálcica são capazes de influenciar o perfil de liberação do fármaco a partir da formulação proposta, reforçando a importância do estudo de pré-formulação no desenvolvimento de formas farmacêuticas sólidas contendo atorvastatina cálcica. / The purpose of this study was to develop and evaluate minitablets obtained from four polymorphic forms of atorvastatin calcium. Initially, the physicochemical characterization of the samples (amorphous and forms I, VI and VIII) was made by applying the intrinsic dissolution rate and solubility studies using the rotation disk and shake-flask methods, respectively. Further, the solid state characterization was made by means of x-ray powder diffraction, differential scanning calorimetry and termogravimetric analysis. It was observed that the polymorph VIII showed the highest intrinsic dissolution rate, followed by the amorphous form, polymorph VI and I. Additionally, the particle properties were evaluated in order to check its influence on the solubility and intrinsic dissolution results previous obtained. The following tests were conducted: size and size distribution of the particles, densities (apparent, compacted and true), scanning electron microscopy, surface area, differential termogravimetric analysis and solubility with surfactant. The results showed significant differences between the particles of the samples, especially in terms of morphology and surface area, which may have influenced the results of the intrinsic dissolution. Finally, a minitablet formulation was defined and prepared with the four samples of the drug by direct compression process, with a multi tip punch with 3 tips of 3 mm each one. The formulations were analyzed regarding their weight, hardness, friability, thickness, assay and dissolution profile. The results suggested that the different forms of atorvastatin calcium are capable of influencing the dissolution profile of the drug from the proposed formulation, reinforcing the importance of the preformulation study in the development of solid dosage forms with atorvastatin calcium.

Cerebral ischemia occurs when blood flow to the brain is insufficient to meet metabolic demand. This can result from cerebral artery occlusion that interrupts blood flow, limits CNS supply of oxygen and glucose, and causes an infarction/ischemic stroke. Ischemia initiates a cascade of molecular events in neurons and cerebrovascular endothelial cells including energy depletion, dissipation of ion gradients, calcium overload, excitotoxicity, oxidative stress, and accumulation of ions and fluid. Blood-brain barrier (BBB) disruption is associated with cerebral ischemia and leads to vasogenic edema, a primary cause of stroke-associated mortality. To date, only a single drug has received US Food and Drug Administration (FDA) approval for treatment of acute ischemia/reperfusion injury, recombinant tissue plasminogen activator (rt-PA). While rt-PA therapy restores perfusion to ischemic brain, considerable tissue damage occurs when cerebral blood flow is re-established. Therefore, there is a critical need for novel therapeutic approaches that can "rescue" salvageable brain tissue and/or protect BBB integrity during cerebral hypoxia and subsequent reoxygenation stress (H/R). One approach that may enable neural tissue rescue following H/R is CNS delivery of drugs with brain protective effects such as HMG-CoA reductase inhibitors (i.e., statins). Our present in vivo data demonstrates that atorvastatin, a commonly prescribed statin, attenuates poly (ADP-ribose) polymerase (PARP) cleavage in the brain following H/R, suggesting neuroprotective efficacy. However, atorvastatin use as a CNS therapeutic is limited by poor blood-brain barrier (BBB) penetration. Therefore, we examined regulation and functional expression of the known statin transporter Oatp1a4 at the BBB under H/R conditions. In rat brain microvessels H/R (6% O₂, 60 min followed by 21% O₂, 10 min) increased Oatp1a4 expression. Brain uptake of taurocholate (i.e., Oap1a4 probe substrate) and atorvastatin were reduced by Oatp inhibitors (i.e., estrone-3-sulfate, fexofenadine), suggesting involvement of Oatp1a4 in brain drug delivery. Pharmacological inhibition of TGF-β/ALK5 signaling with the selective inhibitor SB431542 increased Oatp1a4 functional expression, suggesting a role for TGF-β/ALK5 signaling in Oatp1a4 regulation. Taken together, our novel data show that targeting an endogenous BBB drug uptake transporter (i.e., Oatp1a4) may be a viable approach for optimizing CNS drug delivery for treatment of diseases with an H/R component.

Zugl.: Dresden, Techn. Univ., Habil.-Schr., 2008

Introdução: Embora estatinas sejam benéficas após o infarto agudo do miocárdio (IAM), pouco se sabe sobre seus efeitos quando usadas previamente ao evento. Objetivo: Avaliar o efeito do uso prévio de atorvastatina sobre a função cardiovascular, inflamação e GLUT4 no coração de ratos após IAM (oclusão artéria coronária). Métodos: Ratos Wistar-Kyoto, machos, foram tratados com atorvastatina (20mg/kg) ou veículo (gavagem), 14 dias antes do IAM ou cirurgia sham e avaliação ecocardiográfica 48h pós-IAM (Protocolo A) ou + 7 dias de atorvastatina após IAM e avaliação ecocardiográfica 7 dias pós-IAM (Protocolo B), divididos 16/grupo: C (sham+veículo), I (IAM+veículo), CAt (sham+atorvastatina) e IAt (IAM+atorvastatina). Foram avaliados parâmetros funcionais ecocardiográficos, marcadores inflamatórios plasmáticos e GLUT4 no coração (Western blot). Resultados: A área de infarto foi ~50% nos grupos I e IAt. No protocolo A, a fração de encurtamento foi ~60% maior no grupo IAt vs. I (C:50,9±3,9; CAt:47,9±4,0; I:20,7±3,4; IAt:33,4±3,5 %; p=0,036), o que não ocorreu no protocolo B. A fração de ejeção apresentou redução nos animais após IAM (Protocolo A: ~37%; B: ~30%) e a atorvastatina não melhorou este índice. Houve aumento de GLUT4 (miocárdio, membrana plasmática) pelo IAM 48h pós-IAM: C:35,7±6,0; CAt:32,2±10,9; I:49,8±9,8; IAt:54,1±6,3 UA/g tecido; p<0,001, sem benefício pela atorvastatina, e redução 7 dias pós-IAM: C:50,2±4,4; CAt:52,3±3,1; I:39,0±7,9; IAt:26,4±11,0 UA/g tecido; p<0,001, com prejuízo pela atorvastatina (redução de 32% na membrana plasmática). O IAM determinou aumento de marcadores inflamatórios no plasma, não revertido pelo uso de atorvastatina. Conclusão: Atorvastatina prévia ao IAM melhora a contratilidade no miocárdio precocemente independente do GLUT4 cardíaco, efeito que não foi mantido quando da avaliação mais tardia. / Background: Although statins are beneficial after acute myocardial infarction (AMI), its effects when used prior to this event remains unclear. Aim: To evaluate the effect of prior use of atorvastatin on cardiovascular function, inflammatory state and GLUT4 expression in the rat heart after myocardial infarction (coronary artery occlusion). Methods: Wistar-Kyoto male rats were treated with atorvastatin (20mg/kg) or vehicle (gavage), 14 days before the AMI or sham surgery, and echocardiographic evaluation 48 hours after AMI (protocol A) or atorvastatin + 7 days after AMI and echocardiography 7 days after AMI (Protocol B), allocated 16/grupo: C (sham + vehicle), I (AMI + vehicle), CAt (sham + atorvastatin) and IAt (AMI + atorvastatin). Functional echocardiographic parameters, plasma inflammatory markers and GLUT4 in the heart (Western blot) were measured. Results: Infarcted area was ~50% in groups I and IAt. In protocol A, left ventricular fractional shortening was ~60% higher in the IAt vs. I (C: 50.9 ± 3.9; CAt: 47.9 ± 4.0; I: 20.7 ± 3.4; IAt: 33.4 ± 3.5%, p=0.036), which not occur in protocol B. Ejection fraction was reduced in the animals after acute myocardial infarction (Protocol A: ~37%, B: ~30%) and atorvastatin did not improve this parameter. There was an increase of GLUT4 (plasma membrane) in the Protocol A (C: 35.7 ± 6.0; CAt: 32.2 ± 10.9, I: 49.8 ± 9.8; IAt: 54.1 ± 6.3 AU/g tissue, p<0.001) with no benefit by atorvastatin, and reduction in the Protocolo B (C: 50.2 ± 4.4; CAt: 52.3 ± 3.1; I: 39, 0 ± 7.9; IAt: 26.4 ± 11.0 AU/g tissue, p<0.001), damage by atorvastatin (32% reduction in the plasma membrane). The AMI resulted in an increase of inflammatory markers in plasma, not reversed by the use of atorvastatin. Conclusion: Atorvastatin prior to AMI improves myocardial contractility in early heart independent of GLUT4, an effect that was not maintained when evaluating later.