931 resultados para antiviral drugs
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[Ru-2(dNSAID)(4)Cl] and novel [Ru-2(dNSAID)(4)(H2O)(2)]PF6 complexes, where dNSAID = deprotonated carboxylate from the non-steroidal anti-inflammatory drugs (NSIDs), respectively: ibuprofen, Hibp (1) and aspirin, Hasp (2); naproxen, Hnpx (3) and indomethacin, Hind (4), have been prepared and characterized by optical spectroscopic methods. All of the compounds exhibit mixed valent Ru-2(II, III) cores where metal-metal bonds are stabilized by four drug-carboxylate bridging ligands in paddlewheel type structures. The diruthenium complexes and their parent NSAIDs showed no significant effects for Hep2 human larynx or T24/83 human bladder tumor. In contrast, the coordination of Ru-2(II,III) core led to synergistic effects that increased significantly the inhibition of C6 rat glioma proliferation in relation to the organic NSAIDs naproxen and ibuprofen, The possibility that the complexes Ru-2-ibp and Ru-2-npx may exert effects (anti-angiogenic and anti-matrix metalloprotease) that are similar to those exhibited by NAMI-A opens new horizons for in vivo C6 glioma model studies. (C) 2007 Elsevier Ltd. All rights reserved.
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The phenotypic pressure exerted by non-steroidal anti-inflammatory drugs (NSAIDs) on autochthonous and pathogenic microbiota remains sparsely known. In this study, we investigated if some NSAIDs increment or diminish the secretion of aspartyl-proteases (Sap) by Candida albicans grown under different phenotypes and oxygen availability using a set of SAP knock-out mutants and other set for genes (EFG1 and CPH1) that codify transcription factors involved in filamentation and protease secretion. Preconditioned cells were grown under planktonic and biofilm phenotypes, in normoxia and anoxia, in the presence of plasma concentrations of acetylsalicylic acid, diclofenac, indomethacin, nimesulide, piroxicam, ibuprofen, and acetaminophen. For diclofenac, indomethacin, nimesulide, and piroxicam the secretion rates of Sap by SAP1-6, EFG1. and CPH1 mutants were similar or, even, inferior to parental wildtype strain. This suggests that neither Sap 1-6 isoenzymes nor Efg1/Cph1 pathways may be entirely responsible for protease release when exposed to these NSAIDs. Ibuprofen and acetaminophen enhanced Sap secretion rates in three environmental conditions (normoxic biofilm, normoxic planktonic and anoxic planktonic). In other hand, aspirin seems to reduce the Sap-related pathogenic behavior of candidal biofilms. Modulation of Sap activity may occur according to candidal phenotypic state, oxygen availability, and type of NSAID to which the cells are exposed. (C) 2010 Elsevier Ltd. All rights reserved.
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Several noncoding microRNAs (miR or miRNA) have been shown to regulate the expression of drug-metabolizing enzymes and transporters. Xenobiotic drug-induced changes in enzyme and transporter expression may be associated with the alteration of miRNA expression. Therefore, this study investigated the impact of 19 xenobiotic drugs (e. g. dexamethasone, vinblastine, bilobalide and cocaine) on the expression of ten miRNAs (miR-18a, -27a, -27b, -124a, -148a, -324-3p, -328, -451, -519c and -1291) in MCF-7, Caco-2, SH-SY5Y and BE(2)-M17 cell systems. The data revealed that miRNAs were differentially expressed in human cell lines and the change in miRNA expression was dependent on the drug, as well as the type of cells investigated. Notably, treatment with bilobalide led to a 10-fold increase of miR-27a and a 2-fold decrease of miR-148a in Caco-2 cells, but no change of miR-27a and a 2-fold increase of miR-148a in MCF-7 cells. Neuronal miR-124a was generally down-regulated by psychoactive drugs (e. g. cocaine, methadone and fluoxetine) in BE(2)-M17 and SH-SY5Y cells. Dexamethasone and vinblastine, inducers of drug-metabolizing enzymes and transporters, suppressed the expression of miR-27b, -148a and -451 that down-regulate the enzymes and transporters. These findings should provide increased understanding of the altered gene expression underlying drug disposition, multidrug resistance, drug-drug interactions and neuroplasticity. Copyright (C) 2011 John Wiley & Sons, Ltd.
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Background and purpose: The discovery of the pharmacological functions of nitric oxide has led to the development of NO donor compounds as therapeutic agents. A new generation of ruthenium NO donors, cis-[Ru(NO)(bpy)(2)L]X(n) , has been developed, and our aim was to show that these complexes are able to lyse Trypanosoma cruzi in vitro and in vivo. Experimental approach: NO donors were incubated with T. cruzi and their anti-T. cruzi activities evaluated as the percentage of lysed parasites compared to the negative control. In vivo, trypanocidal activity was evaluated by observing the levels of parasitaemia, survival rate and elimination of amastigotes in mouse myocardial tissue. The inhibition of GAPDH was monitored by the biochemical reduction of NAD+ to NADH. Key results: The NO donors cis-[Ru(NO)(bpy)(2)L]X(n) presented inhibitory effects on T. cruzi GAPDH (IC(50) ranging from 89 to 153 mu M). The crystal structure of the enzyme shows that the inhibitory mechanism is compatible with S-nitrosylation of the active cysteine (cys166) site. Compounds cis-[Ru(NO)(bpy)(2)imN](PF(6))(3) and cis-[Ru(NO)(bpy)(2)SO(3)]PF(6), at a dose of 385 nmol center dot kg-1, yielded survival rates of 80 and 60%, respectively, in infected mice, and eradicated any amastigotes from their myocardial tissue. Conclusions and implications: The ruthenium compounds exhibited potent in vitro and in vivo trypanocidal activities at doses up to 1000-fold lower than the clinical dose for benznidazole. Furthermore, one mechanism of action of these compounds is via the S-nitrosylation of Cys166 of T. cruzi GAPDH. Thus, these compounds show huge potential as candidates for the development of new drugs for the treatment of Chagas`s disease. This article is commented on by Machado et al., pp. 258-259 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2010.00662.x and to view a related paper in this issue by Guedes et al. visit http://dx.doi.org/10.1111/j.1476-5381.2010.00576.x.
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Two new complexes of platinum(II) and silver(I) with acesulfame were synthesized. Acesulfame is in the anionic form acesulfamate (ace). The structures of both complexes were determined by X-ray crystallography. For K(2)[PtCl(2)(ace)(2)] the platinum atom is coordinated to two Cl(-) and two N-acesulfamate atoms forming a trans-square planar geometry. Each K(+) ion interacts with two oxygen atoms of the S(=O)(2) group of each acesulfamate. For the polymeric complex [Ag(ace)](n) the water molecule bridges between two crystallographic equivalent Agl atoms which are related each other by a twofold symmetry axis. Two Agl atoms, related to each other by a symmetry centre, make bond contact with two equivalent oxygen atoms. These bonds give rise to infinite chains along the unit cell diagonal in the ac plane. The in vitro cytotoxic analyses for the platinum complex using HeLa (human cervix cancer) cells show its low activity when compared to the vehicle-treated cells. The Ag(I) complex submitted to in vitro antimycobacterial tests, using the Microplate Alamar Blue (MABA) method, showed a good activity against Mycobacterium tuberculosis, responsible for tuberculosis, with a minimal inhibitory concentration (MIC) value of 11.6 mu M. The Ag(I) complex also presented a promising activity against Gram negative (Escherichia colt and Pseudomonas aeruginosa) and Gram positive (Enterococcus faecalis) microorganisms. The complex K(2)[PtCl(2)(ace)(2)] was also evaluated for antiviral properties against dengue virus type 2 (New Guinea C strain) in Vero cells and showed a good inhibition of dengue virus type 2 (New Guinea G strain) replication at 200 mu M, when compared to vehicle-treated cells. (C) 2010 Elsevier Inc. All rights reserved.
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Introduction: This study prospectively accessed the immune response to the inactivated influenza vaccine in renal transplant recipients receiving either azathioprine or mycophenolate mofetil (MMF). Side effects were investigated. Methods: Sixty-nine patients received one dose of inactivated trivalent influenza vaccine. Antihemagglutinin (HI) antibody response against each strain was measured before and one to six months after vaccination. Results: Geometric mean HI antibody titers for H1N1 and H3N2 strains increased from 2.57 and 2.44 to 13.45 (p = 0.001) and 7.20 (p < 0.001), respectively. Pre- and post-vaccination protection rates for H1N1 and H3N2 increased from 8.7% to 49.3% (p < 0.001); and 36.3% (p < 0.001) and seroconversion rates were 36% and 25.3%, respectively. There was no response to influenza B. The use of MMF reduced the H1N1 and H3N2 protection rates and the seroconversion rate for the H1N1 strain when compared with the use of azathioprine, and subjects transplanted less than 87 months also had inferior antibody response. Adverse events were mild and there were no change on renal function post-vaccination. Conclusion: Renal transplant patients vaccinated against influenza responded with antibody production for in. uenza A virus strains, but not for in. uenza B. Use of MMF and shorter time from transplantation decreased the immune response to the vaccine.
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Ruthenium compounds have been actively studied as metallodrugs for cancer therapy. Representatives of ruthenium-based antitumor drugs are the classes of ruthenium(III)-chlorido-(N-ligand)complexes, including the drugs namely NAMI-A and KP1019 in clinical trials, and ruthenium(II)-arene organometallics, with some compounds currently undergoing advanced preclinical testing. An alternative approach for tumor-inhibiting metallodrugs is the coordination of metal ions to organic pharmaceuticals. The combination of antitumor-active ruthenium ion with biologically-active pro-ligands in single compounds can result in the enhancement of activity, for example through synergistic effects. In the present article, some developments in the ruthenium-based antitumor drugs field are briefly highlighted and recent studies on mixed diruthenium-organic drugs as metallopharmaceuticals in cancer therapy are described. Novel organic pharmaceuticals-containing diruthenium(II, III)complexes have shown promising antitumor activity for C6 rat glioma - a model for glioblastoma multiforme (GBA).
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Three novel acetato-bridged dinuclear copper(II) complexes with 5-nitroimidazoles (CuAcNtrim) and the known copper-acetato-metronidazole have been prepared by an environment-friendly route and spectroscopically characterized. The CuAcNtrim compounds of formula [Cu(2)(mu-O(2)CCH(3))(4)Ntrim(2)], where Ntrim = metronidazole (1), secnidazole (2), tinidazole (3) or nimorazole (4), exhibit dimeric copper-acetato paddle-wheel structures with Ntrim axial ligands coordinated to copper(II) ions through the N(3) atoms of the imidazole rings. EPR data indicate antiferromagnetic behavior for this novel series of copper complexes. The constant coupling has been found to decrease along with the increasing of basicity of the Ntrim axial ligand. The CuAcNtrim complexes and the correspondent Ntrim parent drugs have shown radiosensitizer properties for Hep2 (human larynx cancer) cell line in vitro. The best enhancement of radiosensitizer activity upon coordination of the Ntrim drug to copper(II) has been found for the nimorazole compound which has the strongest Cu-Ntrim bond and exhibits the highest lipophilicity within the series of CuAcNtrim complexes. (C) 2010 Elsevier B.V. All rights reserved.
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Direct analysis, with minimal sample pretreatment, of antidepressant drugs, fluoxetine, imipramine, desipramine, amitriptyline, and nortriptyline in biofluids was developed with a total run time of 8 min. The setup consists of two HPLC pumps, injection valve, capillary RAM-ADS-C18 pre-column and a capillary analytical C 18 column connected by means of a six-port valve in backflush mode. Detection was performed with ESI-MS/MS and only 1 mu m of sample was injected. Validation was adequately carried out using FLU-d(5) as internal standard. Calibration curves were constructed under a linear range of 1-250 ng mL(-1) in plasma, being the limit of quantification (LOQ), determined as 1 ng mL(-1), for all the analytes. With the described approach it was possible to reach a quantified mass sensitivity of 0.3 pg for each analyte (equivalent to 1.1-1.3 fmol), translating to a lower sample consumption (in the order of 103 less sample than using conventional methods). (C) 2008 Elsevier B.V. All rights reserved.
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By virtue of the volume and nature of their attributions, including secondary school as well as problem-areas such as security and traffic, the Brazilian states are the ultimate responsible entities for young people. This study argues in favour of granting greater freedom for the states to define their own public policy parameters to deal with local features and to increase the degree of learning about such actions at the national level. In empirical terms, the study assesses the impacts of new laws, such as the new traffic code (from the joint work with Leandro Kume, EPGE/FGV doctor’s degree student) and traces the statistics for specific questions like drugs, violence and car accidents. The findings show that these questions produce different results for young men and women.The main characters in these dramas are young single males, suggesting the need for more distinguished public policies according not only to age, but also by gender. The study also reveals that the magnitude of these problems changes according to the youth’s social class. Prisons concern poorer men (except for the functional illiterate) while fatal car accidents and the confessed use of drugs concern upper-class boys.
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Plantas da família Guttiferae apresentam diversas atividades biológicas sendo Hypericum o gênero mais importante devido às atividades antidepressiva, antibacteriana e antiviral de algumas espécies. Hypericum connatum, utilizado no sul do Brasil para o tratamento de feridas de boca, demonstrou atividade contra o lentivírus, responsável pela imunodeficiência felina. Objetivo: isolar e identificar as substâncias majoritárias de H. connatum e testar a atividade de extratos obtidos das partes aéreas e raízes e das substâncias isoladas frente a duas cepas do herpesvírus simples tipo 1 (HSV-1). Método: foram obtidos frações nhexano, diclorometano e metanol e extratos bruto, aquosos a diferentes temperaturas e hidro-etanólico das partes aéreas e raízes. As frações n-hexano e metanólica das partes aéreas foram submetidas à coluna cromatográfica para o isolamento de substâncias. Os extratos e substâncias isoladas foram testados frente ao HSV-1, cepas KOS e ATCC-VR733. Determinou-se a concentração máxima não tóxica (CMNT) à célula e a concentração que provoca alteração morfológica em 50% das células (CC50) pela técnica da alteração morfológica celular, utilizando-se células VERO, linhagem ATCC CCL-81. A avaliação da atividade antiviral foi realizada em placas de microtitulação e medida pela inibição do efeito citopático (ECP) provocado pelo vírus. Resultados e Conclusões: da fração n-hexano foi isolado hiperbrasilol B, da fração metanólica foram isolados amentoflavona, hiperosídeo e guaijaveriana, além de um flavonol de estrutura ainda não definida (HCN3). A fração n-hexano e o extrato bruto das raízes inibiram o ECP das cepas KOS e ATCC-VR733. Os demais extratos testados não apresentaram atividade antiviral. Dentre as substâncias analisadas, hiperbrasilol B, amentoflavona e HCN3 foram ativos frente às duas cepas. Os flavonóides hiperosídeo e guaijaverina não apresentaram atividade anti-HSV-1.
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Sulfated polysaccharides (SP) are widely distributed in animals and seaweeds tissues. These polymers have been studied in light of their important pharmacological activities, such as anticoagulant, antioxidant, antitumoral, anti-inflammatory, and antiviral properties. On other hand, SP potential to synthesize biomaterials like as nanoparticules has not yet been explored. In addition, to date, SP have only been found in six plants and all inhabit saline environments. However, the SP pharmacological plant activities have not been carrying out. Furthermore, there are no reports of SP in freshwater plants. Thus, do SP from marine plants show pharmacological activity? Do freshwater plants actually synthesize SP? Is it possible to synthesize nanoparticles using SP from seaweed? In order to understand this question, this Thesis was divided into tree chapters. In the first chapter a sulfated polysaccharide (SPSG) was successfully isolated from marine plant Halodule wrightii. The data presented here showed that the SPSG is a 11 kDa sulfated heterogalactan contains glucose and xylose. Several assays suggested that the SPSG possessed remarkable antioxidant properties in different in vitro assays and an outstanding anticoagulant activity 2.5-fold higher than that of heparin Clexane® in the aPTT test; in the next chapter using different tools such as chemical and histological analyses, energy-dispersive X-ray analysis (EDXA), gel electrophoresis and infra-red spectroscopy we confirm the presence of sulfated polysaccharides in freshwater plants for the first time. Moreover, we also demonstrate that SP extracted from E. crassipes root has potential as an anticoagulant compound; and in last chapter a fucan, a sulfated polysaccharide, extracted from the brown seaweed was chemically modified by grafting hexadecylamine to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed nanosized particles. The degree of substitution for hydrophobic chains of 1H NMR was approximately 93%. SNFfuc-TBa125 in aqueous media had a mean diameter of 123 nm and zeta potential of -38.3 ± 0.74 mV, measured bydynamic light scattering. Tumor-cell (HepG2, 786, H-S5) proliferation was inhibited by 2.0 43.7% at SNFuc concentrations of 0.05 0.5 mg/ mL and RAEC non-tumor cell line proliferation displayed inhibition of 8.0 22.0%. On the other hand, nanogel improved CHO and RAW non-tumor cell line proliferation in the same concentration range. Flow cytometric analysis revealed that this fucan nanogel inhibited 786 cell proliferation through caspase and caspaseindependent mechanisms. In addition, SNFuc blocks 786 cell passages in the S and G2-M phases of the cell cycle
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This thesis was devoted to the development of innovative oral delivery systems for two different molecules. In the first part, microparticles (MPs) based on xylan and Eudragit® S- 100 were produced and used to encapsulate 5-aminosalicylic acid for colon delivery. Xylan was extracted from corn cobs and characterized in terms of its physicochemical, rheological and toxicological properties. The polymeric MPs were prepared by interfacial cross-linking polymerization and spray-drying and characterized for their morphology, mean size and distribution, thermal stability, crystallinity, entrapment efficiency and in vitro drug release. MPs with suitable physical characteristics and satisfactory yields were prepared by both methods, although the spray-dried systems showed higher thermal stability. In general, spraydried MPs would be preferable systems due to their thermal stability and absence of toxic agents used in their preparation. However, drug loading and release need to be optimized. In the second part of this thesis, oil-in-water microemulsions (O/W MEs) based on mediumchain triglycerides were formulated as drug carriers and solubility enhancers for amphotericin B (AmB). Phase diagrams were constructed using surfactant blends with hydrophiliclipophilic balance values between 9.7 and 14.4. The drug-free and drug-loaded MEs presented spherical non-aggregated droplets around 80 and 120 nm, respectively, and a low polydispersity index. The incorporation of AmB was high and depended on the volume fraction of the disperse phase. These MEs did not reduce the viability of J774.A1 macrophage-like cells for concentrations up to 25 μg/mL of AmB. Therefore, O/W MEs based on propylene glycol esters of caprylic acid may be considered as suitable delivery systems for AmB