Mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotics.

CVD affect a large proportion of the world's population, with dyslipidaemia as the major risk factor. The regular consumption of both probiotic bacteria and yeast has been associated with improvement in the serum lipid profile. Thus, the present review aims to describe and discuss the potential mechanisms responsible for the hypocholesterolaemic effect of regular consumption of probiotic bacteria and yeast. Regarding the hypocholesterolaemic effect of probiotic bacteria, the potential mechanisms responsible include: deconjugation of bile salts; modulation of lipid metabolism; and decreased absorption of intestinal cholesterol through co-precipitation of intestinal cholesterol with the deconjugated bile salts, incorporation and assimilation of cholesterol in the cell membrane of the probiotics, intestinal conversion of cholesterol in coprostanol, and inhibition of the expression of the intestinal cholesterol transporter Niemann-Pick C1 like 1 (NPC1L1) in the enterocytes. The potential mechanisms responsible for the hypocholesterolaemic effect of probiotic yeasts include: deconjugation of bile salts; co-precipitation of intestinal cholesterol with the deconjugated bile salts; incorporation and assimilation of cholesterol in the cell membrane; and inhibition of hepatic cholesterol synthesis. The regular consumption of probiotic bacteria and yeast, as a non-pharmaceutical approach to help manage cardiovascular risk, holds promise, according to the beneficial hypocholesterolaemic effects described herein. However, the hypocholesterolaemic effects vary according to the strains used, the physiological state of the host, and the type of diet to which the probiotics are added. Further studies are necessary to fill the gaps with regard to the knowledge related to this topic.

Evolutionary conservation of actin-binding proteins in Trypanosoma cruzi and unusual subcellular localization of the actin homologue.

The actin cytoskeleton controls pivotal cellular processes such as motility and cytokinesis, as well as cell-cell and cell-substrate interactions. Assembly and spatial organization of actin filaments are dynamic events regulated by a large repertoire of actin-binding proteins. This report presents the first detailed characterization of the Trypanosoma cruzi actin (TcActin). Protein sequence analysis and homology modelling revealed that the overall structure of T. cruzi actin is conserved and that the majority of amino-acid changes are concentrated on the monomer surface. Immunofluorescence assays using specific polyclonal antibody against TcActin revealed numerous rounded and punctated structures spread all over the parasitic body. No pattern differences could be found between epimastigotes and trypomastigotes or amastigotes. Moreover, in detergent extracts, TcActin was localized only in the soluble fraction, indicating its presence in the G-actin form or in short filaments dissociated from the microtubule cytoskeleton. The trypanosomatid genome was prospected to identify actin-binding and actin-related conserved proteins. The main proteins responsible for actin nucleation and treadmilling in higher eukaryotes are conserved in T. cruzi.

Kinetically Selective Inhibitors of Histone Deacetylase 2 (HDAC2) as Cognition Enhancers.

Aiming towards the development of novel nootropic therapeutics to address the cognitive impairment common to a range of brain disorders, we set out to develop highly selective small molecule inhibitors of HDAC2, a chromatin modifying histone deacetylase implicated in memory formation and synaptic plasticity. Novel ortho-aminoanilide inhibitors were designed and evaluated for their ability to selectively inhibit HDAC2 versus the other Class I HDACs. Kinetic and thermodynamic binding properties were essential elements of our design strategy and two novel classes of ortho-aminoanilides, that exhibit kinetic selectivity (biased residence time) for HDAC2 versus the highly homologous isoform HDAC1, were identified. These kinetically selective HDAC2 inhibitors (BRD6688 and BRD4884) increased H4K12 and H3K9 histone acetylation in primary mouse neuronal cell culture assays, in the hippocampus of CK-p25 mice, a model of neurodegenerative disease, and rescued the associated memory deficits of these mice in a cognition behavioural model. These studies demonstrate for the first time that selective pharmacological inhibition of HDAC2 is feasible and that inhibition of the catalytic activity of this enzyme may serve as a therapeutic approach towards enhancing the learning and memory processes that are affected in many neurological and psychiatric disorders.

PET imaging demonstrates histone deacetylase target engagement and clarifies brain penetrance of known and novel small molecule inhibitors in rat.

Histone deacetylase (HDAC) enzymes have been demonstrated as critical components in maintaining chromatin homeostasis, CNS development, and normal brain function. Evidence in mouse models links HDAC expression to learning, memory, and mood-related behaviors; small molecule HDAC inhibitor tool compounds have been used to demonstrate the importance of specific HDAC subtypes in modulating CNS-disease-related behaviors in rodents. So far, no direct evidence exists to understand the quantitative changes in HDAC target engagement that are necessary to alter biochemistry and behavior in a living animal. Understanding the relationship between target engagement and in vivo effect is essential in refining new ways to alleviate disease. We describe here, using positron emission tomography (PET) imaging of rat brain, the in vivo target engagement of a subset of class I/IIb HDAC enzymes implicated in CNS-disease (HDAC subtypes 1, 2, 3, and 6). We found marked differences in the brain penetrance of tool compounds from the hydroxamate and benzamide HDAC inhibitor classes and resolved a novel, highly brain penetrant benzamide, CN147, chronic treatment with which resulted in an antidepressant-like effect in a rat behavioral test. Our work highlights a new translational path for understanding the molecular and behavioral consequences of HDAC target engagement.

Avaliação toxicológica pré-clínica do chá das folhas de Morus nigra L. (Moraceae) / Pre-clinical toxicological evaluation of tea from the leaves of Morus nigra L. (Moraceae)

O objetivo desse estudo foi realizar um ensaio toxicológico pré-clínico para analisar a toxicidade do chá das folhas de Morus nigra L. (Moraceae). A toxicidade subcrônica do chá (CF-Mn) foi avaliada durante 30 dias por via oral em ratos. Ao grupo controle foi administrado água, para comparação. Durante o período experimental foi avaliada a presença de sinais de toxicidade, variação do peso corporal, e o consumo de líquido e alimento. Ao final do experimento o sangue dos animais foi retirado para análise de parâmetros hematológicos e bioquímicos. Não foram observados mortalidade e sinais de toxicidade indicando baixa toxicidade da planta. Não houve alterações nos parâmetros hematológicos e bioquímicos. Nas condições do estudo, o CF-Mn pode ser considerado de baixa toxicidade, pois não produziu efeitos tóxicos nos animais tratados.

The aim of this study was to carry out a pre-clinical toxicological assay to analyze the toxicity of tea from the leaves of Morus nigra L. (Moraceae). The subchronic toxicity of this tea (CF-Mn) was orally evaluated during 30 days in rats. The control group was given water for comparison. During the experimental period, signs of toxicity, body weight variation, and water and food consumption were assessed. At the end of the experiment, the blood of animals was removed for analysis of hematological and biochemical parameters. No mortality and no toxicity signs were observed, indicating low toxicity of the plant. There was no alteration in the hematological and biochemical parameters. Under the study conditions, CF-Mn can be considered of low toxicity since it did not produce toxic effects in treated animals.

FK506, a secondary metabolite produced by Streptomyces, presents a novel antiviral activity against Orthopoxvirus infection in cell culture.

AIMS: To investigate the antiviral potential of the macrolide FK506, produced by Streptomyces tsukubaensis, against Orthopoxvirus infection in cell culture, and determine the replicative stage of viral cycle affected by the treatment. METHODS AND RESULTS: Cell lines were infected with different Orthopoxviruses and treated with FK506. The macrolide inhibited the replication of the prototypic Orthopoxvirus, vaccinia virus strain WR, with an IC50 of 12.05 micromol l(-1). Progeny production of other Orthopoxviruses was also inhibited by FK506 at noncytotoxic concentrations, as evaluated by the neutral-red uptake assay and metabolic labelling of cellular proteins. By Western blot assay, we detected a severe inhibition (approximately 87.6% +/- 2.78%) of VV strain WR post-replicative protein synthesis. A similar reduction of virus DNA accumulation, as observed by slot-blot assay, probably accounts for the subsequent inhibition of virus late proteins. CONCLUSIONS: The macrolide FK506, isolated from S. tsukubaensis, presents a novel anti-poxvirus activity, probably targeting the stage of DNA replication during Orthopoxvirus infection. SIGNIFICANCE AND IMPACT OF THE STUDY: The secondary metabolite FK506, isolated from the culture filtrate of S. tsukubaensis, shows a pleiotropic range of activities, and might be a valuable tool as a lead structure in the generation of non-immunosuppressant analogues with strong anti-poxvirus activity.

Clinical and radiographic presentation and preparation of the prototyping model for pre-surgical planning in Apert's syndrome.

Acrocephalosyndactyly, or Apert's syndrome, described nearly a century ago, is a craniofacial dysostosis, an autosomal dominant condition characterized by severe development disturbances of the craniofacial region including bilateral coronal synostosis associated with midface hypoplasia, exophthalmia, hypertelorism, symmetric syndactyly of the hands and feet, cone-shaped calvarium, pharyngeal attenuation and malocclusion. The aim of this study was to assess clinical and computed tomography (CT) imaging patterns of a non-operated patient with Apert's syndrome, correlating the cranium, face and the skull base bone abnormalities. Three-dimensional images were generated from spiral CT scans in order to produce a prototyping model in polyamide material. Clinical examination determined that syndactyly of the hands and feet, pseudocleft in the midline palate and midface hypoplasia were present. The surgical model allowed the analysis of some abnormalities regarding to calvaria morphology, nasal bones and maxilla, improving the criteria for a case diagnosis and surgical plan.

Procollagen alpha 1(I) transcripts in cells near the interface of coralline implants in rats, detected by in situ hybridization.

Cells procollagen alpha 1(I) transcripts were demonstrated at the interface of natural coral mineral implanted in the femur of rats after 7, 14, 21 and 28 days by in situ hybridization with digoxigenin-labelled RNA probes. Procollagen alpha 1(I) transcripts were detectable in osteoblasts between 7 and 28 days after implantation. As early as 7 days after implantation, procollagen alpha 1(I) RNA expression was also demonstrated in fibroblasts; the transcripts steady state levels decreased until the 28th day, when they subsided completely. The development of bone was significantly during the 4 weeks of implantation. Inhibition of bone development by the coralline material could not be recorded.

Protein synthesis inhibitory activity in culture filtrates from new strains of Streptomyces isolated from Brazilian tropical soils.

AIMS: To investigate the effect of the culture supernatants from three newly isolated Streptomyces strains, 221, 235 and 606 on eukaryotic cells. METHODS AND RESULTS: Cell lines were treated with the culture filtrates and assayed for protein synthesis by metabolic labelling, followed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis. RNA synthesis was investigated by [5-3H]uridine incorporation. The three culture filtrates presented a strong inhibitory activity, reducing total protein synthesis of different eukaryotic cell lines by more than 85%. No effect on cellular RNA synthesis was detected. The culture filtrates did not affect the growth of the prokaryotic cells tested. CONCLUSIONS: These new Streptomyces strains, recently isolated from Brazilian tropical soils, produce molecule(s) with inhibitory activity specific to eukaryote protein synthesis. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptomyces strains 221, 235 and 606, probably representing new species, might produce new bioactive compound(s), and can be used as valuable tools to study the protein synthesis pathway in eukaryotes.