205 research outputs found
Microbiome-gut-brain axis and toll-like receptors in parkinson\u2019s disease
Parkinson’s disease (PD) is a progressively debilitating neurodegenerative disease characterized by α-synucleinopathy, which involves all districts of the brain-gut axis, including the central, autonomic and enteric nervous systems. The highly bidirectional communication between the brain and the gut is markedly influenced by the microbiome through integrated immunological, neuroendocrine and neurological processes. The gut microbiota and its relevant metabolites interact with the host via a series of biochemical and functional inputs, thereby affecting host homeostasis and health. Indeed, a dysregulated microbiota-gut-brain axis in PD might lie at the basis of gastrointestinal dysfunctions which predominantly emerge many years prior to the diagnosis, corroborating the theory that the pathological process is spread from the gut to the brain. Toll-like receptors (TLRs) play a crucial role in innate immunity by recognizing conserved motifs primarily found in microorganisms and a dysregulation in their signaling may be implicated in α-synucleinopathy, such as PD. An overstimulation of the innate immune system due to gut dysbiosis and/or small intestinal bacterial overgrowth, together with higher intestinal barrier permeability, may provoke local and systemic inflammation as well as enteric neuroglial activation, ultimately triggering the development of alpha-synuclein pathology. In this review, we provide the current knowledge regarding the relationship between the microbiota-gut–brain axis and TLRs in PD. A better understanding of the dialogue sustained by the microbiota-gut-brain axis and innate immunity via TLR signaling should bring interesting insights in the pathophysiology of PD and provide novel dietary and/or therapeutic measures aimed at shaping the gut microbiota composition, improving the intestinal epithelial barrier function and balancing the innate immune response in PD patients, in order to influence the early phases of the following neurodegenerative cascade
Toll-Like Receptor 4 Modulates Small Intestine Neuromuscular Function through Nitrergic and Purinergic Pathways
Objective: Toll-like receptors (TLRs) play a pivotal role in the homeostatic microflora-host crosstalk. TLR4-mediated modulation of both motility and enteric neuronal survival has been reported mainly for colon with limited information on the role of TLR4 in tuning structural and functional integrity of enteric nervous system (ENS) and in controlling small bowel motility.
Methods: Male TLR4 knockout (TLR4-/-, 9 \ub1 1 weeks old) and sex- and age-matched wild-type (WT) C57BL/6J mice were used for the experiments. Alterations in ENS morphology and neurochemical code were assessed by immunohistochemistry whereas neuromuscular function was evaluated by isometric mechanical activity of ileal preparations following receptor and non-receptor-mediated stimuli and by gastrointestinal transit.
Results: The absence of TLR4 induced gliosis and reduced the total number of neurons, mainly nNOS+ neurons, in ileal myenteric plexus. Furthermore, a lower cholinergic excitatory response with an increased inhibitory neurotransmission was found together with a delayed gastrointestinal transit. These changes were dependent on increased ileal non-adrenergic non-cholinergic (NANC) relaxations mediated by a complex neuronal-glia signaling constituted by P2X7 and P2Y1 receptors, and NO produced by nNOS and iNOS.
Conclusion: We provide novel evidence that TLR4 signaling is involved in the fine-tuning of P2 receptors controlling ileal contractility, ENS cell distribution, and inhibitory NANC neurotransmission via the combined action of NO and adenosine-5\u2032-triphosphate (ATP). For the first time, this study implicates TLR4 at regulating the crosstalk between glia and neurons in small intestine and helps to define its role in gastrointestinal motor abnormalities during dysbiosis
Boswellia serrata Preserves Intestinal Epithelial Barrier from Oxidative and Inflammatory Damage
Aminosalicylates, corticosteroids and immunosuppressants are currently the therapeutic choices in inflammatory bowel diseases (IBD), however, with limited remission and often serious side effects. Meanwhile complementary and alternative medicine (CAM) use is increasing, particularly herbal medicine. Boswellia serrata is a traditional Ayurvedic remedy with anti-inflammatory properties, of interest for its usefulness in IBDs. The mechanism of this pharmacological potential of Boswellia serrata was investigated in colonic epithelial cell monolayers exposed to H2O2 or INF-\u3b3+TNF-\u3b1, chosen as in vitro experimental model of intestinal inflammation. The barrier function was evaluated by the transepithelial electrical resistance (TEER) and paracellular permeability assay, and by the tight junction proteins (zonula occludens-1, ZO-1 and occludin) immunofluorescence. The expression of phosphorylated NF-\u3baB and reactive oxygen species (ROS) generation were determined by immunoblot and cytofluorimetric assay, respectively. Boswellia serrata oleo-gum extract (BSE) and its pure derivative acetyl-11-keto-\u3b2-boswellic acid (AKBA), were tested at 0.1-10 \u3bcg/ml and 0.027\u3bcg/ml, respectively. BSE and AKBA safety was demonstrated by no alteration of intestinal cell viability and barrier function and integrity biomarkers. H2O2 or INF-\u3b3+TNF-\u3b1 treatment of Caco-2 cell monolayers significantly reduced TEER, increased paracellular permeability and caused the disassembly of tight junction proteins occludin and ZO-1. BSE and AKBA pretreatment significantly prevented functional and morphological alterations and also the NF-\u3baB phosphorylation induced by the inflammatory stimuli. At the same concentrations BSE and AKBA counteracted the increase of ROS caused by H2O2 exposure. Data showed the positive correlation of the antioxidant activity with the mechanism involved in the physiologic maintenance of the integrity and function of the intestinal epithelium. This study elucidates the pharmacological mechanisms mediated by BSE, in protecting intestinal epithelial barrier from inflammatory damage and supports its use as safe adjuvant in patients affected by IBD
Saccharomyces boulardii CNCM I-745 supplementation reduces gastrointestinal dysfunction in an animal model of IBS
We evaluated the effect of Saccharomyces boulardii CNCM I-745 on intestinal neuromuscular anomalies in an IBS-type mouse model of gastrointestinal motor dysfunctions elicited by Herpes Simplex Virus type 1 (HSV-1) exposure.Mice were inoculated intranasally with HSV-1 (102 PFU) or vehicle at time 0 and 4 weeks later by the intragastric (IG) route (108 PFU). Six weeks after IG inoculum, mice were randomly allocated to receive oral gavage with either S. boulardii (107 CFU/day) or vehicle. After 4 weeks the following were determined: a) intestinal motility using fluorescein-isothiocyanate dextran distribution in the gut, fecal pellet expulsion, stool water content, and distal colonic transit of glass beads; b) integrity of the enteric nervous system (ENS) by immunohistochemistry on ileal whole-mount preparations and western blot of protein lysates from ileal longitudinal muscle and myenteric plexus; c) isometric muscle tension with electric field and pharmacological (carbachol) stimulation of ileal segments; and d) intestinal inflammation by levels of tumor necrosis factor α, interleukin(IL)-1β, IL-10 and IL-4.S. boulardii CNCM I-745 improved HSV-1 induced intestinal dysmotility and alteration of intestinal transit observed ten weeks after IG inoculum of the virus. Also, the probiotic yeast ameliorated the structural alterations of the ENS induced by HSV-1 (i.e., reduced peripherin immunoreactivity and expression, increased glial S100β protein immunoreactivity and neuronal nitric oxide synthase level, reduced substance P-positive fibers). Moreover, S. boulardii CNCM I-745 diminished the production of HSV-1 associated pro-inflammatory cytokines in the myenteric plexus and increased levels of anti-inflammatory interleukins.S. boulardii CNCM I-745 ameliorated gastrointestinal neuromuscular anomalies in a mouse model of gut dysfunctions typically observed with irritable bowel syndrome
Protective effects of \u3c8 taraxasterol 3-O-myristate and arnidiol 3-O-myristate isolated from Calendula officinalis on epithelial intestinal barrier
The triterpene esters psi taraxasterol-3-O-myristate (1) and amidio1-3-O-myristate (2) were tested for their ability to protect epithelial intestinal barrier in an in vitro model. Their effects on ROS production and on trans-epithelial resistance were investigated on CaCo-2 cell monolayers both in basal and stress -induced conditions. Both compounds were able to modulate the stress damage induced by H2O2 and INF gamma + TNF alpha, showing a potential use as model compounds for the study of new therapeutic agents for intestinal inflammations
Influence of Tilia tomentosa Moench Extract on Mouse Small Intestine Neuromuscular Contractility
Functional gastrointestinal disorders (FGIDs) are characterized by abdominal pain, bloating and bowel disturbances. FGID therapy is primarily symptomatic, including treatment with herbal remedies. Flower extract of Tilia tomentosa Moench (TtM) is occasionally used as an anti-spasmodic in popular medicine. Since its effect on intestinal response is unknown, we evaluated the influence of TtM extract on small intestine contractility. Ileal preparations from C57BL/6J mice were mounted in organ baths to assess changes in muscle tension, following addition of TtM extract (0.5-36 mu g/mL) or a vehicle (ethanol). Changes in contractile response to receptor- and non-receptor-mediated stimuli were assessed in ileal preparations pretreated with 12 mu g/mL TtM. Alterations in the enteric nervous system neuroglial network were analyzed by confocal immunofluorescence. Increasing addition of TtM induced a marked relaxation in ileal specimens compared to the vehicle. Pretreatment with TtM affected cholinergic and tachykininergic neuromuscular contractions as well as K+-induced smooth muscle depolarization. Following incubation with TtM, a significant reduction in non-adrenergic non-cholinergic-mediated relaxation sensitive to N omega-Nitro-L-arginine methyl ester hydrochloride (pan-nitric oxide synthase inhibitor) was found. In vitro incubation of intestinal specimens with TtM did not affect the myenteric plexus neuroglial network. Our findings show that TtM-induced intestinal relaxation is mediated by nitric oxide pathways, providing a pharmacological basis for the use of TtM in FGIDs
Caracterización hidroquímica de cenotes del Estado de Yucatán, México
El acuífero del Estado de Yucatán constituye uno de los más vulnerables en el país, debido a diversos factores tanto antropogénicos como naturales que afectan su calidad. En el presente trabajo de investigación, se evaluó un grupo de cenotes del Estado de Yucatán, estableciendo sus características mediante una serie de análisis fisicoquímicos realizados a las muestras de agua y la integración de los datos obtenidos en diagramas hidroquímicos. La naturaleza de su composición química está relacionada a la interacción agua-roca con una facie dominante de Ca-Mg-HCO₃ como resultado de la disolución de minerales como calcita, aragonita y dolomita. De acuerdo a su calidad para propósitos de irrigación se consideró que es adecuada para emplearse en cultivos salino tolerantes. Desafortunadamente, su calidad como agua de consumo no es favorable, al presentar salinidad, sólidos totales disueltos, dureza, amonio y arsénico con valores superiores a las normas definidas para este uso.The aquifer of the State of Yucatan is one of the most vulnerable in the country, due to various anthropogenic and natural factors that affect its quality. In the present research work, a group of cenotes from the State of Yucatán was evaluated, establishing its characteristics through a series of physicochemical analyzes performed on water samples and the integration of data obtained in hydrochemical diagrams. The nature of its chemical composition is related to water-rock interaction with a dominant Ca-Mg-HCO₃ facie as a result of the dissolution of minerals such as calcite, aragonite and dolomite. According to its quality for irrigation purposes, it was considered suitable for use in saline tolerant crops. Unfortunately, its quality as drinking water is unsuitable, since it presents salinity, total dissolved solids, hardness, ammonium, and arsenic values higher than the standards defined for this use
Impact of the COVID-19 lockdown on psychological health and nutritional habits in Italy: results from the #PRESTOinsieme study
Spray-drying Microencapsulation of an Extract from Tilia tomentosa Moench Flowers: Physicochemical Characterization and in Vitro Intestinal Activity
Silver linden (Tilia tomentosa Moench, TtM) flowers possess several health-promoting properties, especially at the neurological level, such as intestinal relaxation activity associated with specific flavonols, particularly quercetin and kaempferol derivatives. However, such molecules are susceptible to degradation upon different triggers like heat, light and extreme pH values. To overcome the scarce stability of TtM flowers bioactive molecules and make them suitable for developing functional food and supplements, we applied microencapsulation. Spray-drying microencapsulation of TtM flowers extract was performed using three starch-derived wall materials: maltodextrin 12 DE (MD12) and 19 DE (MD19), and OSA-modified starch (OSA-S). The stability of total phenols, flavanols, and antioxidant capacity was monitored for 70 days under accelerated stress conditions (40 °C/70% RH) by HPLC and spectrophotometric methods, and the intestinal contractile activity was tested in a murine model. In comparison to MD12 and MD19, OSA-S stood out for the higher encapsulation efficiency of quercetin and kaempferol glycosides (+ 36-47% compared to MD12 and + 18-24% compared to MD19) and stability thereof (half-life on average + 30% compared to MD12 and + 51% compared to MD19). The intestinal contractile activity of OAS-S powders resulted comparable to the original extract, indicating that flavonols were biologically active and accessible. Our results underly the potential advantages of OSA-S encapsulated formulation as a functional ingredient for the development of nutraceutical products
Thalidomide is Associated With Increased T Cell Activation and Inflammation in Antiretroviral-naive HIV-infected Individuals in a Randomised Clinical Trial of Efficacy and Safety
Trial Design: Open-label, randomised, controlled, pilot proof-of-concept clinical trial. Methods: Participants: Antiretroviral naive adult males with CD4 count >= 350 cells/mm(3). Interventions: Patients were randomised to receive thalidomide 200 mg QD for 3 weeks (Thalidomide group) or not (Control group) and followed for 48 weeks. Objective: We hypothesized that short-term Thalidomide use would reduce HIV related inflammation and HIV replication among antiretroviral naive HIV infected individuals. Outcome: Viral loads, CD4/CD8 counts, ultra-sensitive C-reactive protein (US-CRP), cell activation markers, and plasma lipopolysaccharide (LPS) were analyzed. Randomisation: Unrestricted randomisation. Blinding: No blinding was used. Results: Numbers randomised: Thirty recruited individuals were randomised to Thalidomide (16 patients) or Control (14 patients) groups. Recruitment: Patients were recruited from April 2011 to January 2013. Outcome: Viral loads remained stable in both groups. During thalidomide treatment, a decrease in CD4/CD8 ratio (p = 0.04), a decrease in CD4 count (p = 0.04), an increase in cell activation calculated by the percentage of CD38 (+)/HLA-DR+ CD8 cells (p < 0.05) and an increase in US-CRP (p < 0.01) were observed in the Thalidomide group, with all parameters returning to baseline levels after thalidomide interruption. We confirmed that thalidomide increased HIV replication in vitro of 6 of 7 samples from long-term antiretroviral suppressed individuals. Harms: No class 3/4 adverse events occurred. Conclusions: Short-termuse of thalidomide led to an intense transient increase in T cell activation and inflammation, with a decrease in the CD4(+) cell count without changes to the CD8(+) cell count. We confirmed that thalidomide acts in vitro as a latency reversal agent and speculate that the in vivo results obtained were due to an increase in HIV replication. (C) 2017 The Authors. Published by Elsevier B.V.Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)Univ Fed São Paulo, Lab Retrovirol, São Paulo, BrazilFiocruz MS, Inst Oswaldo Cruz, Lab Interdisciplinar Pesquisas Med, Rio De Janeiro, BrazilSecretaria Municipal Saude Antonio Ribeiro Neto, Rio De Janeiro, BrazilOncohiv, Rio De Janeiro, BrazilUniv Fed Rio de Janeiro, Rio De Janeiro, BrazilInst Fed Educ Ciencia & Tecnol Rio de Janeiro IF, Rio De Janeiro, BrazilUniv Fed São Paulo, Lab Retrovirol, São Paulo, BrazilFAPESP: 04/15856-9Web of Scienc
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