10 research outputs found
Jaboticaba (Myrciaria jaboticaba) powder consumption improves the metabolic profile and regulates gut microbiome composition in high-fat diet-fed mice
The consumption of a high-fat diet can cause metabolic syndrome and induces host gut microbial dysbiosis and non-alcoholic fatty liver disease (NAFLD). We evaluated the effect of polyphenol-rich jaboticaba peel and seed powder (JPSP) on the gut microbial community composition and liver health in a mouse model of NAFLD. Three-month-old C57BL/6 J male mice, received either a control (C, 10% of lipids as energy, n = 16) or high-fat (HF, 50% of lipids as energy, n = 64) diet for nine weeks. The HF mice were randomly subdivided into four groups (n = 16 in each group), three of which (HF-J5, HF-J10, and HF-J15) were supplemented with dietary JPSP for four weeks (5%, 10%, and 15%, respectively). In addition to attenuating weight gain, JPSP consumption improved dyslipidemia and insulin resistance. In a dose-dependent manner, JPSP consumption ameliorated the expression of hepatic lipogenesis genes (AMPK, SREBP-1, HGMCoA, and ABCG8). The effects on the microbial community structure were determined in all JPSP-supplemented groups; however, the HF-J10 and HF-J15 diets led to a drastic depletion in the species of numerous bacterial families (Bifidobacteriaceae, Mogibacteriaceae, Christensenellaceae, Clostridiaceae, Dehalobacteriaceae, Peptococcaceae, Peptostreptococcaceae, and Ruminococcaceae) compared to the HF diet, some of which represented a reversal of increases associated with HF. The Lachnospiraceae and Enterobacteriaceae families and the Parabacteroides, Sutterella, Allobaculum, and Akkermansia genera were enriched more in the HF-J10 and HF-J15 groups than in the HF group. In conclusion, JPSP consumption improved obesity-related metabolic profiles and had a strong impact on the microbial community structure, thereby reversing NAFLD and decreasing its severity.This work was financially supported by Brazilian funding: FAPERJ – Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ: E-26/202.677/2018, E-26/010.002203/2019) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brazil (CAPES) – Finance code 001. Benjamin Willing was supported by the Canada Research Chair Program and his laboratory received funding from the Canadian Natural Science and Engineering Research Council (NSERC
Determination of the binding properties of p -cresyl glucuronide to human serum albumin
International audiencep-Cresyl glucuronide (p-CG) is a by-product of tyrosine metabolism that accumulates in patients with end-stage renal disease. p-CG binding to human serum albumin in physiological conditions (37 degrees C, pH 7.40) was studied by ultrafiltration (MWCO 10kDa) and data were analyzed assuming one binding site. The estimated value of the association constant was 2.77x10(3)M(-1) and a maximal stoichiometry of 3.80mol per mole. At a concentration relevant for end-stage renal patients, p-CG was 23% bound to albumin. Competition experiments, using fluorescent probes, demonstrated that p-CG did not bind to Sudlow's site I or site II. The p-CG did not interfere with the binding of p-cresyl-sulfate or indoxyl sulfate to serum albumin
Role of Natural Antioxidants from Functional Foods in Neurodegenerative and Metabolic Disorders
International audienc
Systemic inflammation and oxidative stress in hemodialysis patients are associated with down-regulation of Nrf2.
BackgroundOxidative stress and inflammation are common features and the main mediators of progression of chronic kidney disease (CKD) and its cardiovascular complications. Under normal conditions, oxidative stress activates the transcription factor, nuclear factor E2-related factor 2 (Nrf2), which is the master regulator of genes encoding antioxidant and detoxifying enzymes and related proteins. The available data on expression of Nrf2 and its key target gene products in CKD patients is limited. We therefore investigated this topic in a group of CKD patients on hemodialysis.MethodsTwenty adult hemodialysis (HD) patients (aged 54.9 ± 15.2 years) and 11 healthy individuals (aged 50.9 ± 8.0 years) were enrolled. Peripheral blood mononuclear cells (PBMC) were isolated and processed for expression of nuclear factor-κB (NF-κB), Nrf2, heme oxygenase-1 and NADPH: quinoneoxidoreductase 1 (NQO1) by quantitative real-time polymerase chain reaction and western blot analysis. Plasma malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) levels were measured.ResultsPeripheral blood mononuclear cells from HD patients had significantly lower NQO1 and Nrf2 mRNA expressions (0.58 ± 0.35 vs. 1.13 ± 0.64, p = 0.005), and significantly higher NF-κB expression (2.18 ± 0.8 vs. 1.04 ± 0.22, p = 0.0001) compared to the healthy individuals. The NF-κB expression was inversely correlated with Nrf2 levels (r = -0.54, p < 0.01) in CKD patients. Plasma MDA and TNF-α levels were significantly higher in CKD patients than in the healthy individuals.ConclusionsUp-regulation of NFκB in the CKD patients' PBMC is coupled to down-regulation of Nrf2 and NQO1 expression. These observations are consistent with recent findings in CKD animals and point to the contribution of the impaired Nrf2 system in the pathogenesis of oxidative stress and inflammation in hemodialysis patients
Glucagon induces airway smooth muscle relaxation by nitric oxide and prostaglandin E2
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Previous issue date: 2015Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Nutrição. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Inflamação. Rio de Janeiro, RJ, Brasil.Glucagon is a hyperglycemic pancreatic hormone that has been shown to provide a
beneficial effect against asthmatic bronchospasm. We investigated the role of this hormone
on airway smooth muscle contraction and lung inflammation using both in vitro and in vivo
approaches. The action of glucagon on mouse cholinergic tracheal contraction was
studied in a conventional organ bath system, and its effect on airway obstruction was also
investigated using the whole-body pletysmographic technique in mice. We also tested the
effect of glucagon on lipopolysaccharide (LPS)-induced airway hyperreactivity (AHR) and
inflammation. The expression of glucagon receptor (GcgR), CREB, phospho-CREB, nitric
oxide synthase (NOS)-3, pNOS-3 and cyclooxygenase (COX)-1 was evaluated by western blot,
while prostaglandin E2 (PGE2) and tumour necrosis factor-a were quantified by
enzyme-linked immunoassay and ELISA respectively. Glucagon partially inhibited carbacholinduced
tracheal contraction in a mechanism clearly sensitive to des-His1-[Glu9]-glucagon
amide, a GcgR antagonist. Remarkably, GcgR was more expressed in the lung and trachea
with intact epithelium than in the epithelium-denuded trachea. In addition, the
glucagon-mediated impairment of carbachol-induced contraction was prevented by either
removing epithelial cells or blocking NOS (L-NAME), COX (indomethacin) or COX-1
(SC-560). In contrast, inhibitors of either heme oxygenase or COX-2 were inactive.
Intranasal instillation of glucagon inhibited methacholine-induced airway obstruction by a
mechanism sensitive to pretreatment with L-NAME, indomethacin and SC-560.
Glucagon induced CREB and NOS-3 phosphorylation and increased PGE2 levels in the lung
tissue without altering COX-1 expression. Glucagon also inhibited LPS-induced AHR and
bronchoalveolar inflammation. These findings suggest that glucagon possesses
airway-relaxing properties that are mediated by epithelium-NOS-3-NO- and COX-1-PGE2-
dependent mechanisms
Green Tea (Camellia sinensis) Extract Induces p53-Mediated Cytotoxicity and Inhibits Migration of Breast Cancer Cells
Green tea (GT) has been shown to play an important role in cancer chemoprevention. However, the related molecular mechanisms need to be further explored, especially regarding the use of GT extract (GTE) from the food matrix. For this study, epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were identified in GTE, representing 42 and 40% of the total polyphenols, respectively. MDA-MB-231 (p53-p.R280K mutant) and MCF-7 (wild-type p53) breast tumor cells and MCF-10A non-tumoral cells were exposed to GTE for 24–48 h and cell viability was assessed in the presence of p53 inhibitor pifithrin-α. GTE selectively targeted breast tumor cells without cytotoxic effect on non-tumoral cells and p53 inhibition led to an increase in viable cells, especially in MCF-7, suggesting the involvement of p53 in GTE-induced cytotoxicity. GTE was also effective in reducing MCF-7 and MDA-MD-231 cell migration by 30 and 50%, respectively. An increment in p53 and p21 expression stimulated by GTE was observed in MCF-7, and the opposite phenomenon was found in MDA-MB-231 cells, with a redistribution of mutant-p53 from the nucleus and no differences in p21 levels. All these findings provide insights into the action of GTE and support its anticarcinogenic potential on breast tumor cells
Suppression of Hypoxia-Inducible Factor-1 alpha Contributes to the Antiangiogenic Activity of Red Propolis Polyphenols in Human Endothelial Cells
Polyphenol-enriched fractions from natural sources have been proposed to interfere with angiogenesis in pathological conditions. We recently reported that red propolis polyphenols (RPP) exert antiangiogenic activity. However, molecular mechanisms of this activity remain unclear. Here, we aimed at characterizing molecular mechanisms to explain the impact of RPP on endothelial cells' (EC) physiology. We used in vitro and ex and in vivo models to test the hypothesis that RPP inhibit angiogenesis by affecting hypoxia-inducible factor-1 alpha (HIF1 alpha) stabilization in EC. RPP (10 mg/L) affected angiogenesis by reducing migration and sprouting of EC, attenuated the formation of new blood vessels, and decreased the differentiation of embryonic stem cells into CD31-positive cells. Moreover, RPP (10 mg/L) inhibited hypoxia- or dimethyloxallylglycine-induced mRNA and protein expression of the crucial angiogenesis promoter vascular endothelial growth factor (VEGF) in a time-dependent mariner. Under hypoxic conditions, RPP at 10 mg/L, supplied for 1-4 h, decreased HIF1 alpha protein accumulation, which in turn attenuated VEGF gene expression. In addition, RPP reduced the HIF1 alpha protein half-life from similar to 58 min to 38 min under hypoxic conditions. The reduced HIF1 alpha protein half-life was associated with an increase in the von Hippel-Lindau (pVHL)-dependent proteasomal degradation of HIF1 alpha. RPP (10 mg/L, 4 h) downregulated Cdc42 protein expression. This caused a corresponding increase in pVHL protein levels and a subsequent degradation of HIF1 alpha. In summary, we have elucidated the underlying mechanism for the antiangiogenic action of RPP, which attenuates HIF1 alpha protein accumulation and signaling. J. Nutr. 142: 441-447, 2012.Deutsche Forschungsgemeinschaft [Br 999]Deutsche ForschungsgemeinschaftSander FoundationSander FoundationFoundation for Research Support of the State of Sao Paulo [08/53756-7, FAPESP-08/53755-0, DAAD-A/09/79914]Foundation for Research Support of the State of Sao Paul