Leucine supplementation improves adiponectin and total cholesterol concentrations despite the lack of changes in adiposity or glucose homeostasis in rats previously exposed to a high-fat diet

<p>Abstract</p> <p>Background</p> <p>Studies suggest that leucine supplementation (LS) has a therapeutic potential to prevent obesity and to promote glucose homeostasis. Furthermore, regular physical exercise is a widely accepted strategy for body weight maintenance and also for the prevention of obesity. The aim of this study was to determine the effect of chronic LS alone or combined with endurance training (ET) as potential approaches for reversing the insulin resistance and obesity induced by a high-fat diet (HFD) in rats.</p> <p>Methods</p> <p>Forty-seven rats were randomly divided into two groups. Animals were fed a control diet-low fat (<it>n = </it>10) or HFD (<it>n = </it>37). After 15 weeks on HFD, all rats received the control diet-low fat and were randomly divided according to treatment: reference (REF), LS, ET, and LS+ET (<it>n = </it>7-8 rats per group). After 6 weeks of treatment, the animals were sacrificed and body composition, fat cell volume, and serum concentrations of total cholesterol, HDL-cholesterol, triacylglycerol, glucose, adiponectin, leptin and tumor necrosis factor-alpha (TNF-α) were analyzed.</p> <p>Results</p> <p>At the end of the sixth week of treatment, there was no significant difference in body weight between the REF, LS, ET and LS+ET groups. However, ET increased lean body mass in rats (<it>P </it>= 0.019). In addition, ET was more effective than LS in reducing adiposity (<it>P </it>= 0.019), serum insulin (<it>P </it>= 0.022) and TNF-α (<it>P </it>= 0.044). Conversely, LS increased serum adiponectin (<it>P </it>= 0.021) levels and reduced serum total cholesterol concentration (<it>P </it>= 0.042).</p> <p>Conclusions</p> <p>The results showed that LS had no beneficial effects on insulin sensitivity or adiposity in previously obese rats. On the other hand, LS was effective in increasing adiponectin levels and in reducing total cholesterol concentration.</p

The in vitro and in vivo effects of yerba mate (Ilex paraguariensis) extract on adipogenesis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this study was to evaluate the effects of yerba mate extract and its principal bioactive compounds on adipogenesis. The anti-adipogenic effects of yerba mate, chlorogenic acid, quercetin and rutin were evaluated in 3T3-L1 cells using a PCR array. The results obtained in vitro were validated in vivo in a high-fat diet-induced model of obesity. The in vitro and in vivo results demonstrated that yerba mate extract down-regulated the expression of genes that regulate adipogenesis, such as Creb-1 and C/EBP alpha, and the extract up-regulated the expression of genes related to the inhibition of adipogenesis, including Dlk1, Gata2, Gata3, Klf2, Lrp5, Ppar gamma 2, Sfrp1, Tcf7l2, Wnt10b, and Wnt3a. In summary, it was demonstrated that yerba mate and its bioactive compounds regulate the expression of genes related to in vitro adipogenesis. Furthermore, yerba mate might regulate adipogenesis through the Wnt pathway. (C) 2013 Elsevier Ltd. All rights reserved.1412809815Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Modulatory effects of yerba mate (Ilex paraguariensis) on the PI3K-AKT signaling pathway

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this study was to evaluate the effects of yerba mate (YM) extract on the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway in vivo. The mice were introduced to either standard- or high-fat diet (HFD). After 8 weeks on an HFD, mice were randomly assigned to one of the two treatment conditions, water or yerba mate extract at 1.0 g/kg. After treatment, glucose blood level and hepatic insulin response were evaluated. Liver tissue was examined to determine the mRNA levels using the PI3K-AKT PCR array. The nuclear translocation of forkhead box O1 (FOXO1) was determined by an electrophoretic mobility-shift assay. Our data demonstrated that yerba mate extract significantly decreased the final body weight, glucose blood levels, and insulin resistance of mice. Molecular analysis demonstrated that an HFD downregulated Akt2, Irs1, Irs2, Pi3kca, Pi3kcg, and Pdk1; after yerba mate treatment, the levels of those genes returned to baseline. In addition, an HFD upregulated Pepck and G6pc and increased FOXO1 nuclear translocation. The intervention downregulated these genes by decreasing FOXO1 nuclear translocation. The results obtained demonstrate for the first time the specific action of yerba mate on the PI3K-AKT pathway, which contributed to the observed improvement in hepatic insulin signaling.571018821885Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Effects of a one-week treatment with acid gastric inhibitors on Helicobacter pylori-infected mice

Objective. Antiacid drugs, including omeprazole and ranitidine, were prescribed to Helicobacter pylori-infected subjects in combination with antibiotics during eradication treatment. Several reports suggest that these drugs have additional pharmacological properties, such as antineutrophil, antiapoptotic and antioxidant characteristics. The aim of this work was to study the effects of acid suppressive medication treatment in the H. pylori infection experimental model, focusing on possible additional pharmacological properties. Material and methods. The ability of gastric acid suppression was assessed in pylorus-ligated animals. Gastric H. pylori colonization levels, myeloperoxidase ( MPO) acitivity, macroscopic damage, Bax and Bcl-2 expression and DNA damage levels were assessed in C57BL/6-infected mice after treatment for one week with omeprazole ( 100 mg.kg(-1)) or ranitidine ( 100 mg.kg(-1)). Results. Omeprazole treatment increased bacteria colonization and MPO activity in mice stomachs. Both antiacid drugs efficiently improved macroscopic damage, although only omeprazole restored the expression of the antiapoptotic Bcl-2 protein in gastric mucosa of infected animals. Conclusions. Some additional omeprazole-related properties, such as antineutrophil properties, were not observed in H. pylori-infected mice after one week of treatment, suggesting that this property is restricted to in vitro approaches. However, the antiapoptotic activity of omeprazole could be attributed to an ability to modify the protein expression of Bcl-2, decreased by H. pylori infection.42121404141

Effect of mate tea (Ilex paraguariensis) supplementation on oxidative stress biomarkers and LDL oxidisability in normo- and hyperlipidaemic humans

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The effects of mate tea (MT) supplementation on LDL oxidisability and oxidative stress biomarkers in normolipidaemic and hyperlipidaemic volunteers after 60 days of ingestion were investigated. A total of 60 volunteers, of whom 18 were hyperlipidaemic and 42 were normolipidaemic, ingested 200 ml of MT (12.5 mg/ml) per day. The oxidative stress was evaluated by means of comet assay analysis, serum total antioxidant status (TAS), lipid peroxidation products evaluated by thiobarbituric acid reactive substances (TBARS) in serum, enzymatic activity of the erythrocytes Cu-Zn superoxide dismutase (Cu-Zn SOD) and glutathione peroxidase (GSH-Px), and susceptibility to copper-induced in vitro oxidation of LDL was monitored by diene conjugates. It was observed that hyperlipidaemia caused an increase in lipid peroxidation products (P < 0.001), which significantly decreased after mate tea ingestion. The serum TAS level and SOD activity were significantly increased for both groups after supplementation with MT. In addition, the susceptibility of LDL to oxidation and H2O2-induced DNA breakage after supplementation of MT for normo- and hyperlipidaemic volunteers was found to have decreased. These results show that regular ingestion of MT may improve the antioxidant capacity of body and the resistance of LDL particles to oxidation. (c) 2011 Elsevier Ltd. All rights reserved.33190197Financiadora de Estudos e Projetos (FINEP)Leao Junior S/ACoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES