Antioxidant effect of mogrosides against oxidative stress induced by palmitic acid in mouse insulinoma NIT-1 cells

Excessive oxidative stress in pancreatic β cells, caused by glucose and fatty acids, is associated with the pathogenesis of type 2 diabetes. Mogrosides have shown antioxidant and antidiabetic activities in animal models of diabetes, but the underlying mechanisms remain unclear. This study evaluated the antioxidant effect of mogrosides on insulinoma cells under oxidative stress caused by palmitic acid, and investigated the underlying molecular mechanisms. Mouse insulinoma NIT-1 cells were cultured in medium containing 0.75 mM palmitic acid, mimicking oxidative stress. The effects of 1 mM mogrosides were determined with the dichlorodihydrofluorescein diacetate assay for intracellular reactive oxygen species (ROS) and FITC-Annexin V/PI assay for cell apoptosis. Expression of glucose transporter-2 (GLUT2) and pyruvate kinase was determined by semi-quantitative reverse-transcription polymerase chain reaction. Palmitic acid significantly increased intracellular ROS concentration 2-fold (P<0.05), and decreased expression of GLUT2 (by 60%, P<0.05) and pyruvate kinase (by 80%, P<0.05) mRNAs in NIT-1 cells. Compared with palmitic acid, co-treatment with 1 mM mogrosides for 48 h significantly reduced intracellular ROS concentration and restored mRNA expression levels of GLUT2 and pyruvate kinase. However, mogrosides did not reverse palmitic acid-induced apoptosis in NIT-1 cells. Our results indicate that mogrosides might exert their antioxidant effect by reducing intracellular ROS and regulating expression of genes involved in glucose metabolism. Further research is needed to achieve a better understanding of the signaling pathway involved in the antioxidant effect of mogrosides.

Mesenteric lymph reperfusion exacerbates spleen injury caused by superior mesenteric artery occlusion shock

The intestinal lymph pathway plays an important role in the pathogenesis of organ injury following superior mesenteric artery occlusion (SMAO) shock. We hypothesized that mesenteric lymph reperfusion (MLR) is a major cause of spleen injury after SMAO shock. To test this hypothesis, SMAO shock was induced in Wistar rats by clamping the superior mesenteric artery (SMA) for 1 h, followed by reperfusion for 2 h. Similarly, MLR was performed by clamping the mesenteric lymph duct (MLD) for 1 h, followed by reperfusion for 2 h. In the MLR+SMAO group rats, both the SMA and MLD were clamped and then released for reperfusion for 2 h. SMAO shock alone elicited: 1) splenic structure injury, 2) increased levels of malondialdehyde, nitric oxide (NO), intercellular adhesion molecule-1, endotoxin, lipopolysaccharide receptor (CD14), lipopolysaccharide-binding protein, and tumor necrosis factor-α, 3) enhanced activities of NO synthase and myeloperoxidase, and 4) decreased activities of superoxide dismutase and ATPase. MLR following SMAO shock further aggravated these deleterious effects. We conclude that MLR exacerbates spleen injury caused by SMAO shock, which itself is associated with oxidative stress, excessive release of NO, recruitment of polymorphonuclear neutrophils, endotoxin translocation, and enhanced inflammatory responses.

Overexpression of myeloid differentiation protein 88 in mice induces mild cardiac dysfunction, but no deficit in heart morphology

Cardiac remodeling involves changes in heart shape, size, structure, and function after injury to the myocardium. The proinflammatory adaptor protein myeloid differentiation protein 88 (MyD88) contributes to cardiac remodeling. To investigate whether excessive MyD88 levels initiate spontaneous cardiac remodeling at the whole-organism level, we generated a transgenic MyD88 mouse model with a cardiac-specific promoter. MyD88 mice (male, 20-30 g, n=∼80) were born at the expected Mendelian ratio and demonstrated similar morphology of the heart and cardiomyocytes with that of wild-type controls. Although heart weight was unaffected, cardiac contractility of MyD88 hearts was mildly reduced, as shown by echocardiographic examination, compared with wild-type controls. Moreover, the cardiac dysfunction phenotype was associated with elevation of ANF and BNP expression. Collectively, our data provide novel evidence of the critical role of balanced MyD88 signaling in maintaining physiological function in the adult heart.

Decomposition of trimethylamine oxide related to the use of sulfites in shrimp

Currently, sulfites are employed on board to inhibit melanosis (blackspot) on crustaceans. However, when used in excess this chemical compound not only can cause adverse reactions in SO2-sensitive individuals, but also favors the decomposition of trimethylamine oxide (TMAO) into dimethylamine (DMA) and formaldehyde (FA), thus compromising the quality of the product, which can be observed mainly through the texture change of the meat after cooking. This study was conducted to verify the increase of the contents of DMA and FA by the excessive use of sodium metabisulfite in white shrimp (Penaeus schmitti). For laboratory trials, shrimp were beheaded, washed and immersed in a 2% sodium metabisulfite solution for 10 minutes. Specimens were stored either on ice and maintained for 48 hours in refrigeration, or stored in a freezer for 48 hours. Samples were collected at intervals of 0, 24 and 48 hours, and analyzed for residual SO2, TMAO, TMA, DMA and FA. The immersion of shrimp in a 2% sodium metabisulfite for 10 minutes favored the decomposition of TMAO which greatly increased the contents of DMA and FA. The FA and DMA measured in fresh shrimp was low. Moreover, the storage of shrimp tails on ice resulted in a significant reduction of the TMA, DMA, FA and residual SO2 contents compared to the specimens under frozen storage.

Enthalpy-entropy compensation based on isotherms of mango

Moisture equilibrium data of mango pulp were determined using the static gravimetric method. Adsorption and desorption isotherms were obtained in the range of 30-70 ºC, to water activities (a w) from 0.02 to 0.97. The application of the GAB model to the experimental results, using direct nonlinear regression analysis, provided agreement between experimental and calculated values. The net isosteric heat of sorption was estimated from equilibrium sorption data, using the Clausius-Clapeyron equation. Isosteric heats of sorption were found to increase with increasing temperature and could be well adjusted by an exponential relationship. The enthalpy-entropy compensation theory was applied to sorption isotherms and plots of deltaH versus deltaS provided the isokinetic temperatures, indicating an enthalpy controlled sorption process.

Effect of drying method on the adsorption isotherms and isosteric heat of passion fruit pulp powder

The sorption behavior of dry products is generally affected by the drying method. The sorption isotherms are useful to determine and compare thermodynamic properties of passion fruit pulp powder processed by different drying methods. The objective of this study is to analyze the effects of different drying methods on the sorption properties of passion fruit pulp powder. Passion fruit pulp powder was dehydrated using different dryers: vacuum, spray dryer, vibro-fluidized, and freeze dryer. The moisture equilibrium data of Passion Fruit Pulp (PFP) powders with 55% of maltodextrin (MD) were determined at 20, 30, 40 and 50 ºC. The behavior of the curves was type III, according to Brunauer's classification, and the GAB model was fitted to the experimental equilibrium data. The equilibrium moisture contents of the samples were little affected by temperature variation. The spray dryer provides a dry product with higher adsorption capacity than that of the other methods. The vibro-fluidized bed drying showed higher adsorption capacity than that of vacuum and freeze drying. The vacuum and freeze drying presented the same adsorption capacity. The isosteric heats of sorption were found to decrease with increasing moisture content. Considering the effect of drying methods, the highest isosteric heat of sorption was observed for powders produced by spray drying, whereas powders obtained by vacuum and freeze drying showed the lowest isosteric heats of sorption.

Effect of trellising system on grape and wine composition of Syrah vines grown in the cerrado region of Minas Gerais

Based on the concept that the trellising system affects not only sunlight interception and carbon assimilation, but also the fruitzone microclimate, which has a great impact on fruit composition and consequently on wine quality, the effect of two trellising systems - Vertical Shoot Position (VSP) and modified Geneva Double Curtain (GDC) - on wine and berry composition of Syrah grapes grown in João Pinheiro, Northeast region of Minas Gerais State, Brazil was investigated. The parameters such as pH, berry size and weight, and seeds total phenolic contents were not affected by the training system. The GDC system produced fruits with the highest Brix and lowest titratable acidity. Berries from the VSP system presented lower anthocyanin concentration than those from the GDC system. Similar results were found for the total phenolic content of the skin of grape berries from the VSP system. GDC wines were characterized by high anthocyanin content and red color, resulting in wines with high color intensity. These data suggest that in the tropical region of Minas Gerais state, with high temperature and high sunlight intensity, the trellising system, which protects bunches against excessive radiation, should be chosen.

Investigation of cytotoxic and mutagenic effects of Malpighia glabra L. (barbados cherry) fruit pulp and vitamin C on plant and animal test systems

Fruits are important sources of nutrients in human diet, and Barbados Cherry (Malpighia glabra L.) is of particular interest due to its high content of antioxidants. Diets rich in fruits and vegetables protect individuals against diseases and cancer, but excessive intake of vitamins may act as pro-oxidant and generate changes in DNA. To evaluate the effect of different in natura (BAN) and frozen (BAF) Barbados Cherry pulp concentrations and synthetic vitamin C in liquid form (VC) on the chromosome level and the cell cycle division, root meristeme cells of Allium cepa L. and bone marrow cells of Wistar rats Rattus norvegicus, were used as test system. In Allium cepa L., BAN, at the highest concentration (0.4 mg.mL-1) and BAF, at the lowest concentration (0.2 mg.mL-1), inhibited cell division, and there was recovery of cell division after the recovery period in water only for BAN. In the Wistar rats, all treatments with Barbados Cherry, either acute or subchronic, were not cytotoxic or mutagenic; only the highest concentration of VC increased significantly the rate of chromosomal abnormalities. The data obtained are important to reinforce the use of Barbados Cherry fruit in the diet.

Evaluation of quality factors of bovine and chicken meat marinated with reduced sodium content

In many industrialized countries, including Brazil, sodium intake exceeds the nutritional recommendations. Excessive consumption is associated with hypertension and premature death by cardiovascular diseases. The industry's challenge is to produce products with reduced sodium that are similar to regular products in texture and flavor and consistent with consumers' dietary habits. The present study aimed at substituting 25 and 50% NaCl for KCl in marinated beef and chicken meat with the addition of aromatic herbs and spices. The following microbiological analyses were carried out: macronutrient, chemical composition, and sensorial analysis. The meats showed a reduction in NaCl contents without any changes in their physical and chemical characteristics, and the products´ quality and microbiological safety were maintained. Beef and chicken tenderness was maintained for both treatments. Furthermore, the use of 50% KCl did not cause any changes in the products' sensory quality, and the overall acceptance of both types of meat was maintained. Results showed that a reduction by 50% in the NaCl contents of marinated meat products with a combination of herbs and spices is possible. Future applications in other meat products and sausages are highly promising.

Alternatives to reduce sodium in processed foods and the potential of high pressure technology

Abstract In most industrialized countries, the sodium intake exceeds the nutritional recommendations. In this sense the search for healthier foods has led the food industry to review their formulations in relation to food components such as salt, which is associated with increased risk of chronic diseases. As a result, different strategies for reducing salt levels in processed foods have been investigated. Among the technological options available, the high-pressure processing has stood out by presenting intrinsic technological advantages that can contribute to optimization of food formulations with low / reduced sodium contents. This review provides a brief overview of the key strategies and use of high pressure in the development of reduced-salt products.

Uremic pruritus in hemodialysis patients: treatment with desloratidine versus gabapentin

INTRODUCTION: Uremic pruritus is common among dialysis patients. Effective treatments are not readily available. Early evidence with antihistamines and gabapentin indicate variable effects. OBJECTIVE: To compare the efficacy and side effects of gabapentin and desloratadine in patients with dialysis pruritus. METHODS: Prospective, open-label, cross-over clinical trial in 22 patients on chronic hemodialysis with sustained pruritus over a period of at least 60 days. After a one-week run-in period, we assigned patients to three weeks of either gabapentin 300 mg thrice weekly or desloratadine 5 mg thrice weekly. After a one-week washout period, each patient crossed-over to the alternate regimen for three more weeks. The primary endpoint of the study was the change in the visual analogue pruritus score (VAS). RESULTS: Nineteen subjects completed the two treatment blocks and were available for analysis. VAS scores decreased with both treatments (5.95 to 4.6 with gabapentin, p = 0.07; 5.89 to 3.4 with desloratadine, p = 0.004), but only desloratadine reached statistical significance. There were no differences when comparing the final pruritus score with gabapentin and desloratadine (4.6 versus 3.4, p = 0.16) Excessive sedation was common with gabapentin. Desloratadine was well tolerated. CONCLUSION: Desloratadine provides significant relief of uremic pruritus compared with no therapy. gabapentin has marginal efficacy. Desloratadine is better tolerated than gabapentin.

Renegociação da dívida pública interna em condições de sobreendividamento

Renegotiation of the public debt in conditions of excessive debt. This paper studies the debt overhang models and maturity management models, and analyses both theoretically and historically the debt renegotiations which the final outcome is a lower public debt burden. From the theoretical view the renegotiation plans can be Pareto improving, both creditors and debtors can be better-off, and the value of the new debt will price the new reputation and debtors' willingness to pay. From the historical point of view, funded debts were the instrument that debtors used to improve reputation.

O milagre irlandês como exemplo da adoção de uma estratégia nacional de desenvolvimento

This paper discusses the Irish experience in the 90s, and details the main aspects of the impressive and rapid transition from a situation of excessive indebtedness, economic stagnation and high unemployment to sustainable growth. The presence of a national development strategy seems to be the crucial institutional tool that allowed this transition.

Fatores comuns determinantes de crises cambiais e financeiras

Determinative common factors of currency and financial crisis. This paper identifies and evaluates determinative common factors of currency and financial crisis in relation to 86 crises episodes between 1970-2004, based on factor analysis, cluster and discriminant analysis. One evidenced that the rise of the ratios of domestic credit, fiscal deficit and residents bank deposits to the GDP is inherent to the different types of crises classified for economic literature. It was also identified as common factors to these episodes some indicators that capture the excessive monetary expansion of the economies and that reflect the fall in international reserves, represented by M2/Reserves and Imports/Reserves ratios and also the total volume of international reserves.

Conservadorismo e rigidez na política monetária: uma estimativa da função de reação do BCB (2000-2007)

This paper aims at evaluating the conduction of monetary policy after the adoption of inflation targeting. Formation of Selic rate is modeled by estimating a reaction function of the BCB. Results show an excessive degree of interest rate smoothing and a high level of equilibrium interest rate. This evidence supports the belief that Selic rate's formation is ruled by a conservative behavior. The conservative conduction of monetary policy is related to two distinct features of BCB's reaction function: i) the great weight of autoregressive components; and, chiefly, ii) a very high level of the equilibrium interest rate. The main conclusion is that, all remaining unchanged, the interest rate would hardly be reduced in a satisfactory way. Massive and chronic deflation would be needed if Selic were to reach a reasonable level, closer to that of rates in the rest of the world. This evidences the need for a debate on the adequacy of current stabilization strategy.