Effects of 2 or 5 consecutive exercise days on adipocyte area and lipid parameters in Wistar rats

Background: Exercise has been prescribed in the treatment and control of dyslipidemias and cholesterolemia, however, lipid responses to different training frequencies in hypercholesterolemic men have been inconsistent. We sought to verify if different frequencies of continuous moderate exercise (2 or 5 days/week, swimming) can, after 8 weeks, promote adaptations in adipocyte area and lipid parameters, as well as body weight and relative weight of tissues in normo and hypercholesterolemic adult male rats.Methods: Normal cholesterol chow diet or cholesterol-rich diet (1% cholesterol plus 0.25% cholic acid) were freely given during 8 weeks to the rats divided in 6 experimentals groups: sedentary normal cholesterol chow diet (C); sedentary cholesterol-rich diet (H); 5x per week continuous training normal cholesterol chow diet (TC5) and cholesterol-rich diet (TH5); 2x per week continuos traning normal cholesterol chow diet (TC2) and cholesterol-rich diet (TH2).Results: No changes were observed in lipid profile in normal cholesterol chow diet, but both 2 a 5 days/week exercise improved this profile in cholesterol-rich diet. Body weight gain was lower in exercised rats. Decrease in retroperitoneal and epididymal relative weights as well as reductions in adipocyte areas under all diets types were observed only in 5 days/week, while 2 days/week showed improvements mainly in cholesterol-rich diet rats.Conclusion: Our results confirm the importance of exercise protocols to control dyslipidemias and obesity in rats. The effects of 5 days/week exercise were more pronounced compared with those of 2 consecutive days/week training.

Monosodium glutamate in standard and high-fiber diets: Metabolic syndrome and oxidative stress in rats

Objective: This study determined the effects of adding monosodium glutamate (MSG) to a standard diet and a fiber-enriched diet on glucose metabolism, lipid profile, and oxidative stress in rats. Methods: Male Wistar rats (65 ± 5 g, n = 8) were fed a standard diet (control), a standard diet supplemented with 100 g of MSG per kilogram of rat body weight, a diet rich in fiber, or a diet rich in fiber supplemented with 100 g of MSG per kilogram of body weight. After 45 d of treatment, sera were analyzed for concentrations of insulin, leptin, glucose, triacylglycerol, lipid hydroperoxide, and total antioxidant substances. A homeostasis model assessment index was estimated to characterize insulin resistance. Results: Voluntary food intake was higher and feed efficiency was lower in animals fed the standard diet supplemented with MSG than in those fed the control, fiber-enriched, or fiber- and MSG-enriched diet. The MSG group had metabolic dysfunction characterized by increased levels of glucose, triacylglycerol, insulin, leptin, and homeostasis model assessment index. The adverse effects of MSG were related to an imbalance between the oxidant and antioxidant systems. The MSG group had increased levels of lipid hydroperoxide and decreased levels of total antioxidant substances. Levels of triacylglycerol and lipid hydroperoxide were decreased in rats fed the fiber-enriched and fiber- and MSG-enriched diets, whereas levels of total antioxidant substances were increased in these animals. Conclusions: MSG added to a standard diet increased food intake. Overfeeding induced metabolic disorders associated with oxidative stress in the absence of obesity. The fiber-enriched diet prevented changes in glucose, insulin, leptin, and triacylglycerol levels that were seen in the MSG group. Because the deleterious effects of MSG, i.e., induced overfeeding, were not seen in the animals fed the fiber-enriched diets, it can be concluded that fiber supplementation is beneficial by discouraging overfeeding and improving oxidative stress that is induced by an MSG diet. © 2005 Elsevier Inc. All rights reserved.

Analysis of DNA damage induced by aflatoxin B1 in Dunkin-Hartley guinea pigs

Aflatoxin B1 (AFB1) is among the most potent naturally occurring carcinogens and classified as a group I carcinogen. Since the ingestion of aflatoxin-contaminated food is associated with several liver diseases, the aim of the present study was to evaluate the effect of 2, 20, and 200 ppb of AFB1 on DNA damage in peripheral blood lymphocytes and liver cells in Dunkin-Hartley guinea pigs. The animals were divided into four groups according to the given diet. After the treatment the lymphocytes and liver cells were isolated and DNA damage determined by Comet assay. The levels of DNA damage in lymphocytes were higher animals treated with 200 ppb of AFB1-enriched diet (P = 0.02). In the liver cells there were a relationship between the levels of DNA damage and the consumption of AFB1 in all studied groups. These results suggest that Comet assay performed on lymphocytes is a valuable genotoxic marker for high levels of exposure to AFB1 in guinea pig. Additionally our results indicate that the exposure to this toxin increases significantly and increases the level of DNA damage in liver cells, which is a key step on liver cancer development. We also suggest that the Comet assay is an useful tool for monitoring the genotoxicity of AFB1 in liver. © 2007 Springer Science+Business Media B.V.

Avaliação do efeito protetor da Euterpe oleracea (açaí) na resposta eletrofisiológica da retina de ratos expostos ao metilmercúrio

O metilmercúrio (MeHg) é a forma mais tóxica do mercúrio. A exposição ao MeHg gera estresse oxidativo, podendo afetar a retina, pois esta possui alta vulnerabilidade em função do seu elevado conteúdo de ácidos graxos poliinsaturados e consumo de oxigênio. Nesse contexto, a administração de antioxidantes exógenos obtidos pela dieta, como os presentes na Euterpe oleracea (açaí), poderia ser uma forma de prevenir esse desequilíbrio e suas consequências. Portanto, o objetivo deste trabalho foi avaliar o possível efeito protetor da Euterpe oleracea nas alterações eletrofisiológicas causadas pelo MeHg na retina. Para tal, foi realizada gavagem com MeHgCl (5 mg/Kg) ou solução salina (NaCl 0,9%) durante 7 dias e pré-tratamento com ração enriquecida com polpa de açaí (10%) por 28 dias. Foram utilizados ratos Wistar divididos em 4 grupos: Grupo MeHg (recebeu ração padrão e MeHgCl); MeHg+Açaí (ração enriquecida com açaí e MeHgCl); Açaí (ração enriquecida com açaí e NaCl); Veículo (ração padrão e NaCl). Um dia após a última gavagem os animais foram submetidos ao eletrorretinograma de campo total (ffERG) para obtenção da resposta escotópica (de bastonetes, mista 1 e mista 2) e fotópica (de cones e de flicker em 12; 18; 24 e 30Hz). No dia seguinte ao ffERG foi aplicado o teste campo aberto para avaliar a atividade locomotora dos animais. Posteriormente, foi feita medição de peroxidação lipídica no tecido retiniano pelo método TBARS. A análise estatística foi feita pelo teste ANOVA de uma via com pós-teste de Tukey, considerando significativo p<0,05. Os resultados do campo aberto e da massa corporal não apresentaram diferença entre os grupos. O MeHg reduziu a amplitude das seguintes respostas: onda-b da resposta de bastonetes (Veículo: 114,6±23,6 μV e MeHg: 41,2±9,6 μV); onda-a (Veículo: 8,4±1,4 μV e MeHg: 3,4±0,3 μV) e onda-b (Veículo: 176,7±17,8 μV e MeHg: 69,5±12,0 μV) na resposta mista 1; onda-a (Veículo: 103,1 ±23,3 μV e MeHg: 40,2±9,6 μV) e onda-b (Veículo: 281±,38,3 μV e MeHg: 138,6±14 μV) da resposta mista 2; onda-a (Veículo: 27,2 ±3,6 μV e MeHg: 7,5±1,8 μV) e onda-b (Veículo: 139,3±16,1 μV e MeHg: 54,4±10 μV) da resposta de cones; onda-b nas frequências 12 Hz (Veículo: 67,7±10μV e MeHg: 28,6±6,9 μV), 18 Hz (Veículo: 31,3±3,4 μV e MeHg: 14,2± 2,3 μV) e 24 Hz (Veículo: 21,0±1,8μV e MeHg: 11,0± 1,1μV) e 30 Hz (Veículo: 10,9±0,6μV e MeHg: 6,0± 1,1μV). O tempo implícito das ondas não foi alterado em nem uma das respostas. O pré-tratamento com Euterpe oleracea evitou a redução de amplitude de ambas as ondas nas respostas mista 1 (onda-a: 8,3±0,6 μV; onda b: 144,1±7,1 μV) e mista 2 (onda-a: 106,4±13,6μV; onda b: 275,2±27,6 μV), assim como da onda-b da resposta de cones (104,5±5,9 μV) e fotópica de flicker em 12 Hz (67,2±9,1 μV), 18 Hz (29,5±4,8 μV) e 24 Hz (21,9±2,4 μV). A peroxidação lipídica no tecido retiniano do grupo MeHg (294,9±205,8%) foi maior que a do Veículo (100±25,1%) e o açaí protegeu contra esse dano oxidativo (MeHg+Açaí: 111,2±26,1%). Nossos resultados demonstraram alteração difusa na resposta eletrofisiológica e aumento na peroxidação lipídica da retina induzidos pelo MeHg e proteção exercida pelo açaí nesses dois parâmetros. Assim, a Euterpe oleracea poderia ser utilizada como importante alternativa para amenizar as alterações causadas pelo MeHg na retina.

Partial Replacement of omega-6 Fatty Acids With Medium-Chain Triglycerides, but Not Olive Oil, Improves Colon Cytokine Response and Damage in Experimental Colitis

Background: Soybean oil is rich in omega-6 fatty acids, which are associated with higher incidence and more severe cases of inflammatory bowel diseases. The authors evaluated whether partial replacement of soybean oil by medium-chain triglycerides (MCTs) or olive oil influenced the incidence and severity of experimental ulcerative colitis by using different parenteral lipid emulsions (LEs). Methods: Wistar rats (n = 40) were randomized to receive parenteral infusion of the following LE: 100% soybean oil (SO), 50% MCT mixed with 50% soybean oil (MCT/SO), 80% olive oil mixed with 20% soybean oil (OO/SO), or saline (CC). After 72 hours of infusion, acetic acid experimental colitis was induced. After 24 hours, colon histology and cytokine expression were analyzed. Results: SO was not significantly associated with overall tissue damage. MCT/SO was not associated with necrosis (P < .005), whereas OO/SO had higher frequencies of ulcer and necrosis (P < .005). SO was associated with increased expression of interferon-gamma (P = .005) and OO/SO with increased interleukin (IL)-6 and decreased tumor necrosis factor-alpha expression (P < .05). MCT/SO appeared to decrease IL-1 (P < .05) and increase IL-4 (P < .001) expression. Conclusions: Parenteral SO with high concentration of omega-6 fatty acids was not associated with greater tissue damage in experimental colitis. SO partial replacement with MCT/SO decreased the frequency of histological necrosis and favorably modulated cytokine expression in the colon; however, replacement with OO/SO had unfavorable effects. (JPEN J Parenter Enteral Nutr. 2012; 36: 442-448)

Nötige und unnötige Behandlungen beim Hämorrhoidalleiden: Der Patient bestimmt mit

Up to one third of the general population suffers from symptoms caused by hemorrhoids. Conservative treatment comes first unless the patient presents with an acute hemorrhoidal prolapse or a thrombosis. A fiber enriched diet is the primary treatment option, recommended in the perioperative period as well as a long-term prophylaxis. A timely limited application of topical ointments or suppositories and/or flavonoids are further treatment options. When symptoms persist interventional procedures for grade I-II hemorrhoids, and surgery for grade III-IV hemorrhoids should be considered. Rubber band ligation is the interventional treatment of choice. A comparable efficacy using sclerosing or infrared therapy has not yet been demonstrated. We therefore do not recommend these treatment options for the cure of hemorrhoids. Self-treatment by anal insertion of bougies is of lowrisk and may be successful, particularly in the setting of an elevated sphincter pressure. Anal dilation, sphincterotomy, cryosurgery, bipolar diathermy, galvanic electrotherapy, and heat therapy should be regarded as obsolete given the poor or missing data reported for these methods. For a long time, the classic excisional hemorrhoidectomy was considered to be the gold standard as far as surgical procedures are concerned. Primary closure (Ferguson) seems to be superior compared to the "open" version (Milligan Morgan) with respect to postoperative pain and wound healing. The more recently proposed stapled hemorrhoidopexy (Longo) is particularly advisable for circular hemorrhoids. Compared to excisional hemorrhoidectomy the Longo-operation is associated with reduced postoperative pain, shorter operation time and hospital stay as well as a faster recovery, with the disadvantage though of a higher recurrence rate. Data from Hemorrhoidal Artery Ligation (HAL)-, if appropriate in combination with a Recto-Anal Repair (HAL/RAR)-, demonstrates a similar trend towards a better tolerance of the procedure at the expense of a higher recurrence rate. These relatively "new" procedures equally qualify for the treatment of grade III and IV hemorrhoids, and, in the case of stapled hemorrhoidopexy, may even be employed in the emergency situation of an acute anal prolapse. While under certain circumstances different treatment options are equivalent, there is a clear specificity with respect to the application of those procedures in other situations. The respective pros and cons need to be discussed separately with every patient. According to their own requirements a treatment strategy has to be defined according to their individual requirements.

High cholesterol diet and esterification of cholesterol by the intestinal mucosa of rats

Young male rats maintained on a diet containing 1% cholesterol were sacrificed at the end of 1st, 2nd, 3rd, 5th, and 7th week. Acetone powders prepared from their intestinal mucosa and pancreas were tested for the synthetic and hydrolytic activities for Vitamin A and cholesterol esters. The esterifying activity of the mucosal enzymes for both Vitamin A and cholesterol increased progressively up to the end of the 5th week; the increase in esterification of cholesterol was more marked with respect to saturated fatty acids, as compared to the unsaturated ones. The pancreatic enzymes remained unaffected. It is suggested that one of the reasons for the accumulation of cholesterol esters in animal tissues may be the increased esterification of the sterol in the mucosa induced by dietary cholesterol.

Diet rich in high glucoraphanin broccoli reduces plasma LDL cholesterol: evidence from randomised controlled trials

Cruciferous-rich diets have been associated with reduction in plasma LDL-cholesterol (LDL-C), which may be due to the action of isothiocyanates derived from glucosinolates that accumulate in these vegetables. This study tests the hypothesis that a diet rich in high glucoraphanin (HG) broccoli will reduce plasma LDL-C. METHODS AND RESULTS: One hundred and thirty volunteers were recruited to two independent double-blind, randomly allocated parallel dietary intervention studies, and were assigned to consume either 400 g standard broccoli or 400 g HG broccoli per week for 12 weeks. Plasma lipids were quantified before and after the intervention. In study 1 (37 volunteers), the HG broccoli diet reduced plasma LDL-C by 7.1% (95% CI: -1.8%, -12.3%, p = 0.011), whereas standard broccoli reduced LDL-C by 1.8% (95% CI +3.9%, -7.5%, ns). In study 2 (93 volunteers), the HG broccoli diet resulted in a reduction of 5.1% (95% CI: -2.1%, -8.1%, p = 0.001), whereas standard broccoli reduced LDL-C by 2.5% (95% CI: +0.8%, -5.7%, ns). When data from the two studies were combined the reduction in LDL-C by the HG broccoli was significantly greater than standard broccoli (p = 0.031). CONCLUSION: Evidence from two independent human studies indicates that consumption of high glucoraphanin broccoli significantly reduces plasma LDL-C

Crossover study of diets enriched with virgin olive oil, walnuts or almonds. Effects on lipids and other cardiovascular risk markers

Background and aims: Virgin olive oil (VOO) and nuts are basic components of the Mediterranean diet, a heart-healthy dietary pattern. Nuts have well known cholesterol lowering effects, while evidence is unclear for VOO. We designed a study in hypercholesterolemic patients to assess the effects on serum lipids and other intermediate markers of cardiovascular risk of replacing 40% of the fat in the background diet with VOO, walnuts or almonds. Methods and Results: After a 4 week run-in period with a healthy diet, eligible candidates were randomized into three diet sequences in a crossover design, with a common background diet enriched with VOO, walnuts or almonds, lasting 4 weeks each. Outcomes were changes of serum lipids and oxidation and inflammation markers, measured by standard methods. Plasma fatty acids were determined by gas chromatography to assess compliance. In 18 participants completing the study (9 women, mean age 56 y, BMI 25.7 kg/m(2)), LDL-cholesterol was reduced from baseline by 7.3%, 10.8% and 13.4% after the VOO, walnut and almond diets, respectively (P = 0.001, Friedman test). Total cholesterol and LDL/HDL ratios decreased in parallel. LDL-cholesterol decreases were greater than predicted from dietary fatty acid and cholesterol exchanges among diets. No changes of other lipid fractions, oxidation analytes or inflammatory biomarkers were observed. Plasma fatty acid changes after each diet sequence supported good compliance.

Increase of Cholesterol Oxidation and Decrease of PUFA as a Result of Thermal Processing and Storage in Eggs Enriched with n-3 Fatty Acids

In this work, cholesterol oxide formation and alteration of fatty acid composition were analyzed in n-3 enriched eggs under different storage periods and two temperatures. The eggs enriched with n-3 fatty acids were stored at 5 or 25 degrees C for 45 days and subsequently boiled or fried. For each treatment, 12 yolks were analyzed every 15 days including time zero. The concentrations of the cholesterol oxides 7-ketocholesterol, 7 beta-hydroxycholesterol, and 7 alpha-hydroxycholesterol increased during the storage period and were higher in fried eggs. Only the 7-ketocholesterol was affected by the storage temperature, and its concentration was highest in eggs stored at 25 degrees C. There was no significant difference in the contents of cholesterol and vitamin E at the different storage periods; however, the concentration of vitamin E decreased with thermal treatment. In addition, the n-3 polyunsaturated fatty acids, especially 18:3, 20:5, and 22:6, were reduced throughout the storage at 5 and 25 degrees C.

Intake of isoflavone-supplemented soy yogurt fermented with Enterococcus faecium lowers serum total cholesterol and non-HDL cholesterol of hypercholesterolemic rats

The aim of this study was to obtain an isoflavone-supplemented soy yogurt, fermented with Enterococcus faecium CRL 183 and Lactobacillus helveticus ssp jugurti, with suitable sensory properties and to assess the effects of the final product on blood lipids in hypercholesterolemic rats. Four isoflavone supplementation procedures were tested, in which the isoflavone was added at these stages: (1) before heat-treatment; (2) after heating and before fermentation; (3) after fermentation and (4) in the okara (by-product of soy milk) flour stirred into the fermented product when consumed. The products were subjected to a test of sensory acceptability. To assess their potential hypocholesterolemic properties in vivo, four groups of rats were used: control (C), hypercholesterolemic (H), hypercholesterolemic plus fermented product (HF) and hypercholesterolemic plus isoflavone-supplemented fermented product (HFI). Hypercholesterolemia was induced in rats of groups H, HF and HFI by feeding them on a commercial rat chow to which cholesterol and cholic acid had been added. Total, HDL and non-HDL cholesterol and triglycerides were measured in the blood of the rats. No significant sensorial differences were detected among the samples of soy yogurt supplemented with isoflavones at various processing stages. Rats fed a fermented soy product enriched with isoflavones (HFI group) had significantly (P < 0.05) less serum total cholesterol (15.5%) compared with rats fed a hypercholesterolemic diet (H group). Non-HDL cholesterol was less (P < 0.05) in rats fed a fermented soy product enriched or not with isoflavones (27.4 and 23.2%) compared to H group. The HDL-C and triglyceride concentrations did not differ significantly among the groups. It was possible to obtain an isoflavone-supplemented soy yogurt with satisfactory sensory characteristics. The resulting supplemented soy yogurt was capable of producing a lipid-lowering effect in hypercholesterolemic rats, relative to the animals that did not consume this product.

Soy beta-Conglycinin (7S Globulin) Reduces Plasma and Liver Cholesterol in Rats Fed Hypercholesterolemic Diet

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beta-Conglycinin (7S) and glycinin (11S) exert a hypocholesterolemic effect comparable to that of fenofibrate in rats fed a high-cholesterol diet

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