716 resultados para Mild cognitive impairment, Dementia, Depression, n-3 Fatty acids, EPA, DHA
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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OBJECTIVE: the aim of this study was to determine the effects of diets rich in saturated and polyunsaturated fatty acids on metabolic pathways and the relation of metabolic shifting to oxidative stress in cardiac tissue.METHODS: Male Wistar rats (age, 60 d; n = 10) were fed with a control low-fat diet, a diet rich in saturated fatty acids (SFAs), or a diet rich in polyunsaturated fatty acids (PUFAs). After 5 wk of treatment, sera were used for protein and lipid determinations. Protein, glycogen, triacylglycerol, lactate dehydrogenase, citrate synthase, beta-hydroxyacyl coenzyme-A dehydrogenase, catalase, glutathione peroxidase, superoxide dismutase, lipoperoxide, and lipid hydroperoxide were measured in cardiac tissue.RESULTS: the SFA group had higher triacylglycerol, cholesterol, low-density lipoprotein cholesterol, and atherogenic index (ratio of cholesterol to high-density lipoprotein) than did the PUFA and control groups. The PUFA group had low serum cholesterol, triacylglycerol, and low-density lipoprotein cholesterol as compared with the SFA group. SFA increased myocardial lipid hydroperoxide and diminished glutathione peroxidase. Despite the beneficial effects on serum lipids, the PUFA diet led to the highest levels of myocardial lipoperoxide and lipid hydroperoxide and diminished superoxide dismutase and catalase activities. The PUFA effects were related to increased feed efficiency, increased susceptibility to lipoperoxidation, and metabolic shifting in cardiac tissue. PUFA elevated triacylglycerol levels and decreased myocardial glycogen concentrations. The ratios of lactate dehydrogenase to citrate synthase and beta-hydroxyacyl coenzyme-A dehydrogenase to citrate synthase were increased, indicating myocardial reduction of tricarboxylic acid cycle.CONCLUSIONS: PUFAs have been recommended as a therapeutic measure in preventive medicine to lower serum cholesterol, but PUFAs increased oxidative stress in the heart by providing cardiac susceptibility to lipoperoxidation and shifting the metabolic pathway for energy production. The control diet, which was much lower in calories and fat, produced better overall clinical outcomes, better fat profiles, and less oxidative stress than did the diets rich in fatty acids.
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These experiments were carried out to study the effects of acute cold exposure (0-2°C/4 hr) on rectal temperature, blood glucose and plasma free fatty acids (FFA) in alloxan-diabetic rats. Male Wistar rats weighing 170-190 g were used and diabetes was induced by i.v. alloxan injection (40 mg/kg body wt). Cold exposure produced severe hypothermia in diabetic rats. After 4 hr of cold, blood glucose of diabetic rats was reduced from 296±16 to 86t±12 mg/dl (P<0.01), and FFA increased slightly, but was not statistically different (P>0.05) from the initial value. As expected, interscapular brown adipose tissue (IBAT) and retroperitoneal and epididymal white adipose tissues were significantly lower in diabetic than in control rats. Cold exposure reduced total IBAT lipids in control but not in diabetic animals. The results of this experiment suggest that diabetic rats were unable to maintain body temperature in the cold, probably because of a failure to generate an adequate amount of heat by nonshivering thermogenesis in brown adipose tissue.
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The inhibitory effect of leaves extracts of Carnavalia ensiformis on the development of the symbiotic fungus of the leaf-cutting ants Atta sexdens (Forel) was evaluated. The hexane extract showed highest activity at concentration of 1000 μg/mL. Chromatographic separations of this extract have led to the isolation of a mixture of fatty acids which showed the same activity of the crude extract.
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Purpose: The purpose of this paper is to characterize oils extracted from Bertholletia excelsa, Lecythis pisonis, Dipteryx lacunifera, Carya illinoensis and Juglans regia, regarding their characterization and fatty acid profile. Design/methodology/approach: The oils were extracted from oilseeds by cold pressing and physico-chemical characterization was performed by using standard methods for oils and fats. The oxidative stability and fatty acid profile also were determined. Findings: According to the results, the physico-chemical properties of oils from nuts and walnuts were comparable to those of good quality conventional oils. The oil seeds are a good source of unsaturated fatty acids, especially oleic and linoleic acids. Research limitations/implications: Implies the identification of fatty acid profile and physico-chemical properties of oils extracted from nuts and walnuts, and to prevent certain types of diseases. Originality/value: The paper identifies a new source of essential fatty acids extracted from oilseeds. © Emerald Group Publishing Limited.
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The present work aimed to quantify the fatty acids in total lipids of Nile tilapia fingerlings (Oreochromis niloticus) fed with different sources of vegetable oils mechanically extracted. Were used 320 tilapias (O. niloticus) with average initial weight and average total initial length of 2.55±0.57 g and 5.59±0.43 cm, respectively, fed for a period of 60 days, in a randomized block design with eight treatments and four replications. The diets were prepared with 320 g/kg crude protein and 3.500 kcal of digestible energy per kg of feed enriched with eight different oils: sunflower, canola, sesame, linseed, peanut, Para's nut soy and macadamia, with an addition of 4%. Among the major fatty acids the oleic, palmitic, linolenic and linoleic were obtained in higher concentration (mg/g of LT) in fish from all treatments. The sums of polyunsaturated fatty acids after 60 days of cultivation had increased in all treatments compared to the 30 days of the experiment. This is due to the addition of oils with high contents of n-6 and n-3 fatty acids. The fatty acids in the carcass are a reflection of the energy source of oil used. As a conclusion it is recommended the use of linseed oil in the diet of tilapia fingerlings due to great improvement in the relationship between n-6/n-3.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)