PUFA

Based on their proposed metabolic effects, we examined whether fish oil (FO) and SCFA, alone or in combination, accelerate weight loss and the resultant metabolic improvements. Obesity was induced in male C57BL/6J mice by high-energy feeding for 10 weeks. The mice were transferred to a low-fat diet (2·5w%) for 4 weeks, the source of fat being either FO, a lard-safflower oil mix (control), or both types combined with SCFA. Weight, fasting insulin, tissue and serum lipid concentrations, as well as mRNA amount of genes related to adipose inflammation and hepatic fat oxidation were determined. All groups lost weight and showed reduced fasting insulin concentrations and reduced liver TAG. However, weight loss on the control-fat diet caused significant increase in hepatic and cardiac NEFA. Substituting 20 % of the fat with SCFA increased weight loss by 48 % and reduced fasting insulin 1·5-fold more than the no-SCFA diets. It furthermore significantly increased the amount of mRNA for PPAR-α, and decreased the mRNA amount for NF-κB in the liver and white adipose tissue. The FO diets enhanced improvement of tissue lipid levels. Thus, FO improved liver TAG and NEFA levels compared with weight loss on the control diet. Combining FO and SCFA further reduced tissue NEFA accumulation. In conclusion, we found that dietary SCFA had a significant impact on gene expression in the liver and adipose tissue, and that the effect of FO on tissue NEFA content was modified by SCFA. Thus, interactions between fatty acids should be considered when studying the effects of specific fatty acids.

Dietary fatty acids have been shown to exert a clear effect on the stress response, modulating the release of cortisol. The role of fatty acids on the expression of steroidogenic genes has been described in mammals, but little is known in fish. The effect of different fatty acids on the release of cortisol and expression of stress-related genes of European sea bass (Dicentrarchus labrax) head kidney, induced by a pulse of adenocorticotrophin hormone (ACTH), was studied. Tissue was maintained in superfusion with 60 min of incubation with EPA, DHA, arachidonic acid (ARA), linoleic acid or α-linolenic acid (ALA) during 490 min. Cortisol was measured by RIA. The quantification of stress-related genes transcripts was conducted by One-Step TaqMan real-time RT-PCR. There was an effect of the type of fatty acid on the ACTH-induced release of cortisol, values from ALA treatment being elevated within all of the experimental period. The expression of some steroidogenic genes, such as the stero...

To investigate both seasonal changes and possible intracorporal gradients of phospholipid fatty acid composition, skeletal muscles (n=124), hearts (n=27), and livers (n=34) from free-living brown hares (Lepus europaeus) were analyzed. Phospholipids from both skeletal muscles and heart had a high degree of unsaturation with 66.8±0.63% and 65.7±0.5% polyunsaturated fatty acids, respectively. This is the highest proportion of polyunsaturated fatty acids reported in any mammalian tissue. Polyunsaturated fatty acid content in skeletal muscles was 2.3% greater in winter compared to summer (F 1,106=17.7; P=0.0001), which may reflect thermoregulatory adjustments. Arachidonate (C20:4n-6) showed the greatest seasonal increase (+2.5%; F=7.95; P=0.0057). However, there were no pronounced differences in polyunsaturated fatty acid content between skeletal muscles from different locations in the body (m. iliopsoas, m. longissimus dorsi and m. vastus). Total muscle phospholipid polyunsaturated fatty acid content was correlated with polyunsaturated fatty acid content in triacyglycerols from perirenal white adipose tissue depots (r 2=0.61; P=0.004). Polyunsaturated fatty acids were enriched in muscle phospholipids (56.8–73.6%), compared to white adipose tissue lipids (20.9–61.2%), and liver phospholipids (25.1–54.2%). We suggest that the high degree of muscle membrane unsaturation is related to hare-specific traits, such as a high maximum running speed.

Recent evidence has suggested that dietary polyunsaturated fatty acids (PUFAs) modulate inflammation; however, few studies have focused on the pathobiology of PUFA using isocaloric and isolipidic diets and it is unclear if the associated pathologies are due to dietary PUFA composition, lipid metabolism or obesity, as most studies compare diets fed ad libitum. Our studies used isocaloric and isolipidic liquid diets (35% of calories from fat), with differing compositions of omega (ω)-6 or long chain (Lc) ω-3 PUFA that were pair-fed and assessed hepatic pathology, inflammation and lipid metabolism. Consistent with an isocaloric, pair-fed model we observed no significant difference in diet consumption between the groups. In contrast, the body and liver weight, total lipid level and abdominal fat deposits were significantly higher in mice fed an ω-6 diet. An analysis of the fatty acid profile in plasma and liver showed that mice on the ω-6 diet had significantly more arachidonic acid (AA...

Diabetes mellitus is a multifactorial metabolic disorder caused due to deficiency of pancreatic hormone insulin, which results in failure to metabolize sugar or due to adequacy of another pancreatic hormone glucagon which results in the increased liver glucose output. Oxidative stress plays exquisite role in diabetes, which results in pathogenesis of diabetes related long term vascular complications which are the main cause of morbidity and mortality in diabetic patients. These vascular complications also result in Diabetic kidney disease (DKD) which is the single most common cause of end stage renal disease (ESRD). The present study was being aimed to evaluate the effect of fish oil on diabetic kidney damage. Diabetes was induced by repetitive intra-peritoneal injection of alloxan (100 mg/kg BW). The diabetic mice were fed the commercial pellet diet supplemented with 10% laboratory extracted fish oil of Sardinella longiceps for a period of one month. Concentration of various parameters like creatinine, uric acid, urea, protein, albumin and globulin in serum and kidney were estimated. The antioxidant parameters like vitamin C, vitamin E, GSH, SOD and Catalase, lipid peroxidation parameters like TBARS and GGT were also monitored, along with the activity of ALP and ACP. The Altered level of tissue biochemical composition and antioxidant status due to diabetes induced damages was nearly brought down to normal levels with the supplementation of 10% Sardinella fish oil.