Browsing by Subject "Fish oil"

Now showing 1 - 3 of 3
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    Comparative study of the modulation of fructose/sucrose-induced hepatic steatosis by mixed lipid formulations varying in unsaturated fatty acid content
    (Springer (Biomed Central Ltd.), 2015) Siddiqui, Rafat A.; Xu, Zhidong; Harvey, Kevin A.; Pavlina, Thomas M.; Becker, Michael J.; Zaloga, Gary P.; Department of Medicine, IU School of Medicine
    BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in developed countries. NAFLD encompasses a spectrum of diseases, ranging from hepatic steatosis to non-alcoholic steatohepatitis (NASH), cirrhosis, and liver failure. The etiology of NAFLD remains unclear but is thought to relate to increased fatty acid flux within the liver that results in toxic fatty acid metabolite production. One source of increased fatty acid flux is fructose/sucrose-induced hepatic lipogenesis. Current treatment for NAFLD encompasses dietary modifications. However, little scientific evidence exists on which to base many dietary recommendations, especially the intake of different types of carbohydrates and fats. We hypothesized that lipid mixtures of unsaturated fatty acids would inhibit lipogenesis and subsequent hepatic steatosis induced by high carbohydrate diets. The aim of this study was to examine the effects of different complex mixtures of fatty acids upon the development of fructose/sucrose-induced hepatic steatosis. METHODS: C57BL/6 mice were randomized to normocaloric chow-based diets that varied in the type of carbohydrate (starch, sucrose, fructose). Animals in each carbohydrate group were further randomized to diets that varied in lipid type (no additional lipid, soybean oil, fish oil, olive/soybean oil, macadamia nut oil). These oils were chosen based upon their content of omega-6 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, omega-9 monounsaturated fatty acids, or omega-7 monounsaturated fatty acids. Fatty acid flux in the liver was determine by assessing hepatic lipid content (steatosis). We also assessed fatty acid levels in the plasma and liver of the animals, hepatic lipogenesis activity, hepatic stearoyl-CoA-1 desaturase activity, and hepatic elongase activity. RESULTS: Animals consumed similar amounts of the diets and maintained normal body weights throughout the study. Both sucrose and fructose induced hepatic lipogenesis and steatosis, with fructose being more potent. All mixed lipids similarly inhibited steatosis, limiting lipid content to levels found in the control (starch) animals. Lipogenesis and stearoyl-CoA-1 desaturase activity were increased in the sucrose and fructose groups. Levels of these enzymatic processes remained at baseline in all of the lipid groups. CONCLUSION: This is the first study to compare various complex lipid mixtures, based upon dietary oils with different types of long-chain fatty acids, upon development of sucrose/fructose-induced steatosis. Both carbohydrate source and lipid content appear important for the modulation of steatosis. Moderate intake of complex lipids with high unsaturated to saturated fatty acid ratios inhibited both lipogenesis and steatosis.
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    The effects of dietary polyunsaturated fatty acids on prostate cancer-proteomic and phosphoproteomic studies
    (2016-05) Zhao, Heng; Wang, Mu
    This dissertation studies the effects of fatty acids on prostate cancer. Prostate cancer is one of the most common malignant diseases in males in the U.S. Because of the slow progression of this disease, early intervention methods, especially, dietary fatty acid interventions are considered very important to control the disease in early stages. This study describes how the depletion of the enzyme for endogenous fatty acid synthesis, fatty acid synthase, influences the expression of enzymes that metabolize dietary fatty acids and show how dietary fatty acids affect prostate cancer protein expression and function. Fatty acid synthase is an oncoprotein overexpressed in prostate cancer and its expression is suppressed with omega-3 fatty acid treatment. This study finds that the depletion of fatty acid synthase by siRNA knockdown induces suppression of cyclooxygenase-2 and fatty acid desaturase-1. Our results also show that fish oil (omega-3 fatty acid), but not oleic acid (omega-9 fatty acid), suppresses prostate cancer cell viability. Assessment of fatty acid synthesis activity indicates that oleic acid is a more potent inhibitor than fish oil of de novo fatty acid biosynthesis. In addition, the inhibition of its activity occurs over several days while its effects on cell viability occur within 24 hours. To better understand this relationship, label free LC-MS/MS based mass spectrometry was carried out to determine global proteomic and phosphoproteomic profiles of the prostate cell line PC3, with longitudinal treatment with fish oil or oleic acid. With short-term fish oil treatment, sequestosome-1was elevated. Prolonged treatment induced downregulation of microseminoprotein, a proinflammation factor, as well as proteins in the glycolysis pathway. In the phosphoproteomics study, we confidently identified 828 phosphopeptides from 361 phosphoproteins. Quantitative comparison between fish oil or oleic acid treated groups and the untreated group suggests that the fish oil induces changes in phosphorylation of proteins involved in the pathways associated with cell viability and metabolic processes, with fish oil inducing significant decreases in the levels of phospho-PDHA1Ser232 and phospho-PDHA1Ser300 and they were accompanied by an increase in PDH activity, suggesting a role for n-3 polyunsaturated fatty acids in controlling the balance between lipid and glucose oxidation.
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    Erythrocyte Long-Chain ω-3 Fatty Acids Are Positively Associated with Lean Mass and Grip Strength in Women with Recent Diagnoses of Breast Cancer
    (Elsevier, 2021) Belury, Martha A.; Cole, Rachel M.; Andridge, Rebecca; Keiter, Ashleigh; Raman, Subha V.; Lustberg, Maryam B.; Kiecolt-Glaser, Janice K.; Medicine, School of Medicine
    Background: Sarcopenia may hasten the risk of mortality in women with breast cancer. Long-chain omega-3 (n-3) polyunsaturated fatty acids (LCn-3PUFAs) may favor muscle mass which, in turn, could enhance resilience of cancer patients toward cancer treatment. Objectives: The objective of this study was to measure the relation of erythrocyte LCn-3PUFA concentrations with lean mass, grip strength, and postprandial energy metabolism in women with newly diagnosed breast cancer. Methods: This cross-sectional analysis evaluated women (n = 150) ages 65 y and younger who were recently diagnosed with breast cancer (stages I-III). Erythrocyte LCn-3PUFA composition was measured using GC. Body composition was measured by DXA. Grip strength was assessed at the same visit. Postprandial energy metabolism was measured for 7.5 h after the consumption of a high-calorie, high-saturated-fat test meal using indirect calorimetry. Associations of fatty acids with outcomes were analyzed using multiple linear regression models and linear mixed-effects models. Results: The ω-3 index, a measurement of LCn-3PUFA status, was positively associated with appendicular lean mass (ALM)/BMI (β = 0.015, P = 0.01) and grip strength (β = 0.757, P = 0.04) after adjusting data for age and cancer stage. However, when cardiorespiratory fitness was also included in the analyses, these relations were no longer significant (P > 0.08). After a test meal, a higher ω-3 index was associated with a less steep rise in fat oxidation (P = 0.02) and a steeper decline in glucose (P = 0.01) when adjusting for age, BMI, cancer stage, and cardiorespiratory fitness. Conclusions: The ω-3 index was positively associated with ALM/BMI and grip strength in women newly diagnosed with breast cancer and was associated with altered postprandial substrate metabolism. These findings warrant further studies to determine whether enriching the diet with LCn-3PUFAs during and after cancer treatments is causally linked with better muscle health and metabolic outcomes in breast cancer survivors.