Anti-obesity effects of conjugated linoleic acid, docosahexaenoic acid, and eicosapentaenoic acid
ABSTRACT Obesity has become a prevailing epidemic throughout the globe. Effective therapies for obesity become attracting. Food components with beneficial effects on "weight loss" have caught increasing attentions. Conjugated linoleic acid (CLA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) belong to different families of polyunsaturated fatty acids (PUFA). However, they have similar effects on alleviating obesity and/or preventing from obesity. They influence the balance between energy intake and expenditure; and reduce body weight and/or fat deposition in animal models, but show little effect in healthy human subjects. They inhibit key enzymes responsible for lipid synthesis, such as fatty acid synthase and stearoyl-CoA desaturase-1, enhance lipid oxidation and thermogenesis, and prevent free fatty acids from entering adipocytes for lipogenesis. PUFA also exert suppressive effects on several key factors involved in adipocyte differentiation and fat storage. Despite their similar effects and shared mechanisms, they display differences in the regulation of lipid metabolism. Moreover, DHA and EPA exhibit "anti-obesity" effect as well as improving insulin sensitivity, while CLA induces insulin resistance and fatty liver in most cases. A deeper and more detailed investigation into the complex network of anti-obesity regulatory pathways by different PUFA will improve our understanding of the mechanisms of body weight control and reduce the prevalence of obesity.
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ABSTRACT: Serum composition is linked to metabolic diseases not only to understand their pathogenesis but also for diagnostic purposes. Quality and quantity of nutritional intake can affect disease risk and serum composition. It is then possible that diet derived serum components directly affect pathogenetic mechanisms. To identify involved factors, we evaluated the effect on gene expression of direct addition of dyslipidemic human serum samples to cultured human hepatoma cells (HepG2). Sera were selected on the basis of cholesterol level, considering this parameter as mostly linked to dietary intake. Cells were treated with 32 sera from hypercholesterolemic and normocholesterolemic subjects to identify differentially regulated mRNAs using DNA microarray analysis. We identified several mRNAs with the highest modulations in cells treated with dyslipidemic sera versus cells treated with normal sera. Since the two serum groups had variable polyunsaturated fatty acids (PUFAs) contents, selected mRNAs were further assessed for their regulation by docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (AA). Four genes resulted both affected by serum composition and PUFAs: 3-hydroxy-3-methylglutaryl-CoenzymeA synthase 2 (HMGCS2), glutathione S-transferase alpha 1 (GSTA1), liver expressed antimicrobial peptide 2 (LEAP2) and apolipoprotein M (ApoM). HMGCS2 expression appears the most relevant and was also found modulated via transcription factors peroxysome proliferator activated receptor α (PPARα) and forkhead box O1 (FoxO1). Our data indicate that expression levels of the selected mRNAs, primarily of HMGCS2, could represent a reference of nutritional intake, PUFAs effects and dyslipidemic diseases pathogenesis. This article is protected by copyright. All rights reservedJournal of Cellular Physiology 01/2015; 230(9). DOI:10.1002/jcp.24932
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ABSTRACT: The significance of marine creatures as a source of unique bioactive compounds is expanding. Marine organisms constitue nearly half of the wordwide biodiversity; thus, oceans and sea present a vast resource for new substances and it is considered the largest remaining reservoir of beneficial natural molecules that maight be used as functional constituents in the food sector. This review is an update to the information about recent functional seafood compounds (proteins, peptides, amino acids, fatty acids, sterols, polysaccharides, oligosaccharides, phenolic compounds, photosynthetic pigments, vitamins, and minerals) focusing on their potential use and health benefits.Comprehensive Reviews in Food Science and Food Safety 05/2015; DOI:10.1111/1541-4337.12136