2-OHOA supplementation reduced adiposity and improved cardiometabolic risk to a greater extent than n-3 PUFA in obese mice.

OBJECTIVE: We aimed to assess whether 2-hydroxyoleic acid (2-OHOA) and n-3 polyunsaturated fatty acids (PUFA) could counteract changes on adipokine secretion and cardiometabolic risk biomarkers associated with high-fat diet-induced obesity in mice. METHODS: Female ICR/CD1 mice (8 weeks old) were divided into four groups receiving different diets (n=8/group): (1) standard chow (control) for 18 weeks; (2) 22% fat for 4 weeks + 60% fat for 14 weeks (obesogenic diet, OD); 3) OD + 2-OHOA (1500mgkg-1 diet) for the last 6 weeks (ODHO); and 4) OD+n-3 PUFA (eicosapentaenoic+docosahexaenoic acids, 1500+1500mgkg-1 diet) for the last 6 weeks (OD-N3). After 18 weeks, body weight, periovarian visceral fat, heart and liver weights were measured, as well as cardiometabolic parameters (systolic and diastolic blood pressure, blood glucose, insulin, HOMA index, triglycerides, total cholesterol, apolipoproteins A1 and E), plasma adipokines and inflammatory proteins (leptin, adiponectin, plasminogen activator inhibitor 1 [PAI1], soluble E-selectin [sE-selectin], matrix metalloproteinase-9 [MMP-9], fibrinogen, soluble intercellular adhesion molecule [sICAM] and soluble vascular adhesion molecule [sVCAM]), and secretion of pro-inflamatory cytokines and inflammatory biomarkers from periovarian adipocytes. RESULTS: OD mice had greater body and heart weights, and plasma leptin, and lower adiponectin and resistin secretion from adipocytes. Supplementation with 2-OHOA reduced body and heart weights, blood pressure, triglycerides and leptin, and restored adiponectin and resistin secretion, while n-3 PUFA only reduced triglyceride levels (all P<0.05). CONCLUSION: 2-OHOA supplementation was more effective in reducing adiposity, modulating adipokine secretion and ameliorating cardiometabolic risk than n-3 PUFA.

Immune dysfunction and increased oxidative stress state in diet-induced obese mice are reverted by nutritional supplementation with monounsaturated and n-3 polyunsaturated fatty acids.

PURPOSE: Obesity is associated with impaired immune defences and chronic low levels of inflammation and oxidation. In addition, this condition may lead to premature aging. The aim of the study was to evaluate the effects of a nutritional supplementation with monounsaturated and n-3 polyunsaturated fatty acids on several functions and oxidative stress parameters in peritoneal immune cells of obese mice, as well as on the life span of these animals. METHODS: Obesity was induced in adult female ICR/CD1 by the administration of a high-fat diet (HFD) for 14 weeks. During the last 6 weeks of HFD feeding, one group of obese mice received the same HFD, supplemented with 1500 mg of 2-hydroxyoleic acid (2-OHOA) and another with 3000 mg of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Several functions and oxidative stress parameters of peritoneal leukocytes were evaluated. RESULTS: The groups of obese mice treated with 2-OHOA or with EPA and DHA showed a significant improvement in several functions such as chemotaxis, phagocytosis, digestion capacity, Natural killer activity and lymphoproliferation in response to mitogens. All of these functions, which were decreased in obese mice, increased reaching similar levels to those found in non-obese controls. Both treatments also improved oxidative stress parameters such as xanthine oxidase activity, which decreased, catalase activity and glutathione levels, which increased. CONCLUSION: These data suggest that dietary supplementation with monounsaturated and n-3 polyunsaturated fatty acids could be an effective nutritional intervention to restore the immune response and oxidative stress state, which are impaired in obese mice.

Oxidative stress and immunosenescence in spleen of obese mice can be reversed by 2-hydroxyoleic acid.

NEW FINDINGS: What is the central question of this study? Evidence is growing for the link between obesity, immune dysfunction and oxidative stress, but it is still not known how the properties and functions of the spleen and splenic leucocytes are affected. What is the main finding and its importance? Obesity led to premature immunosenescence, manifested as oxidative stress and changes in leucocyte functions in mouse spleen. The oleic acid derivative 2-hydroxyoleate and, to a lesser extent, a combination of eicosapentaenoic and docosahexaenoic acids could reverse most of the observed alterations, suggesting a potential therapeutic tool for obesity-related immune dysfunction and redox imbalance. We aimed to investigate the effects of obesity on oxidative stress and leucocyte function in the mouse spleen and to assess whether supplementation with 2-hydroxyoleic acid (2-OHOA) or n-3 polyunsaturated fatty acids (PUFAs) could reverse those effects. Female ICR/CD1 mice (8 weeks old, n = 24) received an obesogenic diet (22% fat for 4 weeks and 60% fat for 14 weeks). After 6 weeks, mice were divided into the following three groups (n = 8 per group): no supplementation; 2-OHOA supplementation (1500 mg kg-1 of diet); and n-3 PUFA supplementation (eicosapentaenoic acid and docosahexaenoic acid, 1500 + 1500 mg kg-1 of diet). Eight mice were fed the standard diet for the whole duration of the study (control group). At the end of the experiment, the following variables were assessed in spleens: levels of reduced (GSH) and oxidized glutathione (GSSG), GSH/GSSG, xanthine oxidase activity, lipid peroxidation, lymphocyte chemotaxis, natural killer activity and mitogen (concanavalin A and lipopolysaccharide)-induced lymphocyte proliferation. Obese animals presented higher GSSG levels (P = 0.003), GSSG/GSH ratio (P = 0.013), lipid peroxidation (P = 0.004), xanthine oxidase activity (P = 0.015) and lymphocyte chemotaxis (P < 0.001), and lower natural killer activity (P = 0.003) and proliferation in response to concanavalin A (P < 0.001) than control mice. 2-Hydroxyoleic acid totally or partly reversed most of the changes (body weight, fat content, GSSG levels, GSH/GSSG, lipid peroxidation, chemotaxis and proliferation, all P < 0.05), whereas n-3 PUFAs reversed the increase in xanthine oxidase activity (P = 0.032). In conclusion, 2-OHOA or, to a lesser extent, n-3 PUFAs could ameliorate the oxidative stress and alteration of leucocyte function in the spleens of obese mice. Our findings support a link between obesity and immunosenescence and suggest a potential therapeutic tool for obesity-related immune dysfunction.

Changes in gut microbiota due to supplemented fatty acids in diet-induced obese mice.

Consumption of a high-fat diet (HFD), which is associated with chronic 'low-grade' systemic inflammation, alters the gut microbiota (GM). The aim of the present study was to investigate the ability of an oleic acid-derived compound (S1) and a combination of n-3 fatty acids (EPA and DHA, S2) to modulate both body weight and the GM in HFD-induced obese mice. A total of eighty mice were fed either a control diet or a HFD, non-supplemented or supplemented with S1 or S2. At week 19, faeces were collected in order to analyse the GM. Group-specific primers for accurate quantification of several major bacterial groups from faecal samples were assayed using quantitative PCR. The HFD induced an increase in body weight, which was reduced by supplementation with S1. Furthermore, S1 supplementation markedly increased total bacterial density and restored the proportions of bacteria that were increased (i.e. clostridial cluster XIVa and Enterobacteriales) or decreased (i.e. Bifidobacterium spp.) during HFD feeding. S2 supplementation significantly increased the quantities of Firmicutes (especially the Lactobacillus group). Correlation analysis revealed that body weight correlated positively with the phylum Firmicutes and clostridial cluster XIVa, and negatively with the phylum Bacteroidetes. In conclusion, the consumption of a HFD induced changes in the faecal microbiota, which were associated with the appearance of an obese phenotype. Supplementation of the HFD with S1 counteracted HFD-induced gut dysbiosis, together with an improvement in body weight. These data support a role for certain fatty acids as interesting nutrients related to obesity prevention.