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Ide T. γ-Linolenic Acid-Rich Oil- and Fish Oil-Induced Alterations of Hepatic Lipogenesis, Fatty Acid Oxidation, and Adipose Tissue mRNA Expression in Obese KK-A y Mice. J Oleo Sci 2023; 72:313-327. [PMID: 36878585 DOI: 10.5650/jos.ess22341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
The physiological activity of γ-linolenic acid (GLA)-rich evening primrose oil and eicosapentaenoic and doxosahexaenoic acids-rich fish oil, which affect hepatic fatty acid oxidation and synthesis, and adipose tissue mRNA expression were compared in diabetic obese KK-A y mice. The mice were fed diets containing 100 g/kg of either palm oil (saturated fat), GLA oil, or fish oil for 21 days. These oils, compared with palm oil, greatly increased the activity and mRNA levels of hepatic fatty acid oxidation enzymes. These oils also increased the carnitine concentrations and mRNA levels of carnitine transporter (solute carrier family 22, member 5) in the liver. In general, these effects were comparable between GLA and fish oils. In contrast, GLA and fish oils, compared with palm oil, reduced the activity and mRNA levels of the proteins related to hepatic lipogenesis, except for those of malic enzyme. The reducing effect was stronger for fish oil than for GLA oil. These changes were accompanied by reductions in the triacylglycerol levels in the serum and liver. The reduction in the liver was stronger for fish oil than for GLA oil. These oils also reduced epididymal adipose tissue weight accompanied by a reduction in the mRNA levels of several proteins that regulate adipocyte functions; these effects were stronger for fish oil than for GLA oil. These oils were also effective in reducing serum glucose levels. Therefore, both fish oil and GLA-rich oil were effective at ameliorating metabolic disorders related to obesity and diabetes mellitus.
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Affiliation(s)
- Takashi Ide
- Institute of International Nutrition and Health, Jumonji University
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2
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Swarbrick MM, Cox CL, Graham JL, Knudsen LB, Stanhope K, Raun K, Havel PJ. Growth hormone treatment does not augment the anti-diabetic effects of liraglutide in UCD-T2DM rats. Endocrinol Diabetes Metab 2022; 6:e392. [PMID: 36480511 PMCID: PMC9836246 DOI: 10.1002/edm2.392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/29/2022] [Accepted: 11/02/2022] [Indexed: 12/13/2022] Open
Abstract
INTRODUCTION The incretin hormone glucagon-like peptide-1 (GLP-1) slows gastric emptying, increases satiety and enhances insulin secretion. GLP-1 receptor agonists, such as liraglutide, are used therapeutically in humans to improve glycaemic control and delay the onset of type 2 diabetes mellitus (T2DM). In UCD-T2DM rats, a model of polygenic obesity and insulin resistance, we have previously reported that daily liraglutide administration delayed diabetes onset by >4 months. Growth hormone (GH) may exert anti-diabetic effects, including increasing β-cell mass and insulin secretion, while disrupting GH signalling in mice reduces both the size and number of pancreatic islets. We therefore hypothesized that GH supplementation would augment liraglutide's anti-diabetic effects. METHODS Male UCD-T2DM rats were treated daily with GH (0.3 mg/kg) and/or liraglutide (0.2 mg/kg) from 2 months of age. Control (vehicle) and food-restricted (with food intake matched to liraglutide-treated rats) groups were also studied. The effects of treatment on diabetes onset and weight gain were assessed, as well as measures of glucose tolerance, lipids and islet morphology. RESULTS Liraglutide treatment significantly reduced food intake and body weight and improved glucose tolerance and insulin sensitivity, relative to controls. After 4.5 months, none of the liraglutide-treated rats had developed T2DM (overall p = .019). Liraglutide-treated rats also displayed lower fasting triglyceride (TG) concentrations and lower hepatic TG content, compared to control rats. Islet morphology was improved in liraglutide-treated rats, with significantly increased pancreatic insulin content (p < .05 vs. controls). Although GH treatment tended to increase body weight (and gastrocnemius muscle weight), there were no obvious effects on diabetes onset or other diabetes-related outcomes. CONCLUSION GH supplementation did not augment the anti-diabetic effects of liraglutide.
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Affiliation(s)
- Michael M. Swarbrick
- Departments of Nutrition and Department of Molecular Biosciences, School of Veterinary MedicineUniversity of California, DavisOne Shielad AvenueDavisCaliforniaUSA,Present address:
Bone Research Program, ANZAC Research InstituteThe University of SydneyConcordNew South WalesAustralia,Present address:
Concord Clinical School, Faculty of Medicine and HealthThe University of SydneyAustralia
| | - Chad L. Cox
- Departments of Nutrition and Department of Molecular Biosciences, School of Veterinary MedicineUniversity of California, DavisOne Shielad AvenueDavisCaliforniaUSA
| | - James L. Graham
- Departments of Nutrition and Department of Molecular Biosciences, School of Veterinary MedicineUniversity of California, DavisOne Shielad AvenueDavisCaliforniaUSA
| | | | - Kimber Stanhope
- Departments of Nutrition and Department of Molecular Biosciences, School of Veterinary MedicineUniversity of California, DavisOne Shielad AvenueDavisCaliforniaUSA
| | | | - Peter J. Havel
- Departments of Nutrition and Department of Molecular Biosciences, School of Veterinary MedicineUniversity of California, DavisOne Shielad AvenueDavisCaliforniaUSA
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Jacobsen BB, Leopoldo APL, Cordeiro JP, Campos DHSD, Nascimento AFD, Sugizaki MM, Cicogna AC, Padovani CR, Leopoldo AS. Cardiac, Metabolic and Molecular Profiles of Sedentary Rats in the Initial Moment of Obesity. Arq Bras Cardiol 2017; 109:432-439. [PMID: 29069204 PMCID: PMC5729779 DOI: 10.5935/abc.20170151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 04/28/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Different types of high-fat and/or high-energy diets have been used to induce obesity in rodents. However, few studies have reported on the effects observed at the initial stage of obesity induced by high-fat feeding on cardiac functional and structural remodelling. OBJECTIVE To characterize the initial moment of obesity and investigate both metabolic and cardiac parameters. In addition, the role of Ca2+ handling in short-term exposure to obesity was verified. METHODS Thirty-day-old male Wistar rats were randomized into two groups (n = 19 each): control (C; standard diet) and high-fat diet (HF, unsaturated high-fat diet). The initial moment of obesity was defined by weekly measurement of body weight (BW) complemented by adiposity index (AI). Cardiac remodelling was assessed by morphological, histological, echocardiographic and papillary muscle analysis. Ca2+ handling proteins were determined by Western Blot. RESULTS The initial moment of obesity occurred at the 3rd week. Compared with C rats, the HF rats had higher final BW (4%), body fat (20%), AI (14.5%), insulin levels (39.7%), leptin (62.4%) and low-density lipoprotein cholesterol (15.5%) but did not exhibit alterations in systolic blood pressure. Echocardiographic evaluation did not show alterations in cardiac parameters. In the HF group, muscles were observed to increase their +dT/dt (C: 52.6 ± 9.0 g/mm2/s and HF: 68.0 ± 17.0 g/mm2/s; p < 0.05). In addition, there was no changes in the cardiac expression of Ca2+ handling proteins. CONCLUSION The initial moment of obesity promotes alterations to hormonal and lipid profiles without cardiac damage or changes in Ca2+ handling.
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van Dijk G, van Heijningen S, Reijne AC, Nyakas C, van der Zee EA, Eisel ULM. Integrative neurobiology of metabolic diseases, neuroinflammation, and neurodegeneration. Front Neurosci 2015; 9:173. [PMID: 26041981 PMCID: PMC4434977 DOI: 10.3389/fnins.2015.00173] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 04/28/2015] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is a complex, multifactorial disease with a number of leading mechanisms, including neuroinflammation, processing of amyloid precursor protein (APP) to amyloid β peptide, tau protein hyperphosphorylation, relocalization, and deposition. These mechanisms are propagated by obesity, the metabolic syndrome and type-2 diabetes mellitus. Stress, sedentariness, dietary overconsumption of saturated fat and refined sugars, and circadian derangements/disturbed sleep contribute to obesity and related metabolic diseases, but also accelerate age-related damage and senescence that all feed the risk of developing AD too. The complex and interacting mechanisms are not yet completely understood and will require further analysis. Instead of investigating AD as a mono- or oligocausal disease we should address the disease by understanding the multiple underlying mechanisms and how these interact. Future research therefore might concentrate on integrating these by “systems biology” approaches, but also to regard them from an evolutionary medicine point of view. The current review addresses several of these interacting mechanisms in animal models and compares them with clinical data giving an overview about our current knowledge and puts them into an integrated framework.
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Affiliation(s)
- Gertjan van Dijk
- Department Behavioural Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Steffen van Heijningen
- Department Behavioural Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Aaffien C Reijne
- Department Behavioural Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands ; Systems Biology Centre for Energy Metabolism and Ageing, University Medical Center, University of Groningen Groningen, Netherlands
| | - Csaba Nyakas
- Department Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Eddy A van der Zee
- Department Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands
| | - Ulrich L M Eisel
- Department Molecular Neurobiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands ; University Centre of Psychiatry, University Medical Center Groningen, University of Groningen Groningen, Netherlands
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Bonafini S, Antoniazzi F, Maffeis C, Minuz P, Fava C. Beneficial effects of ω-3 PUFA in children on cardiovascular risk factors during childhood and adolescence. Prostaglandins Other Lipid Mediat 2015; 120:72-9. [PMID: 25834924 DOI: 10.1016/j.prostaglandins.2015.03.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/20/2015] [Indexed: 12/19/2022]
Abstract
Omega-3 polyunsatured fatty acids (ω-3 PUFA) are essential nutrients mainly derived from fish and seafood but present also in vegetables such as nuts and seed-oils. Some epidemiological and clinical studies indicate a protection of ω-3 FA against cardiovascular disease and a favourable effect on cardiovascular risk factors control in adults. The evidences of their effects in children and adolescents are scanty but a possible beneficial role, especially for insulin sensitivity and blood pressure control, has been proposed. In this review we want to focus especially on the evidences, which could justify the assumption of ω-3 in children and adolescents, and to underline the aspects which need further investigation. Mechanisms through which ω-3 FA act are manifolds and still a matter of investigation: beside their interaction with ion channel and their influence on plasma membrane fluidity, probably the main effect is acting as competitor for cytochrome P-450 (CYP) with respect to ω-6 FA. Thus, they can modulate the biosynthesis of eicosanoids and other lipid mediators, which likely exert a protective action. Another suggestive hypothesis is that their beneficial effect is not dependent only on the intake of ω-3 FA, but also on the complex interaction between different nutrients including ω-3 and other FAs with polymorphisms in genes involved in ω-3 FA modulation. This complex interaction has seldom been explored in children and adolescents. Further studies are needed to investigate all these points in order to find a better collocation of ω-3 FA on the available armamentarium for preventive, possibly individualized, medicine.
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Affiliation(s)
- Sara Bonafini
- Department of Medicine, University of Verona, Section of Internal Medicine C, Italy.
| | - Franco Antoniazzi
- University of Verona, Department of Life and Reproduction Science, Italy
| | - Claudio Maffeis
- University of Verona, Department of Life and Reproduction Science, Italy
| | - Pietro Minuz
- Department of Medicine, University of Verona, Section of Internal Medicine C, Italy
| | - Cristiano Fava
- Department of Medicine, University of Verona, Section of Internal Medicine C, Italy
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Tan SY, Dhillon J, Mattes RD. A review of the effects of nuts on appetite, food intake, metabolism, and body weight. Am J Clin Nutr 2014; 100 Suppl 1:412S-22S. [PMID: 24920033 DOI: 10.3945/ajcn.113.071456] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Tree nuts and peanuts are good sources of many nutrients and antioxidants, but they are also energy dense. The latter often limits intake because of concerns about their possible contribution to positive energy balance. However, evidence to date suggests that nuts are not associated with predicted weight gain. This is largely due to their high satiety value, leading to strong compensatory dietary responses, inefficiency in absorption of the energy they contain, a possible increment in resting energy expenditure, and an augmentation of fat oxidation. Preliminary evidence suggests that these properties are especially evident when they are consumed as snacks.
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Affiliation(s)
- Sze Yen Tan
- From the Department of Nutrition Science, Purdue University, West Lafayette, IN
| | - Jaapna Dhillon
- From the Department of Nutrition Science, Purdue University, West Lafayette, IN
| | - Richard D Mattes
- From the Department of Nutrition Science, Purdue University, West Lafayette, IN
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New perspectives on nutritional interventions to augment lipid utilisation during exercise. Br J Nutr 2011; 107:339-49. [PMID: 22136984 DOI: 10.1017/s0007114511006684] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The enhancement of fat oxidation during exercise is an aim for both recreational exercising individuals and endurance athletes. Nutritional status may explain a large part of the variation in maximal rates of fat oxidation during exercise. This review reveals novel insights into nutritional manipulation of substrate selection during exercise, explaining putative mechanisms of action and evaluating the current evidence. Lowering the glycaemic index of the pre-exercise meal can enhance lipid utilisation by up to 100 % through reduced insulin concentrations, although its application may be restricted to specific training sessions rather than competition. Chronic effects of dietary glycaemic index are less clear and warrant future study before firm recommendations can be made. A flurry of recent advances has overthrown the conventional view of l-carnitine supplementation, with skeletal muscle uptake possible under certain dietary conditions and providing a strategy to influence energy metabolism in an exercise intensity-dependent manner. Use of non-carbohydrate nutrients to stimulate muscle l-carnitine uptake may prove more beneficial for optimising lipid utilisation, but this requires more research. Studies investigating fish oil supplementation on fat oxidation during exercise are conflicting. In spite of some strong putative mechanisms, the only crossover trial showed no significant effect on lipid use during exercise. Ca may increase NEFA availability although it is not clear whether these effects occur. Ca and caffeine can increase NEFA availability under certain circumstances which could theoretically enhance fat oxidation, yet strong experimental evidence for this effect during exercise is lacking. Co-administration of nutrients to maximise their effectiveness needs further investigation.
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Andersen AD, Mølbak L, Thymann T, Michaelsen KF, Lauritzen L. Dietary long-chain n-3 PUFA, gut microbiota and fat mass in early postnatal piglet development--exploring a potential interplay. Prostaglandins Leukot Essent Fatty Acids 2011; 85:345-51. [PMID: 21880476 DOI: 10.1016/j.plefa.2011.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/11/2011] [Accepted: 08/12/2011] [Indexed: 12/17/2022]
Abstract
Dietary n-3PUFA and gut bacteria, particularly Bacteroidetes, have been suggested to be related to adiposity. We investigated if n-3PUFA affected fat storage and cecal bacteria in piglets. Twenty-four 4-day-old piglets were allocated to formula rich in n-3PUFA (∼3E%) from fish oil (FO) or n-6PUFA from sunflower oil (SO) for 14 days. We assessed body weight, fat accumulation by dual-energy X-ray absorptiometry and microbial molecular fingerprints. Dietary PUFA-composition was reflected in higher erythrocyte n-3PUFA in the FO- than the SO-group (P<0.001). Principal component analysis revealed group differences in the overall microbiotic composition, which involved a larger Bacteroides community in the SO-group (P=0.02). There was no significant difference in body fat percentage and no relationship between fat accumulation and gut Bacteroides. Hence, this study does not support an impact of n-3PUFA or microbiota on fat accumulation during the postnatal maturation period. The impact of dietary PUFA on the gut Bacteroides warrants further investigation.
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Affiliation(s)
- A D Andersen
- Department of Human Nutrition, Faculty of Life Sciences, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
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Andersen AD, Michaelsen KF, Hellgren LI, Trolle E, Lauritzen L. A randomized controlled intervention with fish oil versus sunflower oil from 9 to 18 months of age: exploring changes in growth and skinfold thicknesses. Pediatr Res 2011; 70:368-74. [PMID: 21691253 DOI: 10.1203/pdr.0b013e318229007b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA), from fish oil (FO), in rodents have been shown to reduce adipogenesis. Evidence of an effect on adipose tissue mass in humans is limited, and no studies have specifically aimed to elucidate this in infancy. To explore whether n-3 LCPUFA intake affects adipose tissue growth, we randomly allocated 154 healthy infants to daily supplementation with FO or sunflower oil (SO) from 9 to 18 mo of age and measured z-score changes in various anthropometric assessments of body size and skinfold thicknesses and plasma adipokine concentrations. Among the 133 completing infants, erythrocyte n-3 PUFA increased more in those receiving FO than in infants receiving SO [12.2 ± 0.7 (mean ± SE) versus 2.0 ± 0.4 fatty acid percentage (FA%), p < 0.001] with a concomitant larger decrease in n-6 PUFA (-8.9 ± 0.7 versus -0.9 ± 0.6 FA%, p < 0.001). We found no association between FO consumption relative to SO consumption and any of the anthropometric measures related to the size of the fat mass, but infants in the FO group had a lower skinfold ratio (triceps/subscapular) at 18 mo than those in SO group (p = 0.02). Our findings do not support the hypothesis that dietary n-3 LCPUFA is important for infant fat mass, but future studies testing this specifically are warranted.
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Affiliation(s)
- Anders D Andersen
- Department of Human Nutrition, University of Copenhagen, Frederiksberg C, DK-1958, Denmark
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Costa CASD, Carlos AS, Gonzalez GDPL, Reis RPG, Ribeiro MDS, dos Santos ADS, Monteiro AMV, de Moura EG, Nascimento-Saba CCAD. Diet containing low n-6/n-3 polyunsaturated fatty acids ratio, provided by canola oil, alters body composition and bone quality in young rats. Eur J Nutr 2011; 51:191-8. [DOI: 10.1007/s00394-011-0206-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 05/09/2011] [Indexed: 11/25/2022]
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Puglisi MJ, Hasty AH, Saraswathi V. The role of adipose tissue in mediating the beneficial effects of dietary fish oil. J Nutr Biochem 2010; 22:101-8. [PMID: 21145721 DOI: 10.1016/j.jnutbio.2010.07.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 04/14/2010] [Accepted: 07/28/2010] [Indexed: 12/22/2022]
Abstract
Fish oil improves several features of metabolic syndrome (MetS), such as dyslipidemia, insulin resistance and hepatic steatosis. Fish oil may mediate some of its beneficial effects by modulating the storage and/or secretory functions of adipose tissue (AT). The storage of triglycerides in AT is regulated by the availability of free fatty acids and the degree of lipolysis in AT. Fish oil has been shown to reduce lipolysis in several studies, indicating improved triglyceride storage. Importantly, AT secretes a variety of adipokines and fish oil feeding is associated with remarkable changes in the plasma levels of two key adipokines, adiponectin and leptin. Much attention has been focused on the contribution of adiponectin in fish oil-mediated improvements in MetS. However, emerging evidence also indicates a role of leptin in modulating the components of the MetS upon fish oil feeding. In addition to improving the storage and secretory functions of AT, fish oil, and the n-3 fatty acids found in fish oil, has been shown to reduce inflammation in AT. These effects may be in part a result of activation of peroxisome proliferator-activated receptor γ or inhibition of Toll-like receptor 4. Thus, there is compelling evidence that fish oil mediates its beneficial effects on MetS by improving AT storage and secretory functions and by reducing inflammation.
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Affiliation(s)
- Michael J Puglisi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232-0615, USA
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Abstract
Epidemiological studies have shown a positive relationship between dietary fat intake and obesity. Since rats and mice show a similar relationship, they are considered an appropriate model for studying dietary obesity. The present paper describes the history of using high-fat diets to induce obesity in animals, aims to clarify the consequences of changing the amount and type of dietary fats on weight gain, body composition and adipose tissue cellularity, and explores the contribution of genetics and sex, as well as the biochemical basis and the roles of hormones such as leptin, insulin and ghrelin in animal models of dietary obesity. The major factors that contribute to dietary obesity - hyperphagia, energy density and post-ingestive effects of the dietary fat - are discussed. Other factors that affect dietary obesity including feeding rhythmicity, social factors and stress are highlighted. Finally, we comment on the reversibility of high-fat diet-induced obesity.
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Tricot S, Mimouni V, Rompion S, Froger C, Lacroix P, Roux S, Ulmann L. No altered blood pressure and serum markers of oxidative stress after a long time dietary fish oil in the genetically 9 month-old type-2 diabetes Zucker rat. Prostaglandins Leukot Essent Fatty Acids 2010; 83:211-8. [PMID: 20833009 DOI: 10.1016/j.plefa.2010.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 08/04/2010] [Accepted: 08/06/2010] [Indexed: 11/20/2022]
Abstract
In this study, we investigated the effect of a high n-3 fatty acid diet (eicosapentaenoic and docosahexaenoic acids) in Zucker obese and lean rats on blood pressure in association with physiological parameters, serum biochemistry and oxidative stress analysis. After 150 days of treatment, dietary fish oil supplementation in Zucker obese rats (9 months of age) reduces bodyweight gain and serum triglyceridemia and nitrite levels, increases serum glucose and angiotensin converting enzyme activity, but does not alter blood pressure, cholesterol levels and serum markers of oxidative stress (malondialdehyde, glutathione), compared to the Zucker rats fed control diet. According to these results, we can consider that after 150 days of treatment, fish oil is not enough to regulate parameters involved in the metabolic syndrome, such as cholesterolemia and blood pressure, in a 9 month-old genetically type-2 diabetes rat.
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Affiliation(s)
- Sompadthana Tricot
- EA 2160 Mer Molécules Santé, PRES UNAM, Université du Maine, IUT de Laval, Département Génie Biologique, 52 rue des Drs Calmette et Guérin, BP 2045, 53020 Laval Cedex 9, France
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Saraswathi V, Morrow JD, Hasty AH. Dietary fish oil exerts hypolipidemic effects in lean and insulin sensitizing effects in obese LDLR-/- mice. J Nutr 2009; 139:2380-6. [PMID: 19864403 PMCID: PMC2777481 DOI: 10.3945/jn.109.111567] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Obesity is often associated with dyslipidemia, insulin resistance, and hypertension. Together, these metabolic perturbations greatly increase the risk of developing cardiovascular disease and diabetes. Although fish oil is a well-established hypolipidemic agent, the mechanisms by which it mediates its lipid-lowering effects are not clear. In addition, it has not been established whether dietary fish oil has different effects in lean and obese mice. LDL receptor deficient (LDLR-/-) and leptin deficient mice on a LDLR-/- background (ob/ob;LDLR-/-) were fed a high fat diet (39% total fat) supplemented with 6% olive oil or fish oil for 6 wk. Fish oil supplementation resulted in lower concentrations of plasma total cholesterol (P < 0.01), triglycerides (P < 0.01), and free fatty acids (P < 0.001) in lean LDLR-/- mice, but not in ob/ob;LDLR-/- mice. In contrast, a fish oil diet did not modulate insulin sensitivity in lean LDLR-/- mice, but it improved insulin sensitivity in ob/ob;LDLR-/- mice (P < 0.05) compared with olive oil fed ob/ob;LDLR-/- mice. Interestingly, plasma adiponectin concentrations were significantly higher and hepatic steatosis was reduced in both mouse models upon fish oil feeding. Finally, fish oil fed LDLR-/- mice exhibited higher hepatic AMP activated protein kinase (AMPK) phosphorylation (P < 0.05), whereas AMPK phosphorylation was not elevated by fish oil feeding in ob/ob;LDLR-/- mice. Taken together, our data suggest that fish oil reduces hepatic steatosis in both lean and obese mice, has potent plasma lipid lowering effects in lean mice, and exerts insulin sensitizing effects in obese mice.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics and Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Jason D. Morrow
- Department of Molecular Physiology and Biophysics and Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Alyssa H. Hasty
- Department of Molecular Physiology and Biophysics and Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232,To whom correspondence should be addressed.
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Park S, Park Y. Effects of dietary fish oil and trans fat on rat aorta histopathology and cardiovascular risk markers. Nutr Res Pract 2009; 3:102-7. [PMID: 20016709 PMCID: PMC2788173 DOI: 10.4162/nrp.2009.3.2.102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 04/24/2009] [Accepted: 04/30/2009] [Indexed: 11/04/2022] Open
Abstract
Fish oil and shortening have been suggested to have opposite effects on cardiovascular disease (CVD). This study investigated the effect of shortening and fish oil on CVD risk factors and aorta histopathology, and the association between risk factors and aorta histopathology. Male Wister rats (n=30) were fed an AIN-93G diet containing 20% fat in the form of fish oil, shortening, or soybean oil for 4 weeks. Total cholesterol (TC), triacylglyceride (TG), and C-reactive protein levels were significantly (P<0.001) lower in the fish oil than in soybean oil and shortening groups. HDL-cholesterol concentrations were significantly different (P<0.001) between groups. In addition, LDL-cholesterol levels were significantly (P<0.001) lower in the fish oil and shortening groups than in the soybean oil group. Insulin and glucose concentrations did not differ among groups. Effect of dietary fat on tissue fatty acid composition significantly differed in abdominal fat and brain compared with RBC, heart, kidney and liver. The aortic wall was significantly (P=0.02) thinner in the fish oil group than in the soybean oil and shortening groups. The aortic wall thickness was positively correlated with TG and TC, but negatively with EPA + DHA levels of all tissues. These results suggested that fish oil had protective effects on aorta histopathology by hypolipidemic action in this rat model.
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Affiliation(s)
- Seonhye Park
- Department of Food and Nutrition, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, Korea
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ASADI FARZAD, SHAHRIARI ALI, POURKABIR MALIHE, MACLAREN ROBIN. SHORT- AND LONG-TERM EFFECTS OF CORN OIL ON SERUM LIPID AND LIPOPROTEIN AND VISCERAL ABDOMINAL FAT PAD PARAMETERS OF RATS. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1745-4522.2007.00103.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Madsen L, Liaset B, Kristiansen K. Macronutrients and obesity: views, news and reviews. ACTA ACUST UNITED AC 2008. [DOI: 10.2217/17460875.3.1.43] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Sinitskaya N, Gourmelen S, Schuster-Klein C, Guardiola-Lemaitre B, Pévet P, Challet E. Increasing the fat-to-carbohydrate ratio in a high-fat diet prevents the development of obesity but not a prediabetic state in rats. Clin Sci (Lond) 2007; 113:417-25. [PMID: 17608620 DOI: 10.1042/cs20070182] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Metabolic disorders induced by high-fat feeding in rodents evoke some, if not all, of the features of human metabolic syndrome. The occurrence and severity of metabolic disorders, however, varies according to rodent species, and even strain, as well as the diet. Therefore, in the present study, we investigated the long-term obesogenic and diabetogenic effects of three high-fat diets differing by their fat/carbohydrate ratios. Sprague-Dawley rats were fed a control high-carbohydrate and low-fat diet [HCD; 3:16:6 ratio of fat/carbohydrate/protein; 15.48 kJ/g (3.7 kcal/g)], a high-fat and medium-carbohydrate diet [HFD1; 53:30:17 ratio of fat/carbohydrate/protein; 19.66 kJ/g (4.7 kcal/g)], a very-high-fat and low-carbohydrate diet [HFD2; 67:9:24 ratio of fat/carbohydrate/protein; 21.76 kJ/g (5.2 kcal/g)] or a very-high-fat and carbohydrate-free diet [HFD3; 75:0:25 ratio of fat/carbohydrate/protein; 24.69 kJ/g (5.9 kcal/g)] for 10 weeks. Compared with the control diet (HCD), rats fed with high-fat combined with more (HFD1) or less (HFD2) carbohydrate exhibited higher BMI (body mass index; +13 and +10% respectively; P<0.05) and abdominal fat (+70% in both HFD1 and HFD2; P<0.05), higher plasma leptin (+130 and +135% respectively; P<0.05), lower plasma adiponectin levels (-23 and -30% respectively; P<0.05) and impaired glucose tolerance. Only the HFD1 group had insulin resistance. By contrast, a very-high-fat diet devoid of carbohydrate (HFD3) led to impaired glucose tolerance, insulin resistance and hypoadiponectinaemia (-50%; P<0.05), whereas BMI, adiposity and plasma leptin did not differ from respective values in animals fed the control diet. We conclude that increasing the fat-to-carbohydrate ratio to the uppermost (i.e. carbohydrate-free) in a high-fat diet prevents the development of obesity, but not the prediabetic state (i.e. altered glucose tolerance and insulin sensitivity).
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Affiliation(s)
- Natalia Sinitskaya
- Département de Neurobiologie des Rythmes, Institut de Neurosciences Cellulaires et Intégratives, CNRS, Université Louis Pasteur, 5 rue Blaise pascal, 67084 Strasbourg, France
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Bortolotti M, Tappy L, Schneiter P. Fish oil supplementation does not alter energy efficiency in healthy males. Clin Nutr 2007; 26:225-30. [PMID: 17270317 DOI: 10.1016/j.clnu.2006.11.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Revised: 10/06/2006] [Accepted: 11/15/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND AIMS Fish oil (FO) supplementation prevents the development of obesity and insulin resistance, and upregulate the expression of UCP3 in skeletal muscle in rodents. This may represent indirect evidence that FO promotes fat oxidation and/or alter energy efficiency. The aim of this study was to evaluate whether such effects can be observed in humans. The metabolic effects of FO were assessed during exercise in order to obtain a direct measurement of energy efficiency. METHODS Eight healthy male volunteers were studied with and without supplementation with 7.2 g/day FO (including 1.1 g/day eicosopentaenoic acid and 0.7 g/day decosahexaenoic acid) during 14 days. Their VO(2 max) was measured on cycle ergometer. Thereafter, energy metabolism (substrate oxidation, energy expenditure and energy efficiency) was assessed during a 30 min cycling exercise at 50% VO(2 max) performed 2 h 30 after a standardized, high carbohydrate breakfast. RESULTS VO(2 max) was 38.6+/-2.2 after FO and 38.4+/-2.0 (mL x kg(-1) x min(-1)) in control conditions (NS). Basal plasma glucose, insulin and NEFA concentrations, and energy metabolism were similar with FO and in controls. During exercise, the increases in plasma NEFA concentrations, energy expenditure, glucose and lipid oxidation, and the decreases in glycaemia and insulinemia were not altered by FO intake. Energy efficiency was 22.4+/-0.6% after FO vs 21.8+/-0.7% in controls. In order to ascertain that the absence of effects of FO was not due to consumption of a carbohydrate meal immediately before exercise, 4 of the 8 subjects were re-studied in fasting conditions, FO also failed to alter energy efficiency in this subset of studies. CONCLUSION FO supplementation did not significantly alter energy metabolism and energy efficiency during exercise in healthy humans.
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Affiliation(s)
- Murielle Bortolotti
- Department of Physiology, University of Lausanne, 7 rue du Bugnon, 1005 Lausanne, Switzerland
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Beck B. Neuropeptide Y in normal eating and in genetic and dietary-induced obesity. Philos Trans R Soc Lond B Biol Sci 2007; 361:1159-85. [PMID: 16874931 PMCID: PMC1642692 DOI: 10.1098/rstb.2006.1855] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Neuropeptide Y (NPY) is one the most potent orexigenic peptides found in the brain. It stimulates food intake with a preferential effect on carbohydrate intake. It decreases latency to eat, increases motivation to eat and delays satiety by augmenting meal size. The effects on feeding are mediated through at least two receptors, the Y1 and Y5 receptors. The NPY system for feeding regulation is mostly located in the hypothalamus. It is formed of the arcuate nucleus (ARC), where the peptide is synthesized, and the paraventricular (PVN), dorsomedial (DMN) and ventromedial (VMN) nuclei and perifornical area where it is active. This activity is modulated by the hindbrain and limbic structures. It is dependent on energy availability, e.g. upregulation with food deprivation or restriction, and return to baseline with refeeding. It is also sensitive to diet composition with variable effects of carbohydrates and fats. Leptin signalling and glucose sensing which are directly linked to diet type are the most important factors involved in its regulation. Absence of leptin signalling in obesity models due to gene mutation either at the receptor level, as in the Zucker rat, the Koletsky rat or the db/db mouse, or at the peptide level, as in ob/ob mouse, is associated with increased mRNA abundance, peptide content and/or release in the ARC or PVN. Other genetic obesity models, such as the Otsuka-Long-Evans-Tokushima Fatty rat, the agouti mouse or the tubby mouse, are characterized by a diminution in NPY expression in the ARC nucleus and by a significant increase in the DMN. Further studies are necessary to determine the exact role of NPY in these latter models. Long-term exposure to high-fat or high-energy palatable diets leads to the development of adiposity and is associated with a decrease in hypothalamic NPY content or expression, consistent with the existence of a counter-regulatory mechanism to diminish energy intake and limit obesity development. On the other hand, an overactive NPY system (increased mRNA expression in the ARC associated with an upregulation of the receptors) is characteristic of rats or rodent strains sensitive to dietary-induced obesity. Finally, NPY appears to play an important role in body weight and feeding regulation, and while it does not constitute the only target for drug treatment of obesity, it may nevertheless provide a useful target in conjunction with others.
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Affiliation(s)
- B Beck
- Université Henri Poincaré, Neurocal, Nancy, France.
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Shirai N, Higuchi T, Suzuki H, Shimizu E. Effect of Lipids from Erabu Sea Snake, Laticauda semifasciata, on Plasma Glucose, Insulin, and Adipocytokine Concentrations of Normal and Streptozotocin-Diabetic Mice. ANNALS OF NUTRITION AND METABOLISM 2006; 50:425-32. [PMID: 16847395 DOI: 10.1159/000094634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Accepted: 02/19/2006] [Indexed: 11/19/2022]
Abstract
AIMS To clarify the influence of Erabu sea snake lipid on levels of plasma insulin and adipocyte-derived hormones. METHODS Normal male mice (6 months) and streptozotocin-diabetic mice (a single administration, 150 mg/kg i.p.) were fed diets containing 10% fat as either lard or a mixture of 5% lard and 5% sea snake lipid for 4 months. RESULTS The normal mice on the sea snake lipid diet had a significantly lower plasma glucose concentration (198 +/- 16 mg/dl; 148 +/- 11 mg/dl) than those mice on the lard diet. Although plasma insulin concentrations were not influenced by the dietary fat type, leptin (10 +/- 1 ng/ml; 16 +/- 2 ng/ml) and adiponectin (18 +/- 1 mug/ml; 21 +/- 1 mug/ml) concentrations were significantly higher in the sea snake lipid group than in the lard group. However, these effects of a sea snake lipid intake were not evident in the streptozotocin-diabetic mice. CONCLUSION The results suggest that the decrease in plasma glucose following the intake of sea snake lipids could be related to a corresponding increase in leptin and adiponectin level.
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Affiliation(s)
- Nobuya Shirai
- National Food Research Institute, Kannondai, Tsukuba, Ibaraki, Japan.
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Gossell-Williams M, Davis A, O'Connor N. Inhibition of Testosterone-Induced Hyperplasia of the Prostate of Sprague-Dawley Rats by Pumpkin Seed Oil. J Med Food 2006; 9:284-6. [PMID: 16822218 DOI: 10.1089/jmf.2006.9.284] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The oil from the pumpkin (Cucurbita pepo) seed is claimed to be useful in the management of benign prostatic hyperplasia. This investigation seeks to examine the effect of pumpkin seed oil on testosterone-induced hyperplasia of the prostate of rats. Hyperplasia was induced by subcutaneous administration of testosterone (0.3 mg/100 g of body weight) for 20 days. Simultaneous oral administration of either pumpkin seed oil (2.0 and 4.0 mg/100 g of body weight) or corn oil (vehicle) was also given for 20 days. The weights of the rats were recorded weekly, and the influence of testosterone and pumpkin seed oil on the weight gain of the rats was examined. On day 21, rats were sacrificed, and the prostate was removed, cleaned, and weighed. The prostate size ratio (prostate weight/rat body weight) was then calculated. Neither testosterone nor pumpkin seed oil had any significant influence on the weight gain of the rats. Testosterone significantly increased prostate size ratio (P < .05), and this induced increase was inhibited in rats fed with pumpkin seed oil at 2.0 mg/100 g of body weight. The protective effect of pumpkin seed oil was significant at the higher pumpkin seed oil dose (P < .02). We conclude pumpkin seed oil can inhibit testosterone-induced hyperplasia of the prostate and therefore may be beneficial in the management of benign prostatic hyperplasia.
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Affiliation(s)
- M Gossell-Williams
- Pharmacology Section, Department of Basic Medical Sciences, University of the West Indies, Jamaica.
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Wyrwoll CS, Mark PJ, Mori TA, Puddey IB, Waddell BJ. Prevention of programmed hyperleptinemia and hypertension by postnatal dietary omega-3 fatty acids. Endocrinology 2006; 147:599-606. [PMID: 16210371 DOI: 10.1210/en.2005-0748] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Fetal programming is now recognized as a key determinant of the adult phenotype, with major implications for adult-onset diseases including hypertension. Two mediators of fetal programming are maternal nutrition and fetal glucocorticoid exposure. Recent studies show that postnatal dietary manipulations can exacerbate programming effects, but whether programming effects can be attenuated by postnatal dietary manipulations, and thus provide a possible therapeutic strategy, is unknown. In this study, we tested the hypothesis that a postnatal diet enriched with long-chain omega-3 fatty acids attenuates programmed hyperleptinemia and hypertension. Pregnant rats were treated with dexamethasone (Dex) from d 13 to term, and offspring were cross-fostered to mothers on either a standard diet or a diet high in omega-3 fatty acids and remained on these diets postweaning. Maternal Dex reduced birthweight and delayed the onset of puberty in offspring. Hyperleptinemia (associated with elevated leptin mRNA expression in adipose tissue) and hypertension were evident in offspring by 6 months of age in Dex-exposed animals consuming a standard diet, but these effects were completely blocked by a high omega-3 diet. These results demonstrate for the first time that manipulation of postnatal diet can limit adverse outcomes of fetal programming, with programmed hyperleptinemia and hypertension prevented by a postnatal diet enriched with omega-3 fatty acids. This raises the possibility that dietary supplementation with omega-3 fatty acids may provide a viable therapeutic option for preventing and/or reducing adverse programming outcomes in humans.
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Affiliation(s)
- Caitlin S Wyrwoll
- School of Anatomy and Human Biology, The University of Western Australia, Nedlands, Perth, Western Australia 6009, Australia
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Madsen L, Petersen RK, Kristiansen K. Regulation of adipocyte differentiation and function by polyunsaturated fatty acids. Biochim Biophys Acta Mol Basis Dis 2005; 1740:266-86. [PMID: 15949694 DOI: 10.1016/j.bbadis.2005.03.001] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Revised: 02/23/2005] [Accepted: 03/02/2005] [Indexed: 12/11/2022]
Abstract
A diet enriched in PUFAs, in particular of the n-3 family, decreases adipose tissue mass and suppresses development of obesity in rodents. Although several nuclear hormone receptors are identified as PUFA targets, the precise molecular mechanisms underlying the effects of PUFAs still remain to be elucidated. Here we review research aimed at elucidating molecular mechanisms governing the effects of PUFAs on the differentiation and function of white fat cells. This review focuses on dietary PUFAs as signaling molecules, with special emphasis on agonistic and antagonistic effects on transcription factors currently implicated as key players in adipocyte differentiation and function, including peroxisome proliferator activated receptors (PPARs) (alpha, beta and gamma), sterol regulatory element binding proteins (SREBPs) and liver X receptors (LXRs). We review evidence that dietary n-3 PUFAs decrease adipose tissue mass and suppress the development of obesity in rodents by targeting a set of key regulatory transcription factors involved in both adipogensis and lipid homeostasis in mature adipocytes. The same set of factors are targeted by PUFAs of the n-6 family, but the cellular/physiological responses are dependent on the experimental setting as n-6 PUFAs may exert either an anti- or a proadipogenic effect. Feeding status and hormonal background may therefore be of particular importance in determining the physiological effects of PUFAs of the n-6 family.
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Affiliation(s)
- Lise Madsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
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Ide T. Interaction of fish oil and conjugated linoleic acid in affecting hepatic activity of lipogenic enzymes and gene expression in liver and adipose tissue. Diabetes 2005; 54:412-23. [PMID: 15677499 DOI: 10.2337/diabetes.54.2.412] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The interaction of dietary fish oil and conjugated linoleic acid (CLA) in affecting the activity of hepatic lipogenic enzymes and gene expression in liver and adipose tissue was examined in mice. A diet containing 1.0% CLA, mainly composed of 9cis,11trans- and 10trans,12cis-octadecadienoic acids at equivalent amounts, greatly decreased adipose tissue weight and serum concentrations of leptin and adiponectin and was accompanied by a downregulation of the expression of various adipocyte-abundant genes in epididymal adipose tissue. However, CLA increased the serum insulin concentration fourfold, and it caused hepatomegaly, with huge increases in the triacylglycerol level and the activity and mRNA levels of hepatic lipogenic enzymes. Different amounts (1.5, 3, and 6%) of fish oil added to CLA-containing diets dose-dependently downregulated parameters of lipogenesis and were accompanied by a parallel decrease in the triacylglycerol level in the liver. The supplementation of CLA-containing diets with fish oil was also associated with an increase in fat pad mass and mRNA levels of many adipocyte-abundant genes in epididymal adipose tissue along with a normalization of serum concentrations of leptin and adiponectin in a dose-dependent manner. However, in mice fed a diet containing 1.5% fish oil and CLA in whom fat pad mass was still low and comparable to that in the animals fed CLA alone, the serum insulin concentration greatly exceeded (twofold) the value observed in mice fed CLA alone, indicating an aggravation of insulin resistance. This hyperinsulinemia was ameliorated with increasing amounts of fish oil in the diets. Apparently, many of the physiological effects of CLA can be reversed by fish oil.
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Affiliation(s)
- Takashi Ide
- Laboratory of Nutritional Biochemistry, National Food Research Institute, 2-1-12 Kannondai, Tsukuba Science City 305-8642, Japan.
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Mori TA, Burke V, Puddey IB, Shaw JE, Beilin LJ. Effect of fish diets and weight loss on serum leptin concentration in overweight, treated-hypertensive subjects. J Hypertens 2004; 22:1983-90. [PMID: 15361771 DOI: 10.1097/00004872-200410000-00022] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Leptin, a circulating hormone secreted from adipocytes, is an index of adiposity and is reduced by caloric restriction and weight loss. A recent population study suggested that dietary-derived omega3 fatty acids lower leptin levels independent of body fat. OBJECTIVE To examine whether dietary fish enhanced the effects of weight loss on serum leptin levels, in 69 overweight, treated hypertensive men and women. METHODS Participants were randomized to a daily fish meal, a weight-reduction regimen, the two regimens combined or a control group for 16 weeks. RESULTS A total of 63 individuals completed the study. Weight fell 5.6 +/- 0.8 kg with energy-restriction. Blood pressure (BP) reductions in the combined fish-weight loss group were twice that seen with either intervention alone. At baseline, in all groups combined, serum leptin levels correlated with serum insulin (r = 0.307, P = 0.014), but not with body weight. The greatest change in serum leptin occurred in the fish-weight loss group (control, 0.60 +/- 0.76 ng/ml; fish, 1.20 +/- 0.79 ng/ml; weight loss, -1.40 +/- 1.05 ng/ml; fish-weight loss, -5.08 +/- 1.64 ng/ml). In the fish-weight loss group, the change in serum leptin was predicted by changes in serum insulin (r = 0.488, P = 0.038), 24-h BP (systolic BP (SBP): r = 0.435, P = 0.060; diastolic BP (DBP): r = 0.563, P = 0.018) and 24-h heart rate (0.584, P = 0.028). Using general linear models, there was a significant fish x weight-loss interaction (P = 0.008) on post-intervention serum leptin after adjustment for baseline levels, independent of post-intervention insulin. CONCLUSION A daily fish meal as part of a weight-reducing regimen was more effective than either measure alone at reducing leptin levels. Reductions in leptin may be related to the substantial fall in BP seen with the fish-weight loss program.
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Affiliation(s)
- Trevor A Mori
- School of Medicine and Pharmacology, Royal Perth Hospital Unit, University of Western, Australia.
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