Mechanism of the antithrombotic effect of dietary diacylglycerol in atherogenic mice.
ABSTRACT We have shown earlier that diacylglycerol (DAG) but not triacylglycerol (TAG) inhibited thrombus formation. The aim of the present study was to investigate the mechanism of this antithrombotic effect of DAG.
Four different diets, the (1) Western-style high-fat diet (HFD) containing 20% lipid and 0.05% cholesterol (w/w), (2) TAG-rich and (3) DAG-rich HFDs containing 20% lipid and 0.05% cholesterol, but all lipid replaced by TAG or DAG oil with very similar fatty acid composition and the (4) Japanese-style low-fat diet (LFD) containing 7% oil but no cholesterol were given to apolipoprotein E and low-density lipoprotein (LDL) receptor double-deficient mice. Atherogenicity was assessed by morphology, mapping the whole aorta and measuring the total area of lipid-stained lesions. Endothelial function was measured by the flow-mediated vasodilation test. Platelet reactivity was assessed from native blood sample by a shear-induced platelet function test (hemostatometry). Serum lipoprotein profile was measured by HPLC.
Both the Western-style and the TAG-rich HFDs have accelerated atherosclerosis. In contrast, DAG-rich HFD inhibited the atherosclerotic process to an extent comparable with the Japanese-style LFD. There was no significant difference in platelet and coagulant activity between the studied diet groups. DAG-rich but not the TAG-rich HFD significantly suppressed serum LDL cholesterol level.
The present findings suggest that the mechanism of antithrombotic and anti-atherogenic effect of DAG may involve the protection of the vascular endothelium from injury and lowered serum LDL cholesterol.
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ABSTRACT: Diacylglycerol (DAG) may undergo differential metabolism compared with triacylglycerol (TAG) in humans, possibly resulting in decreased serum TAG concentration and TAG synthesis and increased energy expenditure (EE), thus reducing fat accumulation. Our objective was to examine the efficacy of DAG oil (Enova oil) consumption on serum lipid profiles, hepatic lipogenesis, EE, and body weight and composition compared with a control oil-blend composed of sunflower, safflower, and rapeseed oils at a 1:1:1 ratio. Twenty-six overweight (78.3 +/- 3.6 kg body weight and BMI 30.0 +/- 0.7 kg/m(2)) mildly hypertriglyceridemic (1.81 +/- 0.66 mmol/L) women underwent 2 treatment phases of 28 d separated by a 4-wk washout period using a randomized crossover design. They consumed 40 g/d of either DAG or control oil during treatment phases. The baseline, EE, fat oxidation, body composition, and lipid profiles did not differ between the DAG and control oil intervention periods. Relative to control oil, DAG oil did not alter endpoint postprandial EE, fat oxidation, serum lipid profiles, or hepatic lipogenesis. However, DAG oil consumption reduced (P < 0.05) accumulation of body fat within trunk, android, and gynoid regions at the endpoint compared with control oil, although neither DAG nor control oil altered any of these variables during the 4-wk intervention period compared with their respective baseline levels. We conclude that although DAG oil is not effective in lowing serum lipids over a 4-wk intervention, it may be useful for reducing adiposity.Journal of Nutrition 06/2010; 140(6):1122-6. · 4.20 Impact Factor
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ABSTRACT: The metabolic syndrome is a cluster of metabolic disorders, such as abdominal obesity, dyslipidemia, hypertension and impaired fasting glucose that contribute to increased cardiovascular morbidity and mortality. Although the pathogenesis of metabolic syndrome is complicated and the precise mechanisms have not been elucidated, dietary lipids have been recognized as contributory factors in the development and the prevention of cardiovascular risk clustering. This review explores the physiological functions and molecular actions of bioactive lipids, such as n-3 polyunsaturated fatty acids, conjugated fatty acids, sterols, medium-chain fatty acids, diacylglycerols and phospholipids, in the development of metabolic syndrome. Dietary bioactive lipids suppress the accumulation of abdominal adipose tissue and lipids in the liver and serum, and alleviate hypertension and type 2 diabetes through the transcriptional regulation of lipid and glucose metabolism. Peroxisome proliferator-activated receptors (PPARs), sterol regulatory element binding proteins, liver X receptor alpha, retinoid X receptor alpha, farnesoid X receptor alpha, hepatic nuclear factor 4alpha and nuclear factor kappaB contribute to these nuclear actions of bioactive lipids with complex interactions. Recent studies have demonstrated the striking ability of bioactive lipids to regulate the production of physiologically active adipocytokines through PPARgamma activation. In particular, the function of bioactive lipids as dietary adiponectin inducers (dietary insulin sensitizers) deserves attention with respect to alleviation of metabolic syndrome by dietary manipulation.Progress in Lipid Research 04/2008; 47(2):127-46. · 10.25 Impact Factor