Polyunsaturated fatty acids and cardiovascular disease

Replacing saturated with polyunsaturated (PUFAs) rather than monounsaturated fatty acids or carbohydrates results in cardiovascular prevention over a wide range of intakes. The mechanisms by which PUFAs reduce cardiovascular risk are manifold, and the extent and precise nature of their activities is the subject of several investigations, spanning from in vitro mechanistic studies to human intervention trials. This article reviews the most up-to-date evidence of the association between PUFA consumption and reduced cardiovascular mortality

Docosahexaenoic acid down-regulates endothelial Nox 4 through a sPLA(2) signalling pathway

We investigated the anti-inflammatory and antioxidant activities of docosahexaenoic acid (DHA) by evaluating its modulation of the two enzymes most involved in vascular inflammation, i.e. endothelial secreted phospholipase A(2) (sPLA(2)) and NADPH oxidase 4 (Nox) 4. Exposure of human aortic endothelial cells (HAECs) to DHA led to its preferential incorporation into outer leaflet phospholipids. Pre-treatment with DHA abolished HAECs stimulation induced by A23187 and Ang II, whereas the effects on IL-1 beta treatment were less pronounced. Group V sPLA2 RNA was similarly modulated by DHA supplementation. in addition, DHA decreased Nox 4 expression and activity; this effect was associated with reduced production of reactive oxygen species. Further, the use of specific inhibitors allowed demonstrating that group V sPLA2 is involved in the down-regulation of Nox 4 expression and activity by DHA. This interplay is mediated by ERK and PKC. (C) 2009 Elsevier Inc. All rights reserved

Weight and plasma lipid control by decaffeinated green tea

We investigated whether regular decaffeinated green tea intake could modulate body weight in an experimental model of obesity. Male leptin-deficient (ob/ob) mice and their C57BL/6J lean littermates (4 weeks of age; n 20/genotype) were assigned randomly to receive either decaffeinated green tea or vehicle, for 6 weeks. Body weights were recorded weekly and fluid intake was measured at each replacement. Blood was collected from the heart into collection tubes, with Li(+)-heparin as the anticoagulant. Administration of decaffeinated green tea to ob/ob mice significantly slowed their rate of weight gain, as compared with animals that were fed buffer alone. This effect is apparent after only 1 week of supplementation. No significant difference was recorded between C57BL/6J lean mice administrated decaffeinated green tea and those given buffer alone. Decaffeinated green tea consumption by ob/ob mice was also associated with significantly lower cholesterolemia, triglyceridemia, and adiponectin concentration. Fecal lipids did not change significantly throughout the experiment. In conclusion, administration of decaffeinated green tea might contribute to weight control and provides an opportunity for through-the-day consumption, without the excitatory effects of caffeine. (C) 2009 Elsevier Ltd. All rights reserved

Differential distribution of DHA-phospholipids in rat brain after feeding: A lipidomic approach

On a per-weight basis, the brain is the organ richest in lipids, including a remarkable proportion of polyunsaturated fatty acids (PUFAs) of the omega 3 series, namely eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. The cerebral effects of exogenous DHA likely depend on its degree of incorporation into neuronal phospholipids and on its distribution among the various brain structures, after intake. Hence, because PUFAs are not evenly distributed among the brain phospholipid classes and because the existence of class-specific phospholipases that regulate their turnover, we sought to investigate the incorporation of omega 3 PUFAs in selected brain areas regions and specific phospholipid classes. Rats (n=7) were administered, by oral gavage, 100 mg/kg/d of a commercially available fish oil (containing similar to 84% of long-chain omega 3 fatty acids, of which similar to 38% of DHA and similar to 46% of EPA). Control rats (n=7) received liquid paraffin. This treatment was continued for 30 days. Thereafter, we dissected three areas, namely the hippocampus, the striatum, and the cortex. Quantization of individual phospholipid classes and their molecular species was performed by ESI-MS/MS. Principal component analysis was used to examine the variation of the molecular lipid profiles (as percentage) induced by omega 3 supplementation. Our results show that provision of omega 3 fatty acids to rats results in their incorporation into brain phospholipids, the extent of which is lower in the striatum as compared with cortex and hippocampus. These data might in part explain the mixed therapeutic results obtained in neurological disorders, many of which are likely region-specific. (C) 2010 Elsevier Ltd. All rights reserved