The role of Odontella aurita, a marine diatom rich in EPA, as a dietary supplement in dyslipidemia, platelet function and oxidative stress in high-fat fed rats

Adil Haimeur,Lionel Ulmann,Gérard Tremblin,Fabienne Pineau-Vincent,Frédérique Guéno,Nadia Meskini,Virginie Mimouni

doi:10.1186/1476-511x-11-147

Abstract

BackgroundDietary changes are a major factor in determining cardiovascular risk. n-3 polyunsaturated fatty acids modulate the risk factors for metabolic syndrome via multiple mechanisms, including the regulation of the lipid metabolism. We therefore investigated the effect of Odontella aurita, a microalga rich in EPA, which is already used as a food supplement, on the risk factors for high-fat diet induced metabolic syndrome in rats.MethodsMale Wistar rats were divided into 4 groups and were fed with a standard diet (control); with the standard diet supplemented with 3% freeze-dried O. aurita (COA); with a high-fat diet (HF); or with the high-fat diet supplemented with 3% of freeze-dried O. aurita (HFOA) for 7 weeks. In this study we evaluated the impact of these different diets on the risk factors for metabolic syndrome, such as hyperlipidemia, platelet aggregation, thromboxane B2 production, and oxidative stress.ResultsAfter 7 weeks of treatment, high fat feeding had increased final body weight, glycemia, triacylglycerol, and total cholesterol levels in plasma and liver compared to the control diet. Collagen-induced platelet aggregation and basal platelet thromboxane B2 were also higher in the high-fat fed rats than in those in the control group. In the liver, oxidative stress was greater in the HF group than in the control group. O. aurita intake in HFOA-fed rats resulted in lower glycemia and lipid levels in the plasma and liver relative than in the HF group. Thus, in the HFOA group, n-3 polyunsaturated fatty acid levels in the tissues studied (plasma, liver, and platelets) were higher than in the HF group. Platelet hyper-aggregability tended to decrease in HFOA-fed rats as basal platelet thromboxane B2 production decreased. Finally, O. aurita reduced oxidative stress in the liver, with lower malondialdehyde levels and increased glutathione peroxidase activity.ConclusionsO. aurita is a marine diatom rich in EPA as well as in other bioactive molecules, such as pigments. The synergistic effect of these microalgal compounds, displayed a beneficial effect in reducing the risk factors for high-fat induced metabolic syndrome: hyperlipidemia, platelet aggregation, and oxidative stress.

Highlights

Dietary changes are a major factor in determining cardiovascular risk. n-3 polyunsaturated fatty acids modulate the risk factors for metabolic syndrome via multiple mechanisms, including the regulation of the lipid metabolism
When added to the diet, Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can alter the phospholipid membrane composition of the cells, and impact on the synthesis and action of eicosanoids, and regulate transcription factor activity and abundance. Another aspect of the action of n-3 fatty acids is to act as an important mediator of gene expression working via the peroxisome proliferator-activated receptors (PPARs) that control the expression of the genes involved in the lipid and glucose metabolism and adipogenesis [17]
Kajikawa et al [5] showed that oral administration of highly purified EPA ethyl ester (EPA-E) improved hepatic fat accumulation in high fat/high sucrose diet-fed mice by suppressing the triglyceride (TG) synthesis enzymes regulated by sterol regulatory element binding protein-1 (SREBP-1) and decreased the accumulation of hepatic monounsaturated fatty acids (MUFAs) produced by stearoyl-CoA desaturase 1 (SCD1)

Summary

Introduction

Dietary changes are a major factor in determining cardiovascular risk. n-3 polyunsaturated fatty acids modulate the risk factors for metabolic syndrome via multiple mechanisms, including the regulation of the lipid metabolism. While the prevalence of MS is increasing worldwide [10], studies have shown that recent dietary modifications such as low fat diets, high-fiber diets, Mediterranean diets and diets rich in flavonoids and phenolic acids can reduce MS risk factors [11,12]. Another way to reduce risk in patients with MS may be to increase the relative abundance of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) in the diet [13]. Adan et al [7] showed that EPA and DHA feeding reduces serum cholesterol and triacylcerol levels, and decreases platelet aggregation in hypercholesterolemic rats

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