A novel omega-3 free fatty acid formulation has dramatically improved bioavailability during a low-fat diet compared with omega-3-acid ethyl esters: the ECLIPSE (Epanova(®) compared to Lovaza(®) in a pharmacokinetic single-dose evaluation) study

Comparative Study of EPA-enriched Phosphatidylcholine and EPA-enriched Phosphatidylserine on Lipid Metabolism in Mice

Recent studies have shown that EPA enriched PLs have beneficial effects on lipid metabolism. Our previous study has demonstrated that the anti-obesity and hypolipidemic effects of EPA-PL were superior to DHA-PL. In the present study, we comparatively evaluated the effects of EPA-enriched phosphatidylcholine (EPA-PC) and EPA-enriched phosphatidylserine (EPA-PS) on lipid metabolism in mice. Both 2% dietary EPA-PC and EPA-PS significantly improved serum and hepatic lipid levels in mice. The HDL-c level in mice on EPA-PC diet was significantly higher than the other two groups. The level of DHA in hepatic TG and PL were significantly increased in both EPA-PC and EPA-PS fed groups (98.3 and 117.8%, respectively; p < 0.05). Notably, the proportion of DHA in EPA-PS group was significantly higher than the EPA-PC group. EPA-PC and EPA-PS suppressed hepatic SREBP-1c mediated lipogenesis and activated PPARα mediated fatty acid β-oxidation in the liver. These data are the first to indicate that EPA-PS has beneficial effects on lipid metabolism.

Nutraceuticals and Bioactive Components from Fish for Dyslipidemia and Cardiovascular Risk Reduction

Cardiovascular disease remains the most common health problem in developed countries, and residual risk after implementing all current therapies is still high. Permanent changes in lifestyle may be hard to achieve and people may not always be motivated enough to make the recommended modifications. Emerging research has explored the application of natural food-based strategies in disease management. In recent years, much focus has been placed on the beneficial effects of fish consumption. Many of the positive effects of fish consumption on dyslipidemia and heart diseases have been attributed to n-3 polyunsaturated fatty acids (n-3 PUFAs, i.e., EPA and DHA); however, fish is also an excellent source of protein and, recently, fish protein hydrolysates containing bioactive peptides have shown promising activities for the prevention/management of cardiovascular disease and associated health complications. The present review will focus on n-3 PUFAs and bioactive peptides effects on cardiovascular disease risk factors. Moreover, since considerable controversy exists regarding the association between n-3 PUFAs and major cardiovascular endpoints, we have also reviewed the main clinical trials supporting or not this association.

Omega-3 polyunsaturated fatty acid supplementation and white matter changes in major depression

White matter abnormalities are implicated in major depressive disorder (MDD). As omega-3 polyunsaturated fatty acids (PUFAs) are low in MDD and affect myelination, we hypothesized that PUFA supplementation may alleviate depression through improving white matter integrity. Acutely depressed MDD patients (n = 16) and healthy volunteers (HV, n = 12) had 25-direction diffusion tensor imaging before and after 6 weeks of fish oil supplementation. Plasma phospholipid omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and omega-6 PUFA arachidonic acid (AA) levels were determined before and after supplementation using high-throughput extraction and gas chromatography and expressed as a percentage of total phospholipids (PUFA%). Fractional anisotropy (FA) was computed using a least-squares-fit diffusion tensor with non-linear optimization. Regression analyses were performed with changes in PUFA levels or Hamilton Depression Rating Scale scores as predictors, voxel-wise difference maps of FA as outcome, covariates age and sex, with family-wise correction for multiple comparisons. Increases in plasma phospholipid DHA% (but not EPA% or AA%) after fish oil predicted increases in FA in MDD but not HV, in a cluster including genu and body of the corpus callosum, and anterior corona radiata and cingulum (cluster-level p < 0.001, peak t-score = 8.10, p = 0.002). There was a trend for greater change in FA in MDD responders over nonresponders (t = -1.874, df = 13.56, p = 0.08). Decreased depression severity predicted increased FA in left corticospinal tract and superior longitudinal fasciculus (cluster-level p < 0.001, peak t-score = 5.04, p = 0.0001). Increased FA correlated with increased DHA% and decreased depression severity after fish oil supplementation suggests therapeutic effects of omega-3 PUFAs may be related to improvements in white matter integrity.

Reduction in lipoprotein-associated apoC-III levels following volanesorsen therapy: phase 2 randomized trial results

Elevated apoC-III levels predict increased cardiovascular risk when present on LDL and HDL particles. We developed novel high-throughput chemiluminescent ELISAs that capture apoB, lipoprotein (a) [Lp(a)], and apoA-I in plasma and then detect apoC-III on these individual lipoproteins as apoCIII-apoB, apoCIII-Lp(a), and apoCIII-apoAI complexes, respectively. We assessed the effects on these complexes of placebo or 100-300 mg volanesorsen, a generation 2.0+ antisense drug that targets apoC3 mRNA in patients with hypertriglyceridemia, including familial chylomicronemia syndrome (n = 3), volanesorsen monotherapy (n = 51), and as add-on to fibrate (n = 26), treated for 85 days and followed for 176 days. Compared with placebo, volanesorsen was associated with an 82.3 ± 11.7%, 81.3 ± 15.7%, and 80.8 ± 13.6% reduction in apoCIII-apoB, apoCIII-Lp(a), and apoCIII-apoA-I, respectively (300 mg dose;P< 0.001 for all), at day 92. Strong correlations in all assay measures were noted with total plasma apoC-III, chylomicron-apoC-III, and VLDL-apoC-III. In conclusion, novel high-throughput ELISAs were developed to detect lipoprotein-associated apoC-III, including for the first time on Lp(a). Volanesorsen uniformly lowers apoC-III on apoB-100, Lp(a), and apoA-I lipoproteins, and may be a potent agent to reduce triglycerides and cardiovascular risk mediated by apoC-III.

Docosahexaenoic acid at the sn-2 position of structured triacylglycerols improved n-3 polyunsaturated fatty acid assimilation in tissues of hamsters

In this study, we hypothesized that the incorporation of docosahexaenoic acid (DHA) in tissues will be higher when it is ingested as triacylglycerols (TAG) structured at the sn-2 position, which enhances efficacy and health benefits of dietary DHA n-3 supplementation. Ten-week-old Golden Syrian male hamsters were randomly allocated into 4 dietary groups with 10 animals in each: linseed oil (LSO; control group), fish oil (FO), fish oil ethyl esters (FO-EE), and structured DHA at the sn-2 position of TAG (DHA-SL). After 12 weeks, there were no variations in the hamsters' body composition parameters across dietary groups. The DHA-SL diet had the lowest values of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total lipids, and aspartate aminotransferase activity, whereas the inverse was observed for the FO diet. Glucose was increased in the LSO diet without affecting insulin and insulin resistance markers. Whereas n-3 polyunsaturated fatty acid was increased in the brain of hamsters fed the DHA-SL diet, higher levels of n-6 polyunsaturated fatty acid were observed in the liver and erythrocytes of the LSO. The highest omega-3 index was obtained with the DHA-SL diet. The principal component analyses discriminated DHA from other metabolites and set apart 4 clusters matching the 4 diets. Similarly, liver, erythrocytes, and brain were separated from each other, pointing toward an individual signature on fatty acid deposition. The structured sn-2 position DHA-containing TAG ameliorated blood lipids and fatty acid incorporation, in particular eicosapentaenoic acid and DHA in liver, erythrocytes, and brain, relative to commercially FOs, thus improving the health benefits of DHA due to its higher bioavailability.

The Pharmacokinetic Profile of a New Gastroresistant Capsule Preparation of Eicosapentaenoic Acid as the Free Fatty Acid

Supplementation with n-3 polyunsaturated fatty acids (n-3 PUFAs) may be beneficial for patients with inflammatory bowel diseases (IBD). In this study we analyzed the pharmacokinetic profile of eicosapentaenoic acid (EPA), as the free fatty acid (FFA), in an enteric-coated preparation, in 10 ulcerative colitis (UC) and 10 Crohn's disease (CD) patients and 15 healthy volunteers (HV). Subjects received 2 g daily of EPA-FFA for 8 weeks. Plasma phospholipid and red blood cell (RBC) membrane fatty acid content were measured by gas chromatography-mass spectrometry. There was a rapid incorporation of EPA into plasma phospholipids by 2 weeks and a slower, but highly consistent, incorporation into RBC membranes (4% total fatty acid content; coefficient of variation 10–16%). There was a concomitant reduction in relative n-6 PUFA content. Elongation and desaturation of EPA into docosahexaenoic acid (DHA) via docosapentaenoic acid (DPA) were apparent and DHA content also increased in membranes. EPA-FFA is well tolerated and no difference in the pharmacokinetic profile of n-3 PUFA incorporation was detected between IBD patients and HV. Our data support the concept that EPA can be considered the “universal donor” with respect to key n-3 PUFAs and that this enteric-coated formulation allows long term treatment with a high level of compliance.

Omega-3 Polyunsaturated Fatty Acids: The Way Forward in Times of Mixed Evidence

Almost forty years ago, it was first hypothesized that an increased dietary intake of omega-3 polyunsaturated fatty acids (PUFA) from fish fat could exert protective effects against several pathologies. Decades of intense preclinical investigation have supported this hypothesis in a variety of model systems. Several clinical cardiovascular studies demonstrated the beneficial health effects of omega-3 PUFA, leading medical institutions worldwide to publish recommendations for their increased intake. However, particularly in recent years, contradictory results have been obtained in human studies focusing on cardiovascular disease and the clinical evidence in other diseases, particularly chronic inflammatory and neoplastic diseases, was never established to a degree that led to clear approval of treatment with omega-3 PUFA. Recent data not in line with the previous findings have sparked a debate on the health efficacy of omega-3 PUFA and the usefulness of increasing their intake for the prevention of a number of pathologies. In this review, we aim to examine the controversies on the possible use of these fatty acids as preventive/curative tools against the development of cardiovascular, metabolic, and inflammatory diseases, as well as several kinds of cancer.

Emerging nutrition science on fatty acids and cardiovascular disease: nutritionists' perspectives

Recent dietary guidance for heart health recommends a reduction (by ∼50%) in saturated fatty acid (SFA) intake to reduce LDL cholesterol and to decrease risk of cardiovascular disease (CVD). The 2010 Dietary Guidelines for Americans recommends substituting unsaturated fat [both polyunsaturated and monounsaturated fatty acids (PUFAs and MUFAs, respectively)] for SFAs. There are many dietary options that can be implemented to replace SFAs, given the different sources of unsaturated fats in the food supply. Compelling evidence exists for the cardioprotective benefits of n-3 (ω-3) PUFAs, both marine- and plant-derived. In addition, the evidence of cardioprotective benefits of n-6 (ω-6) PUFAs is strong, whereas that for MUFAs is mixed, although there is emerging evidence of benefits. Quantitatively, lowering SFAs by 50% will require, in part, substituting food sources of n-6 and n-3 PUFAs and MUFAs for food sources of SFAs. The use of n-3 PUFAs as a replacement for SFAs will result in a shortfall in reaching the SFA goal because of the relatively low amounts that can be incorporated in the diet, even with very high n-3 PUFA substitution. SFAs also can be replaced with dietary carbohydrate and/or protein. Replacing SFAs with carbohydrate, specifically refined sources, however, has little impact on reducing CVD risk. There is evidence about the health benefits of dietary protein on CVD risk, which merits study. Dietary guidelines have advanced considerably with the "replacement of SFA with unsaturated fat message" instead of recommending decreasing SFAs alone. A key question that remains is what is the optimal mix of macronutrients to maximally reduce CVD risk.

The free fractions of circulating docosahexaenoic acid and eicosapentenoic acid as optimal end-point of measure in bioavailability studies on n-3 fatty acids

The high complexity of n-3 fatty acids absorption process, along with the huge amount of endogenous fraction, makes bioavailability studies with these agents very challenging and deserving special consideration. In this paper we report the results of a bioequivalence study between a new formulation of EPA+DHA ethyl esters developed by IBSA Institut Biochimique and reference medicinal product present on the Italian market. Bioequivalence was demonstrated according to the criteria established by the EMA Guideline on the Investigation of Bioequivalence. We found that the free fractions represent a better and more sensitive end-point for bioequivalence investigations on n-3 fatty acids, since: (i) the overall and intra-subject variability of PK parameters was markedly lower compared to the same variability calculated on the total DHA and EPA fractions; (ii) the absorption process was completed within 4h, and the whole PK profile could be drawn within 12-15 h from drug administration.

Update on the management of severe hypertriglyceridemia--focus on free fatty acid forms of omega-3

High levels of plasma triglycerides (TG) are a risk factor for cardiovascular diseases, often associated with anomalies in other lipids or lipoproteins. Hypertriglyceridemia (HTG), particularly at very high levels, significantly increases also the risk of acute pancreatitis. Thus, interventions to lower TG levels are required to reduce the risk of pancreatitis and cardiovascular disease. Several strategies may be adopted for TG reduction, including lifestyle changes and pharmacological interventions. Among the available drugs, the most commonly used for HTG are fibrates, nicotinic acid, and omega-3 polyunsaturated fatty acids (usually a mixture of eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA). These last are available under different concentrated formulations containing high amounts of omega-3 fatty acids, including a mixture of EPA and DHA or pure EPA. The most recent formulation contains a free fatty acid (FFA) form of EPA and DHA, and exhibits a significantly higher bioavailability compared with the ethyl ester forms contained in the other formulations. This is due to the fact that the ethyl ester forms, to be absorbed, need to be hydrolyzed by the pancreatic enzymes that are secreted in response to fat intake, while the FFA do not. This higher bioavailability translates into a higher TG-lowering efficacy compared with the ethyl ester forms at equivalent doses. Omega-3 FFA are effective in reducing TG levels and other lipids in hypertriglyceridemic patients as well as in high cardiovascular risk patients treated with statins and residual HTG. Currently, omega-3 FFA formulation is under evaluation to establish whether, in high cardiovascular risk subjects, the addition of omega-3 to statin therapy may prevent or reduce major cardiovascular events.

Bioavailability of fatty acids from krill oil, krill meal and fish oil in healthy subjects--a randomized, single-dose, cross-over trial

Background

Krill contains two marine omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), mainly bound in phospholipids. Typical products from krill are krill oil and krill meal. Fish oils contain EPA and DHA predominantly bound in triglycerides. The difference in the chemical binding of EPA and DHA has been suggested to affect their bioavailability, but little is known on bioavailability of EPA and DHA in krill meal.

This study was undertaken to compare the acute bioavailability of two krill products, krill oil and krill meal, with fish oil in healthy subjects.

Methods

A randomized, single-dose, single-blind, cross-over, active-reference trial was conducted in 15 subjects, who ingested krill oil, krill meal and fish oil, each containing approx. 1 700 mg EPA and DHA. Fatty acid compositions of plasma triglycerides and phospholipids were measured repeatedly for 72 hours. The primary efficacy analysis was based on the 72 hour incremental area under the curve (iAUC) of EPA and DHA in plasma phospholipid fatty acids.

Results

A larger iAUC for EPA and DHA in plasma phospholipid fatty acids was detected after krill oil (mean 89.08 ± 33.36% × h) than after krill meal (mean 44.97 ± 18.07% x h, p < 0.001) or after fish oil (mean 59.15 ± 22.22% × h, p=0.003). Mean iAUC’s after krill meal and after fish oil were not different. A large inter-individual variability in response was observed.

Conclusion

EPA and DHA in krill oil had a higher 72-hour bioavailability than in krill meal or fish oil. Our finding that bioavailabilities of EPA and DHA in krill meal and fish oil were not different argues against the interpretation that phospholipids are better absorbed than triglycerides. Longer-term studies using a parameter reflecting tissue fatty acid composition, like erythrocyte EPA plus DHA are needed.

Trial registration

NCT02089165

Omega-3 fatty acids in cardiovascular disease--an uphill battle

In cardiology, results of recent large intervention trials with eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) supplements were neutral. In contrast, in epidemiologic studies, an inverse relation between clinical events and intake of EPA+DHA was found which was steeper for higher levels of EPA+DHA. A standardized way of determining levels is the Omega-3 Index, which is the percentage of EPA+DHA of a total of 26 fatty acids measured in erythrocytes. According to current criteria, a low Omega-3 Index is a cardiovascular risk factor. What can explain this contradiction? Trial participants were recruited irrespective of their baseline status in EPA+DHA - an important predictor of events. Levels of EPA+DHA have a statistically normal distribution; together with the large inter-individual variability of levels' responding to increased intake, this created a large overlap of EPA+DHA levels between intervention and control groups. Moreover, trial participants were advised to take EPA+DHA supplements with breakfast, frequently a low fat meal, resulting in poor bioavailability. As a result, there is an urgent need for new intervention trials in cardiology, for which participants with a low baseline omega-3 index are recruited, and then treated with individually tailored doses of EPA+DHA to a prespecified target range.

ω-3 carboxylic acids for hypertriglyceridemia

INTRODUCTION

ω-3 carboxylic acids (ω3 CA), also called ω3 free fatty acids (ω3 FFA), with the trade name Epanova™ is a new formulation of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) approved for the treatment of severe hypertriglyceridemia. The FFA form of EPA and DHA is associated with higher bioavailability than other forms of ω3 fatty acids, potentially resulting in efficacy at lower doses and less dependence on meal relationship.

AREAS COVERED

The efficacy and safety of ω3 CA from clinical trials as well as PK and PD data will be reviewed. The mechanism of action of ω3 fatty acids in the lowering of triglycerides (TG) will be discussed and comparison is made with ω3 ethyl ester compounds.

EXPERT OPINION

ω3 CA are a unique form of ω3 fatty acids that appear safe and effective in lowering serum TG and offer the possibility of better patient compliance due to lower-dose efficacy and the ability to take with or without food. ω3 CA lowered TG by 26 and 31% for the 2 and 4 g/day doses, respectively, and Apo CIII was also lowered 11 and 14%, respectively, as well.

Omega-3 carboxylic acids (Epanova): a review of its use in patients with severe hypertriglyceridemia

Omega-3 carboxylic acids (Epanova) [OM3-CA] is the first free fatty acid form of long-chain marine omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid being the most abundant) to be approved by the US FDA as an adjunct to diet to lower triglyceride levels in patients with severe hypertriglyceridemia (≥ 500 mg/dL). Oral OM3-CA has greater bioavailability than ethyl ester forms of omega-3 and, unlike omega-3 acid ethyl esters, does not require co-ingestion of a high-fat meal, as it does not need pancreatic enzyme activity for absorption. In the 12-week EpanoVa fOr Lowering Very high triglyceridEs (EVOLVE) trial, OM3-CA 2 or 4 g/day significantly reduced serum triglyceride levels relative to placebo. Other lipid parameters, including non-high-density lipoprotein cholesterol (non-HDL-C), total cholesterol, and very low-density lipoprotein cholesterol (VLDL-C) levels, were also reduced significantly with OM3-CA relative to placebo. Low-density lipoprotein cholesterol levels were increased significantly with OM3-CA relative to placebo; however, these increases were not accompanied by increases in the circulating concentrations of non-HDL-C, VLDL-C, or apolipoprotein B. OM3-CA was generally well tolerated in this study, with most adverse events being of mild or moderate severity. Although additional comparative data are needed to position OM3-CA with respect to other formulations of omega-3 fatty acids, current evidence suggests that OM3-CA is a useful addition to the treatment options available for patients with severe hypertriglyceridemia.

The fish oil ingredient, docosahexaenoic acid, activates cytosolic phospholipase A₂ via GPR120 receptor to produce prostaglandin E₂ and plays an anti-inflammatory role in macrophages

Docosahexaenoic acid (DHA) is one of the major ingredients of fish oil and has been reported to have anti-inflammatory properties mediated through the GPR120 receptor. Whether cytosolic phospholipase A2 (cPLA2 ) and lipid mediators produced from cPLA2 activation are involved in the anti-inflammatory role of DHA in macrophages has not been reported. We report here that DHA and the GPR120 agonist, GW9508, activate cPLA2 and cyclooxygenase 2 (COX-2), and cause prostaglandin E2 (PGE2) release in a murine macrophage cell line RAW264.7 and in human primary monocyte-derived macrophages. DHA and GW9508 activate cPLA2 via GPR120 receptor, G protein Gαq and scaffold protein β-arrestin 2. Extracellular signal-regulated kinase 1/2 activation is involved in DHA- and GW9508-induced cPLA2 activation, but not p38 mitogen-activated protein kinase. The anti-inflammatory role of DHA and GW9508 is in part via activation of cPLA2 , COX-2 and production of PGE2 as a cPLA2 inhibitor or a COX-2 inhibitor partially reverses the DHA- and GW9508-induced inhibition of lipopolysaccharide-induced interleukin-6 secretion. The cPLA2 product arachidonic acid and PGE2 also play an anti-inflammatory role. This effect of PGE2 is partially through inhibition of the nuclear factor-κB signalling pathway and through the EP4 receptor of PGE2 because an EP4 inhibitor or knock-down of EP4 partially reverses DHA inhibition of lipopolysaccharide-induced interleukin-6 secretion. Hence, DHA has an anti-inflammatory effect partially through induction of PGE2.

Recent advances in pharmacotherapy for hypertriglyceridemia

Elevated plasma triglyceride (TG) concentrations are associated with an increased risk of atherosclerotic cardiovascular disease (CVD), hepatic steatosis and pancreatitis. Existing pharmacotherapies, such as fibrates, n-3 polyunsaturated fatty acids (PUFAs) and niacin, are partially efficacious in correcting elevated plasma TG. However, several new TG-lowering agents are in development that can regulate the transport of triglyceride-rich lipoproteins (TRLs) by modulating key enzymes, receptors or ligands involved in their metabolism. Balanced dual peroxisome proliferator-activated receptor (PPAR) α/γ agonists, inhibitors of microsomal triglyceride transfer protein (MTTP) and acyl-CoA:diacylglycerol acyltransferase-1 (DGAT-1), incretin mimetics, and apolipoprotein (apo) B-targeted antisense oligonucleotides (ASOs) can all decrease the production and secretion of TRLs; inhibitors of cholesteryl ester transfer protein (CETP) and angiopoietin-like proteins (ANGPTLs) 3 and 4, monoclonal antibodies (Mabs) against proprotein convertase subtilisin/kexin type 9 (PCSK9), apoC-III-targeted ASOs, selective peroxisome proliferator-activated receptor modulators (SPPARMs), and lipoprotein lipase (LPL) gene replacement therapy (alipogene tiparvovec) enhance the catabolism and clearance of TRLs; dual PPAR-α/δ agonists and n-3 polyunsaturated fatty acids can lower plasma TG by regulating both TRL secretion and catabolism. Varying degrees of TG reduction have been reported with the use of these therapies, and for some agents such as CETP inhibitors and PCSK9 Mabs findings have not been consistent. Whether they reduce CVD events has not been established. Trials investigating the effect of CETP inhibitors (anacetrapib and evacetrapib) and PCSK9 Mabs (AMG-145 and REGN727/SAR236553) on CVD outcomes are currently in progress, although these agents also regulate LDL metabolism and, in the case of CETP inhibitors, HDL metabolism. Further to CVD risk reduction, these new treatments might also have a potential role in the management of diabetes and non-alcoholic fatty liver disease owing to their insulin-sensitizing action (PPAR-α/γ agonists) and potential capacity to decrease hepatic TG accumulation (PPAR-α/δ agonists and DGAT-1 inhibitors), but this needs to be tested in future trials. We summarize the clinical trial findings regarding the efficacy and safety of these novel therapies for hypertriglyceridemia.

A randomized clinical trial to determine the efficacy of manufacturers' recommended doses of omega-3 fatty acids from different sources in facilitating cardiovascular disease risk reduction

BACKGROUND

Omega-3 fatty acids confer beneficial health effects, but North Americans are lacking in their dietary omega-3-rich intake. Supplementation is an alternative to consumption of fish; however, not all omega-3 products are created equal. The trial objective was to compare the increases in blood levels of omega-3 fatty acids after consumption of four different omega-3 supplements, and to assess potential changes in cardiovascular disease risk following supplementation.

METHODS

This was an open-label, randomized, cross-over study involving thirty-five healthy subjects. Supplements and daily doses (as recommended on product labels) were:Concentrated Triglyceride (rTG) fish oil: EPA of 650 mg, DHA of 450 mgEthyl Ester (EE) fish oil: EPA of 756 mg, DHA of 228 mgPhospholipid (PL) krill oil: EPA of 150 mg, DHA of 90 mgTriglyceride (TG) salmon oil: EPA of 180 mg, DHA of 220 mg.Subjects were randomly assigned to consume one of four products, in random order, for a 28-day period, followed by a 4-week washout period. Subsequent testing of the remaining three products, followed by 4-week washout periods, continued until each subject had consumed each of the products. Blood samples before and after supplementation were quantified for fatty acid analysis using gas chromatography, and statistically analysed using ANOVA for repeated measures.

RESULTS

At the prescribed dosage, the statistical ranking of the four products in terms of increase in whole blood omega-3 fatty acid levels was concentrated rTG fish oil > EE fish oil > triglyceride TG salmon oil > PL krill oil. Whole blood EPA percentage increase in subjects consuming concentrated rTG fish oil was more than four times that of krill and salmon oil. Risk reduction in several elements of cardiovascular disease was achieved to a greater extent by the concentrated rTG fish oil than by any other supplement. Krill oil and (unconcentrated) triglyceride oil were relatively unsuccessful in this aspect of the study.

CONCLUSION

For the general population, the form and dose of omega-3 supplements may be immaterial. However, given these results, the form and dose may be important for those interested in reducing their risk of cardiovascular disease.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01960660.

Phospholipids from herring roe improve plasma lipids and glucose tolerance in healthy, young adults

BACKGROUND

Herring roe is an underutilized source of n-3 polyunsaturated fatty acids (PUFAs) for human consumption with high phospholipid (PL) content. Studies have shown that PL may improve bioavailability of n-3 PUFAs. Arctic Nutrition's herring roe product MOPL™30 is a PL: docosahexaenoic acid (DHA)-rich fish oil mixture, with a DHA:eicosapentaenoic acid (EPA) ratio of about 3:1, which is also rich in choline. In this pilot study, we determined if MOPL30 could favorably affect plasma lipid parameters and glucose tolerance in healthy young adults.

METHODS

Twenty female and one male adults, between 22 and 26 years of age, participated in the study. Participants took encapsulated MOPL30, 2.4 g/d EPA + DHA, for 14 days, and completed a three-day weighed food record before and during the capsule intake. Plasma lipids and their fatty acid (FA) composition, plasma and red blood cell (RBC) phosphatidylcholine (PC) FA composition, acylcarnitines, choline, betaine and insulin were measured before and after supplementation (n = 21), and one and four weeks after discontinuation of supplementation (n = 14). An oral glucose tolerance test was performed before and after supplementation.

RESULTS

Fasting plasma triacylglycerol and non-esterified fatty acids decreased and HDL-cholesterol increased after 14 days of MOPL30 intake (p < 0.05). The dietary records showed that PUFA intake prior to and during capsule intake was not different. Fasting plasma glucose was unchanged from before to after supplementation. However, during oral glucose tolerance testing, blood glucose at both 10 and 120 min was significantly lower after supplementation with MOPL30 compared to baseline measurements. Plasma free choline and betaine were increased, and the n-6/n-3 polyunsaturated (PUFA) ratio in plasma and RBC PC were decreased post-supplementation. Four weeks after discontinuation of MOPL30, most parameters had returned to baseline, but a delayed effect was observed on n-6 PUFAs.

CONCLUSIONS

Herring roe rich in PL improved the plasma lipid profile and glycemic control in young adults with an overall healthy lifestyle.

Omega-3 polyunsaturated fatty acids in the treatment of atherogenic dyslipidemia

Epidemiological studies have established an association between high triglycerides (TG) plasma levels and increased cardiovascular risk. Increased TG levels, commonly coupled with low HDL-C levels, are common in high cardiovascular risk subjects including those with dyslipidemia, metabolic syndrome and type 2 diabetes. Management of hypertriglyceridemia (HTG) includes lifestyle modification for mild-to-moderate HTG and pharmacological therapies for the treatment of high and very high TG levels. Among drugs, fibrates, nicotinic acid and omega-3 polyunsaturated fatty acids may be considered. Omega-3 fatty acids reduce plasma TG levels by several mechanisms; beside the effects on TG, omega-3 can also influence the levels of other lipids and lipoproteins including HDL-C and LDL-C. Clinical trials have also shown that omega-3 fatty acid supplementation is effective also when added in combination with other lipid-lowering drugs. These findings suggest that omega-3 fatty acids may be usefully considered for the management of high TG levels.

Omega-3 index and cardiovascular health

Recent large trials with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the cardiovascular field did not demonstrate a beneficial effect in terms of reductions of clinical endpoints like total mortality, sudden cardiac arrest or other major adverse cardiac events. Pertinent guidelines do not uniformly recommend EPA + DHA for cardiac patients. In contrast, in epidemiologic findings, higher blood levels of EPA + DHA were consistently associated with a lower risk for the endpoints mentioned. Because of low biological and analytical variability, a standardized analytical procedure, a large database and for other reasons, blood levels of EPA + DHA are frequently assessed in erythrocytes, using the HS-Omega-3 Index® methodology. A low Omega-3 Index fulfills the current criteria for a novel cardiovascular risk factor. Neutral results of intervention trials can be explained by issues of bioavailability and trial design that surfaced after the trials were initiated. In the future, incorporating the Omega-3 Index into trial designs by recruiting participants with a low Omega-3 Index and treating them within a pre-specified target range (e.g., 8%-11%), will make more efficient trials possible and provide clearer answers to the questions asked than previously possible.

Effects of Krill-derived phospholipid-enriched n-3 fatty acids on Ca(2+) regulation system in cerebral arteries from ovariectomized rats

AIMS

To investigate the effects of n-3 polyunsaturated fatty acids on cerebral circulation, ovariectomized (OVX) rats were administered with phospholipids in krill oil (KPL) or triglycerides in fish oil (FTG); effects on the Ca(2+) regulating system in their basilar artery (BA) were then analyzed.

MAIN METHODS

The rats were divided into 4 groups: control, OVX, OVX given KPL (OVXP), and OVX given FTG (OVXT) orally, daily for 2weeks. Time dependent relaxation (TDR) of contractile response to 5HT in BA was determined myographically, Na(+)/Ca(2+) exchanger (NCX) 1 mRNA expression was determined by real time PCR, and nucleotides were analyzed by HPLC.

KEY FINDINGS

The level of TDR in OVX that was significantly lower in the control was inhibited by l-NAME and indomethacin; TEA inhibited TDR totally in the control but only partly in OVXP and OVXT. Relaxation induced by the addition of 5mM KCl to the BA pre-contracted with 5-HT was inhibited by TEA in the controls, OVXP and OVXT, but not in OVX. Overexpression of NCX1 mRNA in the BA from OVX was significantly inhibited by FTG. The ratio of ADP/ATP in cerebral arteries from OVX was significantly inhibited by KPL and FTG. Levels of triglyceride and arachidonic acid in the plasma of OVX increased, but were significantly inhibited by KPL and FTG.

SIGNIFICANCE

Ovarian dysfunction affects Ca(2+) activated-, ATP-sensitive-K(+) channels and NCX1, which play crucial roles in the autoregulation of cerebral blood flow. Also, KPL may become as good a supplement as FTG for postmenopausal women.

Comparison of the bioavailability of docosapentaenoic acid (DPA, 22:5n-3) and eicosapentaenoic acid (EPA, 20:5n-3) in the rat

Based on the results from a human study which showed significantly reduced incorporation of DPA compared with EPA into chylomicrons, this study was designed to test if dietary DPA was significantly less absorbed than EPA. Male Sprague Dawley rats were randomly assigned to three groups of six, and were fed a semi-synthetic high fat diet (23.5% fat) for 9 days. The test omega 3 fatty acids (EPA and DPA, 250mg/animal/day, free fatty acid form) or olive oil (250mg/animal/day) were added to the high fat diet on days 5, 6 and 7. Dietary EPA and DPA appeared in the faeces on days 6, 7 and 8, with the total amount of DPA excreted being 4.6-fold greater than that of EPA. The total amount of faecal fat did not differ significantly between the groups. At the conclusion of the study (day 9), it was found that liver DPA, EPA and total n-3 LC-PUFA levels were significantly increased by both DPA and EPA feeding compared with the olive oil fed control group. In the heart, DPA feeding increased the DPA content and both DPA and EPA feeding increased the total n-3 LC-PUFA levels. This study showed that DPA and EPA, both provided in free form, are metabolised differently, despite being chemically similar.

Omega-3 fatty acids: new insights into the pharmacology and biology of docosahexaenoic acid, docosapentaenoic acid, and eicosapentaenoic acid

PURPOSE OF REVIEW

Fish oil contains a complex mixture of omega-3 fatty acids, which are predominantly eicosapentaenoic acid (EPA), docosapentaenoic acid, and docosahexaenoic acid (DHA). Each of these omega-3 fatty acids has distinct biological effects that may have variable clinical effects. In addition, plasma levels of omega-3 fatty acids are affected not only by dietary intake, but also by the polymorphisms of coding genes fatty acid desaturase 1-3 for the desaturase enzymes that convert short-chain polyunsaturated fatty acids to long-chain polyunsaturated fatty acids. The clinical significance of this new understanding regarding the complexity of omega-3 fatty acid biology is the purpose of this review.

RECENT FINDINGS

FADS polymorphisms that result in either lower levels of long-chain omega-3 fatty acids or higher levels of long-chain omega-6 polyunsaturated fatty acids, such as arachidonic acid, are associated with dyslipidemia and other cardiovascular risk factors. EPA and DHA have differences in their effects on lipoprotein metabolism, in which EPA, with a more potent peroxisome proliferator-activated receptor-alpha effect, decreases hepatic lipogenesis, whereas DHA not only enhances VLDL lipolysis, resulting in greater conversion to LDL, but also increases HDL cholesterol and larger, more buoyant LDL particles.

SUMMARY

Overall, these results emphasize that blood concentrations of individual long-chain polyunsaturated fatty acids, which reflect both dietary intake and metabolic influences, may have independent, but also complementary- biological effects and reinforce the need to potentially provide a complex mixture of omega-3 fatty acids to maximize cardiovascular risk reduction.

Pharmacokinetics of Eicosapentaenoic Acid in Plasma and Red Blood Cells After Multiple Oral Dosing With Icosapent Ethyl in Healthy Subjects

Objective

Icosapent ethyl (IPE) is a prescription form of eicosapentaenoic acid (EPA) ethyl ester. This randomized, open-label study characterized EPA pharmacokinetics.

Methods

Four healthy subject groups received IPE for 28 days: three received 2 g/day (1 × 1,000 mg BID, 2 × 1,000 mg QD, or 2 × 500 mg BID); one received 4 g/day (2 × 1,000 mg BID) administered with meals. Blood sampling was before the morning dose on days 1, 14, 26, 28, and at specified intervals during an 18-day pharmacokinetic period. EPA was measured in plasma (total and unesterified) and red blood cells (RBCs) by liquid chromatography/tandem mass spectrometry.

Results

Mean plasma total EPA increased from 19 µg/mL to a peak (C_max) of 366 µg/mL at 5 hours postdosing 4 g/day IPE on Day 28. Mean RBC EPA C_max after 4 g/day was 89 µg/mL (baseline, 12 µg/mL). Mean steady state (SD) for half-life, clearance, and volume of distribution of total EPA were 79 (47) hours, 757 (283) mL/h, and 82 (56) L, respectively. Steady state for total and unesterified plasma EPA was reached by Day 28, whereas RBC levels were still increasing.

Conclusions

EPA pharmacokinetic profile demonstrated a slowly cleared, extensively distributed molecule with dose linearity and comparable exposures with BID and QD regimens.

Steady-state bioavailability of prescription omega-3 on a low-fat diet is significantly improved with a free fatty acid formulation compared with an ethyl ester formulation: the ECLIPSE II study

The systemic bioavailability of free fatty acid (FFA) forms of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) compared with ethyl ester (EE) forms is dependent on the presence of intestinal lipases and is highest during consumption of high-fat meals. Given that patients with cardiovascular disease are advised to reduce dietary fat intake, potentially lowering the bioavailability and therapeutic benefit, the hypothesis that FFA forms provide for higher bioavailability compared with EE forms under low-fat diet conditions was tested where the pharmacokinetics of the FFA form (Epanova™) were compared with those of an ethyl ester form (Lovaza®) following repeat dosing. Fifty-two healthy male and female subjects were equally allocated to one of two open-label, parallel-group cohorts. Following a Therapeutic Lifestyle Changes diet for a minimum of 7 days, blood samples were drawn for endogenous values for EPA and DHA over a 24-hour period. Subjects were then administered 4 × 1 g capsules of either Epanova (OM3 FFA) or Lovaza (OM3 EE) once daily for 14 days, following which serial blood samples were drawn over a 24-hour period to characterize the bioavailability of EPA and DHA from the respective formulations. In addition, changes from baseline in lipid profile were explored. Systemic bioavailability, as measured by area under the curve from time zero to 24 hours (AUC_0-τ) and the maximum measured plasma concentrations during the 0–24 hour dosing interval (C_max,ss) of unadjusted total plasma EPA + DHA were approximately 3-fold and 3.9-fold higher, respectively, for Epanova relative to Lovaza. Following baseline adjustment, the magnitude of difference in bioavailability was approximately 5.8-fold and 6.5-fold higher in AUC_0-τ and C_max, respectively, for Epanova relative to Lovaza. Serum triglycerides were reduced by a significantly greater extent (P = 0.013) for Epanova relative to Lovaza (21% versus 8%). The bioavailability of the FFA forms of EPA and DHA in Epanova are significantly greater than the bioavailability from the EE forms present in Lovaza under low-fat dietary conditions normally recommended for patients with cardiovascular disease. This increased bioavailability may lead to improved triglyceride-lowering in patients with hypertriglyceridemia.

Bioavailability of long-chain omega-3 fatty acids

Supplements have reached a prominent role in improving the supply of long-chain omega-3 fatty acids, such as Eicosapentaenoic acid (EPA 20:5n-3) and Docosahexaenoic acid (DHA 22:6n-3). Similar to other nutrients, the availability of omega-3 fatty acids is highly variable and determined by numerous factors. However, the question of omega-3 fatty acids bioavailability has long been disregarded, which may have contributed to the neutral or negative results concerning their effects in several studies. This review provides an overview of the influence of chemical binding form (free fatty acids bound in ethylesters, triacylglycerides or phospholipids), matrix effects (capsule ingestion with concomitant intake of food, fat content in food) or galenic form (i.e. microencapsulation, emulsification) on the bioavailability of omega-3 fatty acids. There is a need to systematically investigate the bioavailability of omega-3 fatty acids formulations, which might be a key to designing more effective studies in the future.

Epanova® and hypertriglyceridemia: pharmacological mechanisms and clinical efficacy

While LDL-cholesterol lowering has become the cornerstone of cardiovascular risk reduction strategies, considerable interest in additional targeting of hypertriglyceridemia continues. While ω-3 fatty acids are commonly used in clinical practice for triglyceride lowering, no large-scale clinical trial evaluating their impact on clinical events has been performed. As a result, there remains a lack of consensus with regards to their optimal clinical use. Epanova® (Omthera Pharmaceuticals Inc., NJ, USA) is a novel ω-3 free fatty acid formulation, developed to maximize eicosapentenoic acid and docosahexenoic acid bioavailability with low-fat diets, suggesting a potential therapeutic advantage compared with ω-3-acid ethyl esters in the treatment of patients with hypertriglyceridemia. Additional human studies are needed to define more clearly the cellular and molecular basis for the triglyceride-lowering effects of Epanova and this drug’s favorable cardiovascular effects, particularly in patients with hypertriglyceridemia.