EPA Incorporation Research Articles

Dynamics of DHA and EPA supplementation: incorporation into equine plasma, synovial fluid, and surfactant glycerophosphocholines.

Horses with asthma or osteoarthritis frequently receive ω-3 fatty acid supplements. Docosahexaenoic (DHA; 22:6) and eicosapentaenoic (EPA; 20:5) acids are essential ω-3 fatty acid precursors of anti-inflammatory mediators and components of structural glycerophospholipids (GPL) that act as reservoirs of these fatty acids. Analysis of the incorporation of dietary DHA + EPA into GPL pools in different body compartments has not been undertaken in horses. We undertook a detailed study of dietary supplementation with DHA + EPA in horses and monitored incorporation into DHA- and EPA-containing glycerophosphocholines (GPC) 38:5, 38:6, 40:5, and 40:6 in plasma, synovial fluid (SF), and surfactant. Horses (n = 20) were randomly assigned to the supplement or control group and evaluated on days 0, 30, 60, and 90. GPC in plasma, SF, and surfactant were measured by high-resolution mass spectrometry with less than 3ppm mass error. Validation of DHA and EPA incorporation into these GPC was conducted utilizing MS2 of the [M + Cl]- adducts of GPC. Dietary supplementation resulted in augmented levels of GPC 38:5, 38:6, 40:5, and 40:6 in all compartments. Maximum incorporation into GPCs was delayed until 60days. Significant increases in the levels of GPC 38:5, 40:5, and 40:6, containing docosapentaenoic acid (DPA; 22:5), also was noted. DHA and EPA supplementation results in augmented storage pools of ω-3 essential fatty acids in SF and surfactant GPC. This has the potential to improve the ability of anti-inflammatory mechanisms to resolve inflammatory pathways in these critical compartments involved in arthritis and asthma.

Postprandial incorporation of EPA and DHA from transgenic Camelina sativa oil into blood lipids is equivalent to that from fish oil in healthy humans.

EPA and DHA are important components of cell membranes. Since humans have limited ability for EPA and DHA synthesis, these must be obtained from the diet, primarily from oily fish. Dietary EPA and DHA intakes are constrained by the size of fish stocks and by food choice. Seed oil from transgenic plants that synthesise EPA and DHA represents a potential alternative source of these fatty acids, but this has not been tested in humans. We hypothesised that incorporation of EPA and DHA into blood lipids from transgenic Camelina sativa seed oil (CSO) is equivalent to that from fish oil. Healthy men and women (18-30 years or 50-65 years) consumed 450 mg EPA + DHA from either CSO or commercial blended fish oil (BFO) in test meals in a double-blind, postprandial cross-over trial. There were no significant differences between test oils or sexes in EPA and DHA incorporation into plasma TAG, phosphatidylcholine or NEFA over 8 h. There were no significant differences between test oils, age groups or sexes in postprandial VLDL, LDL or HDL sizes or concentrations. There were no significant differences between test oils in postprandial plasma TNFα, IL 6 or 10, or soluble intercellular cell adhesion molecule-1 concentrations in younger participants. These findings show that incorporation into blood lipids of EPA and DHA consumed as CSO was equivalent to BFO and that such transgenic plant oils are a suitable dietary source of EPA and DHA in humans.

Lipid structure does not modify incorporation of EPA and DHA into blood lipids in healthy adults: a randomised-controlled trial.

Dietary supplementation is an effective means to improve EPA and DHA status. However, it is unclear whether lipid structure affects EPA+DHA bioavailability. We determined the effect of consuming different EPA and DHA lipid structures on their concentrations in blood during the postprandial period and during dietary supplementation compared with unmodified fish oil TAG (uTAG). In a postprandial cross-over study, healthy men (n 9) consumed in random order test meals containing 1·1 g EPA+0·37 g DHA as either uTAG, re-esterified TAG, free fatty acids (FFA) or ethyl esters (EE). In a parallel design supplementation study, healthy men and women (n 10/sex per supplement) consumed one supplement type for 12 weeks. Fatty acid composition was determined by GC. EPA incorporation over 6 h into TAG or phosphatidylcholine (PC) did not differ between lipid structures. EPA enrichment in NEFA was lower from EE than from uTAG (P=0·01). Plasma TAG, PC or NEFA DHA incorporation did not differ between lipid structures. Lipid structure did not affect TAG or NEFA EPA incorporation and PC or NEFA DHA incorporation following dietary supplementation. Plasma TAG peak DHA incorporation was greater (P=0·02) and time to peak shorter (P=0·02) from FFA than from uTAG in men. In both studies, the order of EPA and DHA incorporation was PC>TAG>NEFA. In conclusion, EPA and DHA lipid structure may not be an important consideration in dietary interventions.

Kinetics of eicosapentaenoic acid in brain, heart and liver of conscious rats fed a high n-3 PUFA containing diet

Eicosapentaenoic acid (EPA, 20:5n-3), a precursor of docosahexaenoic acid (DHA), may benefit cardiovascular and brain health. Quantifying EPA's in vivo kinetics might elucidate these effects. [1-14C]EPA was infused i.v. for 5min in unanesthetized male rats fed a standard EPA–DHA diet. Plasma and microwaved tissue were analyzed. Kinetic parameters were calculated using our compartmental model. At 5min, 31–48% of labeled EPA in brain and heart was oxidized, 7% in liver. EPA incorporation rates from brain and liver precursor EPA–CoA pools into lipids, mainly phospholipids, were 36 and 2529nmol/s/g×10−4, insignificant for heart. Deacylation–reacylation half-lives were 22h and 38–128min. Conversion rates to DHA equaled 0.65 and 25.1nmol/s/g×10−4, respectively. The low brain concentration and incorporation rate and high oxidation of EPA suggest that, if EPA has a beneficial effect in brain, it might result from its suppression of peripheral inflammation and hepatic conversion to bioactive DHA.

Rapid EPA and DHA incorporation and reduced PGE2 levels after one week intervention with a medical food in cancer patients receiving radiotherapy, a randomized trial

In cancer patients, metabolic alterations, reduced immune competence and anti-cancer treatment can increase the risk of infections. A rapid-acting nutritional intervention might reduce this risk and support overall treatment. The present study investigated whether one week of intervention with a specific medical food led to fatty acid incorporation and functional immunological changes. In a randomized, double-blind study, 38 cancer patients receiving radiotherapy consumed daily for one week 400 ml of specific medical food, which is high in protein and leucine, and enriched with fish oil and specific oligosaccharides (Active group), or iso-caloric/iso-nitrogenous product (Control group). Blood samples were taken at day 0 (baseline) and day 7. After one week of intervention, the incorporation of EPA and DHA in white blood cells was significantly higher in the Active group (2.6% and 2.6% of total fatty acids) compared to the Control group (1.0% and 2.2% of total fatty acids) (p < 0.001 and p < 0.05). Serum PGE2 levels decreased in the Active group and increased in the Control group (p < 0.01). No differences were observed on cytokine production in LPS-stimulated whole blood cultures. In cancer patients receiving radiotherapy, nutritional intervention with a specific medical food rapidly increased the percentage EPA and DHA in white blood cell phospholipids and reduced serum levels of the inflammatory mediator PGE2 within one week. CLINICAL REGISTRATION NUMBER: NTR2121.

Relative Bioavailability of an Emulsion Formulation for Omega-3-Acid Ethyl Esters Compared to the Commercially Available Formulation: A Randomized, Parallel-Group, Single-Dose Study Followed by Repeat Dosing in Healthy Volunteers.

LOVAZA (omega-3-acid ethyl esters; eicosapentaenoic acid [EPA]/docosahexaenoic acid [DHA]), with diet, lowers very high triglycerides (≥500 mg/dL) in adults. This study evaluated whether an emulsion formulation (LEM) increases the bioavailability of EPA/DHA compared to the reference formulation (RF) in healthy volunteers. Following relative bioavailability assessment, LEM, RF, and placebo were dosed for 2 weeks. Exposure measurements included plasma-free and total fatty acid (EPA/DHA) concentrations and phospholipid and red blood cell (RBC) incorporation. Following single doses, the dose-normalized EPA plasma-corrected AUCs were 14-fold (total) and 12-fold (free) higher and DHA plasma-corrected AUCs were 10-fold (total) and 13-fold (free) higher for LEM compared to RF. EPA and DHA incorporation into phospholipids increased for all active treatments; the increase was dose dependent for EPA. An 8-fold increase over baseline was observed in EPA incorporation for LEM (4-capsule dose) compared to a 4-fold increase for RF 4 g. DHA incorporation increased to a lesser degree, and RBC incorporation also increased. Pharmacodynamic evaluations revealed slight decreases (-8% to -25%) in the mean fasting triglyceride concentrations in all groups, including placebo, compared to baseline. Following a high-fat meal, no consistent treatment-related effect on the triglyceride profiles was observed. Study treatments were safe and tolerated. In conclusion, LEM improves the oral bioavailability of EPA and DHA.

Blunting the response to endotoxin in healthy subjects: effects of various doses of intravenous fish oil

To test the dose response effect of infused fish oil (FO) rich in n-3 PUFAs on the inflammatory response to endotoxin (LPS) and on membrane incorporation of fatty acids in healthy subjects. Prospective, sequential investigation comparing three different FO doses. Three groups of male subjects aged 26.8 +/- 3.2 years (BMI 22.5 +/- 2.1). One of three FO doses (Omegaven10%) as a slow infusion before LPS: 0.5 g/kg 1 day before LPS, 0.2 g/kg 1 day before, or 0.2 g/kg 2 h before. Temperature, hemodynamic variables, indirect calorimetry and blood samples (TNF-alpha, stress hormones) were collected. After LPS temperature, ACTH and TNF-alpha concentrations increased in the three groups: the responses were significantly blunted (p < 0.0001) compared with the control group of the Pluess et al. trial. Cortisol was unchanged. Lowest plasma ACTH, TNF-alpha and temperature AUC values were observed after a single 0.2 g/kg dose of FO. EPA incorporation into platelet membranes was dose-dependent. Having previously shown that the response to LPS was reproducible, this study shows that three FO doses blunted it to various degrees. The 0.2 g/kg perfusion immediately before LPS was the most efficient in blunting the responses, suggesting LPS capture in addition to the systemic and membrane effects.

Plasman-3 fatty acid response to ann-3 fatty acid supplement is modulated by apoE ɛ4 but not by the common PPAR-α L162V polymorphism in men

The risk of Alzheimer's disease is increased for carriers of apoE4 (E4) or the PPAR-alpha L162V polymorphism (L162V), but it is decreased in fish and seafood consumers. The link between high fish intake and reduced risk of cognitive decline in the elderly appears not to hold in carriers of E4, possibly because better cognition is linked to EPA+DHA in the blood, but only in non-carriers of E4. As yet, no such studies exist in carriers of L162V. Our objective was to determine whether the plasma fatty acid response to a dietary supplement of EPA+DHA was altered in carriers of L162V and/or E4. This was an add-on project; in the original study, men were selected based on whether or not they were carriers of L162V (n 14 per group). E4 status was determined afterwards. All subjects received an EPA+DHA supplement for 6 weeks. L162V polymorphism did not interact with the supplement in a way to alter EPA and DHA incorporation into plasma lipids. However, when the groups were separated based on the presence of E4, baseline EPA and DHA in plasma TAG were 67 and 60 % higher, respectively, in E4 carriers. After the supplementation, there were significant gene x diet interactions in which only non-carriers had increased EPA and DHA in plasma NEFA and TAG, respectively.

The effect of maternal T1DM on the fatty acid composition of erythrocyte phosphatidylcholine and phosphatidyethanolamine in infants during early life

The risk for type 1 diabetes (T1DM) in children of mothers with T1DM is different to that in children of fathers with T1DM. Fatty acid (FA) intake, in particular EPA and DHA, has been associated with T1DM risk and has been suggested to be inadequate in infants of diabetic mothers. We asked, therefore, whether EPA and DHA FA nutritional status in offspring of mothers with T1DM could contribute to their reduced T1DM risk. BABYDIET follows children with increased genetic and familial risk for T1DM from birth to age 3 years. FA nutritional state was assessed by determining the erythrocyte membrane phosphatidylethanolamine (PE) and phosphatidylcholine (PC) composition in children of T1DM mothers and children of T1DM fathers or with T1DM siblings participating in the BABYDIET study. Samples for determination of erythrocyte membrane FA composition were collected at ages 3 and 12 months in 48 and 49 infants, respectively. FA measurements were adjusted for breastfeeding duration, FA supplementation, and gluten exposure. 3-months-old children of T1DM mothers and T1DM fathers/sibs had similar levels of PC DHA and EPA (DHA 1.53+/-0.23 vs. 1.65+/-0.11 wt.%; EPA 0.15+/-0.02 vs. 0.21+/-0.03 wt.%) and PE DHA and EPA (DHA 7.54+/-0.37 vs. 7.92+/-0.38 wt.%; EPA 0.53+/-0.06 vs. 0.61+/-0.04 wt.%). No differences were also observed after stratification for breastfeeding. At age 12 months, a minor reduction of PE DHA was observed in children of T1DM mothers. Expected higher levels for DHA and EPA in fully breastfed children and in children of mothers taking fish oil supplementation were observed at 3 months in all children. Other differences included increased levels of the major saturated FA 16:0 in 3-months-old infants from T1DM mothers (PC 35.45+/-0.35 vs. 33.89+/-0.26 wt.%, mean +/- SEM, P(corr)=0.005; PE 16.13+/-0.39 vs. 14.93+/-0.24 wt.%, P(corr)=0.05). Although FA status was not identical in children from T1DM mothers and from T1DM fathers, maternal T1DM was not associated with changes in offspring's EPA and DHA incorporation into erythrocyte membrane.

Fatty acid profile and oxidative stability of pork as influenced by duration and time of dietary linseed or fish oil supplementation1

In this experiment, the effect of duration and time of feeding n-3 PUFA sources on the fatty acid composition and oxidative stability of the longissimus thoracis (LT) muscle was investigated. Linseed (L) and fish oil (F), rich in alpha-linolenic acid and eicosapentaenoic and docosahexaenoic acid (EPA and DHA), respectively, were supplied equivalent to a level of 1.2% oil (as fed), either during the whole fattening period or only during the first (P1; 8 wk) or second (P2; 6 to 9 wk until slaughter) fattening phase. All diets were based on barley, wheat, and soybean meal and were fed ad libitum. Crossbred pigs (n = 154; Topigs 40 x Piétrain) were randomly allotted to the 7 feeding groups. In the basal diet (B), only animal fat was used as the supplementary fat source. Three dietary groups were supplied the same fatty acid source during both fattening phases (i.e., group BB, LL, and FF). For the other 4 dietary groups, the fatty acid source was switched after the first phase (groups BL, BF, LF, and FL; the first and second letter indicating the diet in P1 and P2, respectively). Twelve animals per feeding group were selected based on average live BW. The LT was analyzed for fatty acid composition; lipid stability (thiobarbituric acid-reactive substances) and color stability (a* value, % of myoglobin pigments) were determined on the LT after illuminated chill storage for up to 8 d. The alpha-linolenic acid, EPA, and docosapentaenoic acid incorporation was independent of the duration of linseed feeding (1.24, 0.54, and 0.75% of total fatty acids, respectively, for group LL). Supplying fish oil during both phases resulted in the greatest EPA and DHA proportions (1.37 and 1.02% of total fatty acids; P < 0.05), but the content of docosapentaenoic acid was not affected. The proportion of DHA was greater when fish oil was administered during P2 compared with P1 (P < 0.05). There was no effect of diet on meat ultimate pH and drip loss or on lipid or color oxidation.

Decreasing the dietary n‐6/n‐3 fatty acid ratio uniquely increases eicosapentaenic acid in heart membrane phospholipids with no effect on GLUT 4 expression in piglets

The omega 3 fatty acids (FA), alpha linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) are associated with decreased cardiovascular (CVD) and inflammatory disease. The omega 6 linoleic acid (LA, 18:2n-6) has favorable effects on CVD through effects on plasma lipids. However, high intakes of LA may inhibit ALA metabolism to EPA and DHA, resulting in decreased tissue n-3 FA and increased arachidonic acid (ARA, 20:4n-6) to EPA ratios. N-6 and n-3 FA also regulate expression of genes for proteins of FA and glucose metabolism, and in skeletal muscle n-3 FA increase GLUT 4 expression, thus favoring glucose oxidation. The effect of dietary LA/ALA ratio on heart phospholipid (PL) FA and GLUT 4 expression is not known. We determined the effect of dietary n-6 and n-3 FA on heart membrane phospholipid FA and GLUT 4 expression. Piglets were fed (%energy) 1.5% LA+0.06% ALA, 1.5% LA+1.2% ALA, 9% LA+1.2% ALA, or 9% LA+1.2% ALA with 0.6% ARA+0.8% DHA for 30 days. Membrane PL and FA were determined by HPLC and GLC. GLUT 4 membrane and cytosol expression and distribution was determined by Western blot. Piglets fed 1.5%LA+1.2%ALA had higher EPA and lower ARA and ARA/EPA in all heart PL compared to the other diets, demonstrating the LA/ALA ratio, not ALA intake determines EPA incorporation. Regardless of the difference in membrane FA, we found no difference in GLUT 4 expression.

Lipase‐catalyzed incorporation of n−3 PUFA into palm oil

AbstractTwo immobilized lipases, IM60 from Rhizomucor miehei and QLM from Alcaligenes sp., were used as biocatalysts for the modification of the FA composition of palm oil by incorporating n−3 PUFA. Acidolysis and interesterification reactions were conducted with hexane as organic solvent, and the products were analyzed by using GLC. After a 24‐h incubation in hexane, there was an average incorporation of 20.8% EPA and 15.6% DHA into palm oil, respectively, while the percentages of palmitic and oleic acids in palm oil decreased by 28.8 and 11.8%, respectively. Higher EPA and DHA incorporation was obtained when EPAX (fish oil concentrate high in n−3 PUFA) was used in the ethyl ester form (interesterification reaction) than in the free acid form (acidolysis) in the presence of Lipozyme (IM60 lipase. Lipase QLM was found to discriminate against EPA, and it showed slightly better catalytic activity for DHA in the free acid form than in the ethyl ester form. Generally, as the mole ratio of the acyl donor to TAG increased, the percentage incorporation of EPA and DHA increased; however, reactions catalyzed by Lipozyme IM60 did not show increases in the incorporation beyond a TAG/EPAX mole ratio of 3. When limitations due to mass transfer were not a factor, an increase in the reactant amount also gave an increase in the percentage incorporation of the n−3 PUFA. Palm oil containing EPA and DHA was successfully produced and may be beneficial in certain food and nutritional applications.

Dietary n-3 PUFA alter colonocyte mitochondrial membrane composition and function.

There is experimental evidence that dietary fish oil, which contains the n-3 fatty acid family, i.e., EPA and DHA, protects against colon tumor development, in part by increasing apoptosis. Since mitochondria can act as central executioners of apoptosis, we hypothesized that EPA and DHA incorporation into colonocyte mitochondrial membranes, owing to their high degree of unsaturation, would enhance susceptibility to damage by reactive oxygen species (ROS) generated via oxidative phosphorylation. This, in turn, would compromise mitochondrial function, thereby initiating apoptosis. To test this hypothesis, colonic crypts were isolated from rats fed either fish oil, purified n-3 fatty acid ethyl esters, or corn oil (control). Dietary lipid source had no effect on colonic mitochondrial phospholipid class mole percentages, although incorporation of EPA and DHA was associated with a reduction in n-6 fatty acids known to enhance colon tumor development, i.e., linoleic acid LNA) and its metabolic product, arachidonic acid (ARA). Select compositional changes in major phospholipid pools were correlated to alterations in mitochondrial function as assessed by confocal microscopy. The mol% sum of LNA plus ARA in cardiolipin was inversely correlated with ROS (P = 0.024). Ethanolamine glycerophospholipid ARA (P = 0.046) and choline glycerophospholipid LNA (P = 0.033) levels were positively correlated to mitochondrial membrane potential. In contrast, ethanolamine glycerophospholipid EPA (P = 0.042) and DHA (P = 0.024) levels were negatively correlated to mitochondrial membrane potential. Additionally, EPA and DHA levels in choline glycerophospholipids (P = 0.026) were positively correlated with caspase 3 activity. These data provide evidence in vivo indicating that dietary EPA and DHA induce compositional changes in colonic mitochondrial membrane phospholipids that facilitate apoptosis.

Structured lipids via lipase-catalyzed incorporation of eicosapentaenoic acid into borage (Borago officinalis L.) and evening primrose (Oenothera biennis L.) oils.

Enzymatic acidolysis of borage oil (BO) or evening primrose oil (EPO) with eicosapentaenoic acid (20:5n-3; EPA) was studied. Of the six lipases that were tested in the initial screening, nonspecific lipase PS-30 from Pseudomonas sp. resulted in the highest incorporation of EPA into both oils. This enzyme was further studied for the influence of enzyme load, temperature, time, type of organic solvent, and mole ratio of substrates. The products from the acidolysis reaction were analyzed by gas chromatography (GC). The highest incorporation of EPA in both oils occurred at 45-55 degrees C and at 150-250 enzyme activity units. One unit of lipase activity was defined as nanomoles of fatty acids (oleic acid equivalents) produced per minute per gram of enzyme. Time course studies indicated that EPA incorporation was increased up to 26.8 and 25.2% (after 24 h) in BO and EPO, respectively. Among the solvents examined, n-hexane served best for the acidolysis of EPA with both oils. The effect of the mole ratio of oil to EPA was studied from 1:1 to 1:3. As the mole ratio of EPA increased, the incorporation increased from 25.2-26.8 to 37.4-39.9% (after 24 h). The highest EPA incorporations of 39.9 and 37.4% in BO and EPO, respectively, occurred at the stoichiometric mole ratio of 1:3 for oil to EPA.

Dietary effect of a symmetrical triacylglycerol, 1,3‐biseicosapentaenoyl‐2‐γ‐linolenoyl glycerol, on fatty acid composition of guinea pigs

The dietary effect of 1,3-biseicosapentaenoyl-2-gamma-linolenoyl glycerol (STG) on the fatty acid composition of guinea pigs was examined and compared with that of an eicosapentaenoic acid ethyl ester (EPA-E) and of a soybean oil (SBO) diet. In terms of content of plasma lipid, EPA-E had a greater hypolipidemic effect than STG. On the other hand, in terms of EPA incorporation, contents of EPA in liver lipid were almost the same in the STG and EPA-E groups. Considering that the amount of EPA administered in the EPA-E group was almost 1.5 times that of the STG group, EPA may be absorbed more effectively as the glycerol ester than as the ethyl ester in guinea pigs. In all the tissue lipids, the STG group had a higher unsaturation index (UI) than the EPA-E group even though there is a lower UI in the STG diet than the EPA-E diet. These results suggest that greater amounts of desaturase products as a whole were synthesized in the STG group than in the other two groups. The dihomo-gamma-linolenic acid/arachidonic acid (DGLA/AA) ratio in plasma total lipids in the STG group was 3.5 times that of SBO group, and the DGLA/AA ratio in the EPA-E group was half that of the SBO group. In liver lipid, the ratios of DGLA/AA and EPA/AA in the STG group were 0.687 and 0.488 (phosphatidylcholine fraction) and 0.237 and 0.752 (phosphatidylethanolamine fraction), respectively. The ratio of DGLA/AA as well as the high EPA/AA ratio obtained in the present study with the STG diet may lead to physiological alterations, including enhanced synthesis of 1- and 3-series eicosanoids.

Erythrocyte eicosapentaenoic acid versus docosahexaenoic acid as a marker for fish and fish oil consumption

The fatty acid composition of erythrocyte membranes was investigated in 21 healthy men after 6 wk of varying intakes of eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). In one experiment, 12 subjects were fed three diets in a 3 × 3 crossover design: an essentially fish-free control diet, a fish diet (0.15 g EPA/d, 0.41 g DHA/d) and the same fish-based diet supplemented with 5 g/d fish oil (Fish + Oil: 0.99 g EPA/d, 0.99 g DHA/d). A 6 wk wash-out period was allowed between each diet. In another experiment, 11 subjects were supplemented with 5 g/d fish oil alone for 6 wk (0.84 g EPA/d, 0.48 g DHA/d). After fish or fish oil feeding, the percent proportion of EPA and DHA in the erythrocyte membranes rose at the expense of linoleic and arachidonic acids. After 6 wk on the fish-based diets, EPA incorporation approached saturation, with the incremental increases being proportional to the amounts supplied by the diets. In contrast, parallel increases were observed for erythrocyte DHA even though the Fish + Oil diet was supplying twice as much DHA as the fish alone diet. These observations imply different metabolic rates for EPA and DHA and their importance is discussed in terms of the value of erythrocyte EPA versus DHA as markers for fish and fish oil consumption.

Eicosapentaenoic acid ethyl ester as an antithrombotic agent: comparison to an extract of fish oil

Evidence suggesting that dietary ω-3 polyunsaturated fatty acids decrease the risk of thrombosis comes mainly from studies involving supplementation with large amounts (15–20 g/day) of fish oil extract. We investigated the inhibition of platelet function by a moderate amount (4 g/d) of ethyl eicosapentaenoate (E-EPA) compared to a concentrated fish oil extract (6 g/d) when given as a supplement to an ordinary diet. We also determined the effects of these supplements on platelet EPA incorporation, thromboxane synthesis, calcium mobilization and fibrinogen binding. After 4 weeks, both ω-3 supplements increased the amount of EPA in platelet phospholipids. The fish oil extract, which contained docosahexaenoic acid (DHA), had increased the amount of DHA also. The total increase in ω-3 fatty acids was similar for both supplements. E-EPA decreased serum cholesterol by 13% and triacylglycerols, 35%; increased the bleeding time by 57% and the threshold dose of collagen needed to induce platelet aggregation by 46%. Thromboxane synthesis in response to collagen was decreased 65% by E-EPA. Thus, the dietary supplement of pure E-EPA was more effective in limiting platelet reactivity than a concentrated fish oil extract providing an equivalent amount of ω-3 fatty acids. As an antithrombotic agent, E-EPA should allow for reasonable daily dosis in long-term treatment of cardiovascular disease.

Incorporation and effects of dietary eicosapentaenoate (20 : 5( n − 3)) on plasma and erythrocyte lipids of the marmoset following dietary supplementation with differing levels of linoleic acid

The effect of dietary eicosapentaenoic acid (EPA, 20:5( n − 3), as the ethyl ester) on plasma lipid levels and the incorporation of EPA into erythrocyte and plasma lipids were investigated in the marmoset monkey. Marmosets were fed high mixed-fat diets (14.5% total fat) supplemented with or without 0.8% EPA for 30 weeks. Markedly elevated plasma cholesterol (16.4 nunol/l) was induced by an atherogenic-type diet but with EPA supplementation, plasma cholesterol increased to only 6.6 nunol/l. Plasma triacylglycerol levels were not elevated with an atherogenic type diet. Substantial EPA incorporation was evident for plasma phospholipid, triacylglycerol and cholesterol ester fractions. The proportion of docosapentaenoic acid (22:5( n − 3)) but not docosahexaenoic acid (22:6( n − 3)) was also elevated in these plasma lipid fractions. Greatest incorporation of EPA occurred when it was administered with an atherogenic type diet having a P: M: S (polyunsaturated: monounsaturated: saturated) fatty acid ratio of about 0.2:0.6:1.0 in comparison to the control diet of 1.0:1.0:1.0. Incorporation of EPA and 22:5 n − 3) into erythrocyte phospholipids was also apparent and this was at the expense of linoleic acid (18:2( n − 6)). These results in the marmoset highlight both the cholesterol-lowering properties of EPA and the extent of its incorporation into plasma lipids and erythrocyte membrane phospholipids with far greater incorporation occurring when the level of dietary linoleic acid was reduced.

Modification of Sardine Oil by Immobilized Bacterial Lipase

Determination was made of the rates of icosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) incorporation into triolein and sardine oil triglyceride (TG).Three kinds of lipases (Lipase OF from Candida cyrindracea, Lipase A from Aspergillus sp. and Lipase TOYO from Chromobacterium viscosum) were first immobilized onto Celite 545. A preliminary study was then performed to determine optimum conditions for acidolysis by conducting this process between triolein and palmitic acid, using these immobilized lipases including LipozymeTH (Mucor miehei lipase was immobilized on a macroporous anion exchange resin). Optimum water contents for Lipase OF, Lipase A, Lipozyme, and Lipase TOYO reaction systems were 20.38%, 10.24%, 6.3810.38%, and 5.18%, respectively, and the optimum immobilized lipase amount was about 250 mg for any of the four lipases.Under the above conditions, the acidolysis of triolein between pure EPA and then DHA was carried out. EPA incorporation rate was found highest in the system using Lipase OF (25.09%), whereas in the case of DHA, it was highest in the system using Lipase TOYO (23.02%).Finally, acidolysis of sardine oil TG with an EPA, DHA concentrated free fatty acid mixture (EPA+DHA : 68.83%) was carried out and the results examined.As a result of the low incorporation rates of EPA and DHA into the original sardine oil TG, the percentage of DHA in the reactant TG doubled in the reaction systems using Lipase TOYO and Lipozyme.