High Levels Of Docosahexaenoic Acid Research Articles

Proteomic Analysis of the Effect of DHA-Phospholipids from Large Yellow Croaker Roe on Hyperlipidemic Mice.

Previously, we found that phospholipids derived from large yellow croaker (Pseudosciaena crocea) roe had a higher level of docosahexaenoic acid (DHA-PL), which had beneficial effects on lipid metabolism. However, the mechanism by which DHA-PL from P. crocea roe exerts these effects has not yet been illuminated. Herein, we investigated the underlying molecular action of DHA-PL by examining changes in liver protein expression in control, hyperlipidemic, and DHA-PL-treated mice. A total of 16 proteins, 9 up-regulated and 7 down-regulated, were identified and classified into several metabolic pathways, such as fat digestion and absorption, peroxisome proliferator activated receptor (PPAR) signaling, and antigen processing and presentation; the largest functional class found was that of fat digestion and absorption. We revealed Apoa1 to be a biomarker of DHA-PL effects on hyperlipidemic mice by DHA-PL diet. These results not only improve our current understanding of hyperlipidemic regulation by DHA-PL, but also suggest that DHA-PL should be applied as a beneficial food additive.

Development of a docosahexaenoic acid (DHA)-rich yellowtail Seriola quinqueradiata using tuna by-product oil

Because a diet rich in docosahexaenoic acid (DHA) is beneficial to human health, it is desirable for yellowtail Seriola quinqueradiata intended for human consumption to contain a high amount of DHA. We investigated the effects on the growth and fatty acid composition of yellowtail of replacing some of the pollack liver oil (PO) in the yellowtail diet with a DHA-rich tuna oil (TO). Experimental diets were prepared in which PO was replaced with 0, 15, 30, and 60% TO. Replacement of PO with TO did not negatively affect growth in a 16-week trial. In contrast, the feed efficiency of the group that received 60% TO was significantly higher than that of the control group after 6 weeks. The DHA level in the whole fish body increased with increasing dietary TO level. The groups that received 30 and 60% TO replacement diets showed significantly higher DHA levels than those of the control group. DHA level in the fillet was significantly higher in the group that received 60% TO than in the control group. DHA retention tended to increase with increasing TO level. These results show that utilizing TO as a fat source can increase DHA accumulation without incurring any adverse effects on the growth of yellowtail.

Ketoacylsynthase Domains of a Polyunsaturated Fatty Acid Synthase in Thraustochytrium sp. Strain ATCC 26185 Can Effectively Function as Stand-Alone Enzymes in Escherichia coli.

Thraustochytrium sp. strain ATCC 26185 accumulates a high level of docosahexaenoic acid (DHA), a nutritionally important ω-3 very-long-chain polyunsaturated fatty acid (VLCPUFA) synthesized primarily by polyunsaturated fatty acid (PUFA) synthase, a type I polyketide synthase-like megaenzyme. The PUFA synthase in this species comprises three large subunits, each with multiple catalytic domains. It was hypothesized that among these domains, ketoacylsynthase (KS) domains might be critical for catalyzing the condensation of specific unsaturated acyl-acyl carrier proteins (ACPs) with malonyl-ACP, thereby retaining double bonds in an extended acyl chain. To investigate the functions of these putative KS domains, two segment sequences from subunit A (KS-A) and subunit B (KS-B) of the PUFA synthase were dissected and then expressed as stand-alone enzymes in Escherichia coli The results showed that both KS-A and KS-B domains could complement the defective phenotypes of both E. colifabB and fabF mutants. Overexpression of these domains in wild-type E. coli led to increases in total fatty acid production. KS-B produced a higher ratio of unsaturated fatty acids (UFAs) to saturated fatty acids (SFAs), while KS-A could improve the overall production of fatty acids more effectively, particularly for the production of SFAs, implying that KS-A is more comparable to FabF, while KS-B is more similar to FabB in catalytic functions. Successful complementation and functional expression of the embedded KS domains in E. coli are the first step forward in studying the molecular mechanism of the PUFA synthase for the biosynthesis of VLCPUFAs in ThraustochytriumIMPORTANCE Very-long-chain polyunsaturated fatty acids (VLCPUFAs) are important for human health. They can be biosynthesized in either an aerobic pathway or an anaerobic pathway in nature. However, abundant VLCPUFAs in marine microorganisms are primarily synthesized by polyunsaturated fatty acid (PUFA) synthase, a megaenzyme with multiple subunits, each with multiple catalytic domains. Furthermore, the fundamental mechanism for this enzyme to synthesize these fatty acids still remains unknown. This report started with dissecting the embedded KS domains of the PUFA synthase from marine protist Thraustochytrium sp. strain ATCC 26185 and then expressing them in wild-type E. coli and mutants defective in condensation of acyl-ACP with malonyl-ACP. Successful complementation of the mutants and improved fatty acid production in the overexpression experiments indicate that these KS domains can effectively function as stand-alone enzymes in E. coli This result has paved the way for further studying of molecular mechanisms of the PUFA synthase for the biosynthesis of VLCPUFAs.

Highly efficient extraction of EPA/DHA‐enriched oil from cobia liver using homogenization plus sonication

Cobia, Rachycentron canadum, is a species of marine finfish with emerging global potential for offshore aquaculture. The fillet processing by‐product, cobia liver, can be considered an accessible source of EPA/DHA‐enriched oil. Oils are mainly extracted with hexane in the oil industry; however, extractability is greatly decreased in wet biomass as the hydrophilic surface hinders the penetration of hexane into the tissue matrix. In this study, the feasibility of agitated extraction (AE), ultrasonic extraction (UE), Soxhlet extraction (SE), homogenizer extraction (HE), and homogenizer extraction plus sonication (HES) was evaluated. HE and HES showed higher extraction efficiency than AE, UE, or SE. The highest yields: 45.7% and 50.2%, were obtained from using HE for 2 min and HES for 120 min, respectively. Both yields were close to the fat content of cobia liver, indicating that the lipids were effectively extracted. The fatty acid profiles revealed that the highest contents of 5.2% eicosapentaenoic acid (EPA) and 19.7% docosahexaenoic acid (DHA) were obtained from HE and HES, respectively. These results demonstrated that HE and HES were highly efficient and the most useful among all tested methods for lipid extraction from wet biomass.Practical applications: Increasing the value of low quality processing waste is important in the food and nutraceutical industries. Cobia liver, comprising 5% of total fish mass, is a potential source of EPA/DHA‐enriched fish oil. EPA and DHA decompose easily when exposed to high temperatures for a long time. HE has an advantage over traditional extraction methods due to its ability to operate at a low temperature for a short period (2 min), thereby preventing EPA and DHA decomposition. Cobia are already bred in the aquaculture industry; their livers are readily available by‐products obtained after fillet processing. The oils extracted from cobia liver have high levels of EPA and DHA, therefore it is an excellent raw material to produce EPA/DHA‐enriched oil.Wet biomass contains a high amount of moisture, creating mass transfer resistance for hexane penetration into the tissue matrix. Homogenizer extraction grinds the tissue matrix, disrupting the cell and dispersing the water into solvent phase. Schematic representation of the extent of cell disruption during homogenizer extraction shows its effect on the rate of lipid release.

Docosahexaenoic acid enrichment in NAFLD is associated with improvements in hepatic metabolism and hepatic insulin sensitivity: a pilot study

Background/Objective:Treatment of subjects with non-alcoholic fatty liver disease (NAFLD) with omega-3 polyunsaturated fatty acids (FAs) suggests high levels of docosahexaenoic acid (DHA) tissue enrichment decrease liver fat content. We assessed whether changes in erythrocyte DHA enrichment (as a surrogate marker of changes in tissue enrichment) were associated with alterations in hepatic de novo lipogenesis (DNL), postprandial FA partitioning and hepatic and peripheral insulin sensitivity in a sub-study of the WELCOME trial (Wessex Evaluation of fatty Liver and Cardiovascular markers in NAFLD (non-alcoholic fatty liver disease) with OMacor thErapy).Subjects/Methods:Sixteen participants were randomised to 4 g/day EPA+DHA (n=8) or placebo (n=8) for 15–18 months and underwent pre- and post-intervention measurements. Fasting and postprandial hepatic FA metabolism was assessed using metabolic substrates labelled with stable-isotope tracers (2H2O and [U13C]palmitate). Insulin sensitivity was measured by a stepped hyperinsulinaemic-euglycaemic clamp using deuterated glucose. Participants were stratified according to change in DHA erythrocyte enrichment (< or ⩾2% post intervention).Results:Nine participants were stratified to DHA⩾2% (eight randomised to EPA+DHA and one to placebo) and seven to the DHA<2% group (all placebo). Compared with individuals with erythrocyte <2% change in DHA abundance, those with ⩾2% enrichment had significant improvements in hepatic insulin sensitivity, reduced fasting and postprandial plasma triglyceride concentrations, decreased fasting hepatic DNL, as well as greater appearance of 13C from dietary fat into plasma 3-hydroxybutyrate (all P<0.05).Conclusions:The findings from our pilot study indicate that individuals who achieved a change in erythrocyte DHA enrichment ⩾2% show favourable changes in hepatic FA metabolism and insulin sensitivity, which may contribute to decreasing hepatic fat content.

Fatty acid composition and docosahexaenoic acid (DHA) content of the heterotrophic dinoflagellate Oxyrrhis marina fed on dried yeast: compared with algal prey

The heterotrophic dinoflagellate Oxyrrhis marina is known to produce high levels of docosahexaenoic acid (DHA) when fed on diverse algal prey. However, large-scale culturing of algal prey species is not easy and requires a large amount of budget, and thus more easily cultivable and low-cost prey is required. Dried yeast was selected as a strong candidate for an alternative prey in our preliminary tests. Thus, we explored the fatty acid composition and DHA production of O. marina fed on dried yeast and compared these results to those of O. marina fed on two algal prey species: the phototrophic dinoflagellate Amphidinium carterae and chlorophyte Chlorella sp. powder. O. marina fed on dried yeast, which does not contain DHA, produced the same high level of DHA as those fed on DHA-containing A. carterae. This indicates that O. marina is likely to produce DHA by itself regardless of prey items. Furthermore, the DHA content (and portion of total fatty acid methyl esters) of O. marina satiated with dried yeast, 52.40 pg per cell (and 25.9%), was considerably greater than that of O. marina fed on A. carterae (26.91 pg per cell; 15.7%) or powder of Chlorella sp. powder (21.24 pg per cell; 16.7%). The cost of dried yeast (approximately 10 US dollars for 1 kg dried yeast) was much lower than that of obtaining the algal prey (approximately 160 US dollars for 1 kg A. carterae). Therefore, compared to conventional algal prey, dried yeast is a more easily obtainable and lower-cost prey for use in the production of DHA by O. marina. Key words: Amphidinium carterae; Chloroella; DHA production; feeding; lipid; low-cost prey; omega-3

Lipid correlates of antidepressant response to omega-3 polyunsaturated fatty acid supplementation: A pilot study

Low omega-3 polyunsaturated fatty acid (PUFA) levels are seen in major depression. We examined effects of six weeks of fish oil supplementation on clinical characteristics in 16 patients with symptomatic major depressive disorder, and tested plasma phospholipid levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) as correlates of clinical response. Depression symptoms improved after supplementation (p=0.007). The reduction in depression severity was not predicted by baseline PUFA levels but did exhibit a relationship with endpoint PUFAs, correlating negatively with DHA as a percentage of plasma phospholipids (DHA%; R2=0.60, p=0.004), adjusting for endpoint EPA%; and correlating positively with endpoint EPA% (R2=0.58, p=0.007), adjusting for endpoint DHA%. Thus, the higher the proportion of DHA to EPA, the greater the reduction in depression severity (r=−0.43, p=0.097). Five patients showed a decrease of >50% on the 17-item Hamilton Depression Rating Scale and a final score <7 and were thus not only responders but met standard criteria for remission, and were distinguished from non-responders by higher levels of DHA% (p=0.03). This pilot study suggests that post-supplementation DHA% levels may be a necessary target for antidepressant response to fish oil, and that this may depend to some extent on the efficacy of EPA conversion to DHA.

Effects of Essential Fatty Acids Containing Natural and Commercial Diets on Larvae Rearing of the Green Mud Crab &lt;i&gt;Scylla Paramamosain&lt;/i&gt; (Estampador 1949)

Effect of essential fatty acids (EFA) on growth and survival of the green mud crab (Scylla paramamosain) larvae was assessed by feeding with natural to commercial diets. The feeding schemes were: larvae reared with Artemia (T1); larvae initially fed with rotifers (up to Z2) and ended (Z3 to megalopa) with Artemia (T2); and larvae fed with rotifers up to Z2 and ended (Z3 to megalopa) with commercial diet (T3). The commercial diet had significantly (p&lt;0.05) higher levels of docosahexaenoic acid (11.23%), ?n-3’s (15.90%) and ?n-6’s (4.21%); and lacked in eicosapentaenoic acid (2.25%) than rotifer and Artemia. The earliest commencement of megalopa stage within 15 days with significantly (p&lt;0.05) higher larval stage index (LSI) of 5.90±0.17 was achieved from the feeding scheme of T2 than other two feeding schemes. This feeding scheme deposited 17.32±0.19% eicosapentaenoic acid (EPA) and 3.82±0.11% docosahexaenoic acid (DHA); the ?n-3 to ?n-6 ratio of 0.20 and EPA to DHA ratio of 0.22 in megalopa, that stimulated significantly higher (p&lt;0.05) megalopa survival (20.00±6.96%) indicating the superiority over rest feeding schemes. Meanwhile, some deformities and mortalities in Z5 and megalopa stages suggested further studies for optimization of specific fatty acid requirements for late larval stages (Z5 and megalopa).

Growth phase significantly decreases the DHA-to-EPA ratio in marine microalgae

Microalgae are the principal producers of long-chain polyunsaturated fatty acids (LC-PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in marine ecosystems. Algae are used in aquaculture systems as direct or indirect feed for zooplankton, filter-feeding mollusks and larval stages of crustaceans and fish. Therefore, it is necessary to select nutrient-rich strains, with high levels of EPA and/or DHA, preferably during the stage of rapid growth. During the course of algal growth (exponential to stationary phase), many microalgal species accumulate lipids, especially triacylglycerols. However, relatively little is known about the effect of growth phase on LC-PUFA accumulation. In the present study, absolute and relative EPA and DHA levels of seven representative species of marine microalgae were determined during different growth phases in batch culture. Four species (Phaeodactylum tricornutum, Thalassiosira weissflogii, Thalassiosira pseudonana and Rhodomonas salina) accumulated fatty acids during growth. In all these species, intracellular EPA levels were higher during the late stationary growth phase than during exponential growth. In contrast, an increase in DHA content was not observed and therefore the DHA-to-EPA ratio was significantly lower in late stationary phase cultures. These results can be used to improve the nutritional value of microalgae cultivated for application in marine aquaculture systems.

Fatty acid composition and age estimation of wild Octopus vulgaris paralarvae

The fatty acid (FA) profile of wild Octopus vulgaris paralarvae of estimated age was individually analyzed for the very first time in order to establish a reference for comparison in rearing and nutritional studies. Age of each paralarvae was estimated by analysing daily increments on lateral hood surface of beaks. Wild paralarvae age ranged between 6 and 8days and their FA composition resembled that from hatchlings produced under culture conditions. However, when compared with the FA composition of up to 20days old cultured paralarvae described in the bibliography, some striking differences were found. Results showed higher levels of docosahexaenoic acid (22:6n−3, DHA), lower contents of 18:1n−9, 18:1n−7 and 18:2n−6 and negligible levels of 18:3n−3 in wild paralarvae, when collated to reared one. These results seem to indicate that preys/diets supplied to cultured paralarvae fail to resemble paralarval natural composition and as a result do not fulfil their FA requirement. The individual applied technique developed in this study will allow to refine the study of wild paralarvae along its development, as well as to compare wild and cultured paralarvae of similar age. Statement of relevanceArtemia does not fulfil paralarval fatty acid requirements.

Mercury diminishes the cardiovascular protective effect of omega-3 polyunsaturated fatty acids in the modern diet of Inuit in Canada

BackgroundInuit in Canada have low reported incidence of myocardial infarction (MI) because of their traditional rich n-3 fatty acids marine diet. They are experiencing rapid nutrition transition and ischemic heart disease is now becoming a health concern. ObjectivesOur goal was to describe the modern Inuit diet, the eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and methyl mercury (MeHg) intake and estimate their contributions to the risk of MI. We also estimated the effect of promoting the consumption of more traditional food on Inuit's MI risk. MethodsWe estimated the effect of Inuit diet on MI risk with modelling. Model formulas and assumptions were extracted from various epidemiology studies and literatures. International Polar Year Inuit Health Survey (IHS) was a comprehensive health and nutrition survey conducted in 2007–8 with 2072 participants (aged 18–79) in Canada. Traditional food intake, blood biomarkers values from the IHS served as the baseline parameters of model input. ResultsInuit traditional diet contained both high level of EPA, DHA and MeHg and their combined net effect was estimated to reduce the relative risk of MI by 1% for men and 2% for women. Arctic char meat provided the largest amount of EPA and DHA. Ringed seal liver was the main source for MeHg. Increase intake of selected fish, like salmon, herring and Arctic char by 75g per day can reduce the relative risk of MI (RR 0.70, 0.78 and 0.90 respectively). ConclusionsIn the Inuit diet, the beneficial effect on MI of EPA and DHA is diminished by the adverse effect of MeHg. Promoting the increase consumption of fish species with high EPA+DHA and low MeHg may help to prevent MI among Inuit.

Attenuation of EPA and DHA‐Mediated Platelet Inhibition Effects Following Heterogeneous Agonist Treatment

Agonist‐induced platelet activation following vascular damage is a critical event for the propagation of thrombi formed as a part of either hemostasis or thrombosis. Several studies have indicated this activation can be impaired after platelet membrane enrichment with the polyunsaturated omega‐3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This attenuated platelet function represents a potential mechanism behind the anti‐thrombotic benefits of EPA and DHA observed in many human trials. However, nearly all platelet studies with EPA and DHA examined the alterations to platelet activation in response to a single agonist, rather than with multiple agonists that mimic the more complex heterogeneous environment of a developing arterial clot. We therefore asked if high levels of EPA and DHA could still inhibit platelet activation if platelets were stimulated with a combination of agonists designed to simulate the activating conditions found in the thrombus inner core (using thrombin and collagen) or outer shell (using ADP and thromboxane A2). To test this question, we treated platelets with EPA and DHA concentrations in vitro that raise the membrane content of both fatty acids to levels analogous to subjects taking EPA and DHA supplements. After this modification, the platelets were stimulated with the agonist combinations and measured for an activation response. Surprisingly, inherent measures of platelet activation using these agonist combinations, including adhesion, aggregation, granule release, and integrin activation were either only mildly affected or non‐significantly altered after EPA and DHA membrane enrichment. We also tested the ability of the core agonist combination to stimulate platelet‐derived thrombin generation, a catalytic process thought to be necessary for rapid thrombus core development. Contrary to the other measures of platelet function, thrombin generation was still consistently impaired by elevated EPA and DHA levels. We conclude that elevated levels of EPA and DHA in the developing clot environment do not readily inhibit most events of platelet activation. Instead, the impairment of amplified thrombin generation in the platelet‐rich arterial clot may provide a more likely candidate for how EPA and DHA prevent detrimental cardiovascular events.Support or Funding InformationResearch reported in this abstract was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103443, a South Dakota/National Science Foundation EPSCoR RII Track 1 grant, the Sanford Program for Undergraduate Research, and an American Physiological Society Undergraduate Summer Research Fellowship.

Rotifers enriched with a mixed algal diet promote survival, growth and development of barramundi larvae, Lates calcarifer (Bloch)

Fulfilling the nutritional requirements of marine fish larvae, including barramundi (Lates calcarifer), remains a bottleneck for optimal commercial hatchery production. This study investigated the effect of mixed algal diets for the enrichment of rotifers on the survival, growth, development and stress resistance of barramundi larvae. Four groups of 2–13 days-post-hatch (dph) barramundi larvae were fed rotifers enriched with either Nannochloropsis oculata, Chlorella vulgaris, or a blend of 50:50 or 75:25 of N. oculata to C. vulgaris (based on dry weight, DW), respectively. The highly unsaturated fatty acids (HUFAs) docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA) were used as qualitative proxies of the feed. The barramundi larvae fed with the 50:50 diet outperformed all other treatments, with significantly greater larval length (P<0.05), eye diameter (P<0.05) and body depth (P<0.05) at 10 dph, a trend conserved over the whole growth period. The barramundi larvae fed the 50:50 diet also achieved the highest flexion percentage at 10 dph (P<0.05) and scored the highest survival past the stress test (85%; P<0.05). The best performing treatment had the second highest level of DHA which suggests that while DHA is an important fatty acid for barramundi larvae it is likely its interaction with other EFA and monounsaturated fatty acid also plays a critical role in their development. Overall, blending microalgae species can enhance the balance of dietary fatty acid for barramundi larvae which in turn can lead to better growth, faster development and higher stress resistance when compared to monospecific microalgal diets.

Should there be a target level of docosahexaenoic acid in breast milk?

This article examines the evidence for and against establishing a target level of docosahexaenoic acid (DHA) in breast milk. Two target levels for milk DHA have been recently proposed. One (∼0.3% of milk fatty acids) was based on milk DHA levels achieved in women consuming the amount of DHA recommended by the American Academy of Pediatrics for pregnant and lactating women (at least 200 mg DHA/day). Another (∼1.0%) was based on biomarker studies of populations with differing lifelong intakes of fish. Populations or research cohorts with milk DHA levels of 1.0% are associated with intakes that allow both the mother and infant to maintain relatively high DHA levels throughout lactation. Lower milk DHA levels may signal suboptimal maternal stores and possibly suboptimal infant intakes. Based on the current data, a reasonable milk DHA target appears to be approximately 0.3%, which is about the worldwide average. Although this may not be the 'optimal' level (which remains to be defined), it is clearly an improvement over the currently low milk DHA levels (∼0.2%) seen in many Western populations.

Baseline blood levels of omega-3 and depression remission: a secondary analysis of data from a placebo-controlled trial of omega-3 supplements.

Depression is associated with low red blood cell (RBC) levels of 2 omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), suggesting that omega-3 supplements might improve depression. However, clinical trials have produced mixed results. The purpose of this secondary analysis of data from a randomized controlled trial was to determine whether baseline blood levels of omega-3, which are known to vary widely among individuals, predict depression outcomes. The percentages of EPA, DHA, and the omega-6 arachidonic acid (AA) were measured in RBCs at baseline and posttreatment in 122 participants with DSM-IV major depression who were randomly assigned between May 2005 and December 2008 to receive either 50 mg/d of sertraline and a daily dosage of 930 mg EPA/750 mg DHA or sertraline plus placebo. Associations between baseline omega-3 RBC levels and remission of depression (17-item Hamilton Depression Rating Scale score ≤ 7) were analyzed by treatment arm. Among participants in the omega-3 arm, baseline RBC levels of EPA + DHA (P = .002) and the EPA + DHA:AA ratio (P = .003) were significantly higher among those whose depression subsequently remitted compared with those whose depression did not remit. No associations were detected in the sertraline plus placebo arm. Baseline levels of EPA (P = .03) and the EPA + DHA:AA ratio (P = .04) moderated the relationship between treatment arm and depression outcomes. High baseline RBC levels of EPA and DHA and a high EPA + DHA:AA ratio predict favorable depression outcomes in patients receiving omega-3 supplements. Omega-3 supplementation may be an effective treatment for depression, but the requisite dosage and duration of treatment may depend on the patient's baseline level of omega-3 fatty acids. ClinicalTrials.gov identifier: NCT00116857.

Immobilized phospholipase A1-catalyzed acidolysis of phosphatidylcholine from Antarctic krill (Euphausia superba) for docosahexaenoic acid enrichment under supercritical conditions

This paper describes the use of immobilized phospholipase A1 (PLA1) for the production of phosphatidylcholine (PC) rich in docosahexaenoic acid (DHA) using PC from Antarctic krill and fish fatty acids (FA) as the substrates, and supercritical carbon dioxide (SCCO2) as the solvent medium. Detailed studies of immobilization were performed, and PLA1 was immobilized by physical adsorption onto DA-201. The best conditions for adsorption were as follows: protein loading=85mg PLA1/g support at a pH of 5 with 10h of contact. For synthesis of PC with high levels of DHA, the effects of several parameters, including pressure, reaction time, temperature, enzyme loading and substrate molar ratio, were investigated to determine optimal conditions. The optimal substrate molar ratio of the FA to PC was 10. Under 12MPa and 50°C SCCO2, 59.0mol% DHA was incorporated into PC after only 7h at an immobilized enzyme loading rate of 15wt% of the total substrates. The PC yield was 27.5mol% under the optimal conditions.

Early and gender-specific differences in spinal cord mitochondrial function and oxidative stress markers in a mouse model of ALS.

IntroductionAmyotrophic lateral sclerosis (ALS) is a motor neuron disease with a gender bias towards major prevalence in male individuals. Several data suggest the involvement of oxidative stress and mitochondrial dysfunction in its pathogenesis, though differences between genders have not been evaluated. For this reason, we analysed features of mitochondrial oxidative metabolism, as well as mitochondrial chain complex enzyme activities and protein expression, lipid profile, and protein oxidative stress markers, in the Cu,Zn superoxide dismutase with the G93A mutation (hSOD1-G93A)- transgenic mice and Neuro2A(N2A) cells overexpressing hSOD1-G93A.Results and ConclusionsOur results show that overexpression of hSOD1-G93A in transgenic mice decreased efficiency of mitochondrial oxidative phosphorylation, located at complex I, revealing a temporal delay in females with respect to males associated with a parallel increase in selected markers of protein oxidative damage. Further, females exhibit a fatty acid profile with higher levels of docosahexaenoic acid at 30 days. Mechanistic studies showed that hSOD1-G93A overexpression in N2A cells reduced complex I function, a defect prevented by 17β-estradiol pretreatment. In conclusion, ALS-associated SOD1 mutation leads to delayed mitochondrial dysfunction in female mice in comparison with males, in part attributable to the higher oestrogen levels of the former. This study is important in the effort to further understanding of whether different degrees of spinal cord mitochondrial dysfunction could be disease modifiers in ALS.Electronic supplementary materialThe online version of this article (doi:10.1186/s40478-015-0271-6) contains supplementary material, which is available to authorized users.

Long-Term Effect of Docosahexaenoic Acid Feeding on Lipid Composition and Brain Fatty Acid-Binding Protein Expression in Rats.

Arachidonic (AA) and docosahexaenoic acid (DHA) brain accretion is essential for brain development. The impact of DHA-rich maternal diets on offspring brain fatty acid composition has previously been studied up to the weanling stage; however, there has been no follow-up at later stages. Here, we examine the impact of DHA-rich maternal and weaning diets on brain fatty acid composition at weaning and three weeks post-weaning. We report that DHA supplementation during lactation maintains high DHA levels in the brains of pups even when they are fed a DHA-deficient diet for three weeks after weaning. We show that boosting dietary DHA levels for three weeks after weaning compensates for a maternal DHA-deficient diet during lactation. Finally, our data indicate that brain fatty acid binding protein (FABP7), a marker of neural stem cells, is down-regulated in the brains of six-week pups with a high DHA:AA ratio. We propose that elevated levels of DHA in developing brain accelerate brain maturation relative to DHA-deficient brains.

Utilization of High-Fructose Corn Syrup for Biomass Production Containing High Levels of Docosahexaenoic Acid by a Newly Isolated Aurantiochytrium sp. YLH70

High-fructose corn syrup (HFCS) is an agro-source product and has been the most commonly used substitute for sugar as sweetener in food industry due to its low price and high solution property. In this study, the F55 HFCS, rich in fructose and glucose, was first tested for biomass and docosahexaenoic acid productions as a mixed carbon source by a newly isolated Aurantiochytrium sp.YLH70. After the compositions of the HFCS media were optimized, the results showed that the HFCS with additions of metal ion and vitamin at low concentrations was suitable for biomass and docosahexaenoic acid productions and the metal ion and sea salt had the most significant effects on biomass production. During the 5-l fed-batch fermentation, total HFCS containing 180 g l(-1) reducing sugar was consumed and yields of biomass, lipid, and DHA could reach 78.5, 51, and 20.1 g l(-1), respectively, at 114 h. Meanwhile, the daily productivity and the reducing sugar conversion yield for docosahexaenoic acid were up to 4.23 g l(-1)day(-1) and 0.11 g g(-1). The fatty acid profile of Aurantiochytrium sp.YLH70 showed that 46.4% of total fatty acid was docosahexaenoic acid, suggesting that Aurantiochytrium sp.YLH70 was a promising DHA producer.

Efficacy of docosahexaenoic acid-enriched formula to enhance maternal and fetal blood docosahexaenoic acid levels: Randomized double-blinded placebo-controlled trial of pregnant women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) compromises the level of docosahexaenoic acid (DHA) in phospholipids of maternal and fetal red blood cells and fetal plasma. This is of some concern because of the importance of DHA for fetal neuro-visual development. We have investigated whether this abnormality could be rectified by supplementation with DHA-enriched formula. Women with GDM (n=138) recruited from Newham University Hospital, London received two capsules of DHA-enriched formula (active-group) or high oleic acid sunflower seed oil (placebo-group) from diagnosis until delivery. Maternal (baseline and delivery) and fetal (cord blood) red blood cell and plasma phospholipid fatty acid composition, and neonatal anthropometry were assessed. One hundred and fourteen women (58 active, 56 placebo) completed the trial. The active-group compared with the placebo-group had significantly enhanced level of DHA in plasma phosphatidylcholine (4.5% vs 3.8%, P=0.011), red blood cell phosphatidylcholine (2.7% vs 2.2%, P=0.022) and phosphatidylethoanolamine (9.5% vs 7.6%, P=0.002). There was no difference in cord plasma and red blood cell phospholipid DHA between the two groups. The neonates of the two groups of women had comparable anthropometric measurements at birth. Daily supplementation of 600mg DHA enhances maternal but not fetal DHA status in pregnancy complicated by GDM. The inefficacy of the supplement to improve fetal status suggests that the transfer of DHA across the placenta maybe impaired in women with the condition. Regardless of the mechanisms responsible for the impairment of the transfer, the finding has implications for the management of neonates of women with GDM because they are born with a reduced level of DHA and the condition is thought to be associated with a risk of neuro-developmental deficits. We suggest that babies of women with GDM, particularly those not suckling, similar to the babies born prematurely require formula milk fortified with a higher level of DHA.