Amounts Of Docosahexaenoic Acid Research Articles

Use of Polyunsaturated Fatty Acids with α-Tocopherol in Poultry Feeds

The ability of α-tocopherol to prevent the degradation of the polyunsaturated fatty acids, docosahexaenoic acid (DHA) and linolenic acid (ALA) at elevated temperature was investigated in a series of laboratory experiments. DHA is known to promote nervous system function and health, however, DHA and other highly unsaturated fatty compounds are readily oxidized with loss of bioactivity. Mixtures of DHA or ALA and α-tocopherol were incubated at 70 °C. Samples of these mixtures were analyzed by gas chromatography. After 72 hours at 70 °C mixtures with 0.25 mg α-tocopherol/mg retained 79.6% of the initial amount of DHA and 94.2% of the ALA. When α-tocopherol was present at 2.5 mg/mg the amount of DHA decreased to 62.5% and ALA decreased to 87.4%. Control samples that did not contain α-tocopherol retained 43% DHA and 52.6% ALA. These results indicate that α-tocopherol can limit the degradation of these polyunsaturated fatty acids at elevated temperature. However, the greatest protective effect was not obtained with the highest level of α-tocopherol. This relationship needs to be considered when formulating feeds where elevated process temperatures are likely to occur.

Different Ratios of Docosahexaenoic and Eicosapentaenoic Acids Do Not Alter Growth, Nucleic Acid and Fatty Acids of Juvenile Cobia (Rachycentron canadum)

An experiment was performed to study the effect of different ratios of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on the growth, nucleic acid and fatty acids of cobia (Rachycentron canadum) juveniles. The juveniles were fed for 8 weeks using seven treatment diets (D-1-D-7) with the same amount of DHA and EPA (1.50 +/- 0.1% of dried diet), but varying ratios of DHA to EPA (0.90, 1.10, 1.30, 1.50, 1.70, 1.90, 2.10, respectively) and a control diet (D-0, DHA + EPA = 0.8% of dried diet, DHA/EPA = 1.30). At the end of the experiment, the mean body weight (BW) of juveniles fed D-0-D-7 increased significantly (from 6.86 +/- 1.64 in the week 0 to 58.52 +/- 16.45 g at the end of week 8, P < 0.05). The mean RNA amount and RNA/DNA ratio in the muscle (from 39.62 +/- 1.30 microg mg(-1) and 2.29 +/- 0.11 in the week 0 to 272.55 +/- 10.70 microg mg(-1) and 14.54 +/- 1.75 at the end of week 8, respectively) and the mean weight in the liver (from 117.70 +/- 11.15 microg mg(-1) and 3.14 +/- 0.25 in the week 0 to 793.07 +/- 13.38 microg mg(-1) and 13.16 +/- 0.76 at the end of week 8, respectively) of cobia juveniles fed D-0-D-7 were significantly higher at the end of 8-week experiment than initially (P < 0.05). The RNA/DNA ratio in the muscle and liver of cobia juveniles increased with their growth and appeared an obvious positive relationship, especially in the muscle, based on regression analysis. The mean lipid content increased significantly in the liver (from 29.82 +/- 0.99 to 37.47 +/- 3.25% totally) and muscle (from 6.74 +/- 0.25 to 10.63 +/- 0.23% totally) of cobia juveniles (P < 0.05). However, no significant difference was found on the lipid contents of juveniles fed different diets for 8 weeks (P > 0.05). In the muscle and liver of juveniles, EPA decreased with its reduction in the diet; DHA, DHA/EPA ratio and poly unsaturated fatty acids (PUFAs) generally increased with their increment in the diet. The conclusion was drawn that the growth, nucleic acid and fatty acids of cobia juveniles were not significantly affected by different DHA/EPA ratios in our experiments.

Fatty acids of neutral and phospholipids of three endangered trout: Salmo trutta caspius Kessler, Salmo trutta labrax Pallas and Salmo trutta macrostigma Dumeril

Total (TL), neutral (NL) and phospholipid (PL) amounts and fatty acid (FA) composition of female Salmo trutta caspius, Salmo trutta labrax and Salmo trutta macrostigma were investigated during one year. Twenty-three FAs were identified in both NLs and PLs. The principal FAs of both fractions were palmitic acid in saturated fatty acid, oleic acid in monounsaturated fatty acid, docosahexaenoic acid (DHA) in n-3 polyunsaturated fatty acids (n-3 PUFAs) and linoleic acid in n-6 PUFAs. The highest values for TLs, NLs and PLs were found in winter. As a general trend, the highest n-3/n-6 ratios and eicosapentaenoic acid (EPA) + DHA amounts were found in the winter and this coincided with the lowest gonado-somatic index.

Docosahexaenoic acid requirement for the prevention of abnormal morphology in brown sole Pseudopleuronectes herzensteini during D–E larval stages

We examined the docosahexaenoic acid (DHA) requirement during the sensitive period (D–E stages) to prevent abnormal morphology in juvenile brown sole Pseudopleuronectes herzensteini. Rotifers and Artemia nauplii containing three graded levels (low, mid, and high level) of DHA were made by respective enrichment with oil emulsion. Larvae at 15 days post hatching (dph) (D stage) were fed for 10 days with rotifers and Artemia nauplii containing respective amounts of DHA. During F–I stages, larvae were fed Artemia nauplii enriched with a commercial supplementary diet. The DHA requirement to prevent morphological abnormalities in brown sole juveniles was estimated to be 1.7–3.2% in rotifer and 1.4–2.8% in Artemia nauplii on a dry weight basis. Moreover it was clearly demonstrated that DHA enrichment of rotifers is superior to that of Artemia nauplii for this purpose in larval brown sole during D–E stages.

Synthesis and Characterization of a Structured Lipid from Amaranth Oil as a Partial Fat Substitute in Milk-Based Infant Formula

The aim of this study was to use enzymatic interesterification techniques to modify underutilized amaranth oil as a structured lipid (SL) by increasing its palmitic acid content at the sn-2 position and incorporating docosahexaenoic acid (DHA). This SL can be partially or complementarily used in milk-based infant formulas to deliver a lipid component similar to that in breast milk. Amaranth oil was modified by enzymatic interesterification in two stages. First, the palmitic acid content was increased specifically at the sn-2 position to resemble breast milk triacylglycerols (TAGs) using Novozym 435 lipase. Then DHA was incorporated, mainly at the sn-1,3 positions using Lipozyme RM IM, a sn-1,3 specific lipase. An optimization model was developed to determine the exact parameter combinations to incorporate a specific amount of DHA (1.0-2.5%). The model suggestions were used for a gram-scale interesterification to yield the expected product. The final SL composition was as follows: palmitic acid, 33.9%; stearic acid, 2.8%; oleic acid, 23.3%; linoleic acid, 37.3%; linolenic acid, 0.7%; and docosahexaenoic acid, 1.9%. The original amaranth oil and the final SL were characterized by determining the fatty acid composition, melting profile, chemical characteristics, oxidative stability (peroxide, p-anisidine, and total oxidation values), and phytosterol, tocopherol, and squalene contents. The physical and chemical characteristics determined in this study support the potential application of DHA-containing customized amaranth oil (DCAO) as a partial fat substitute or complement for milk-based infant formula. Research on the application and stability of this SL used in an infant formula is being conducted.

The effect of docosahexaenoic and eicosapentaenoic acids in live food on the development of abnormal morphology in hatchery-reared brown sole Pseudopleuronectes herzensteini

We examined the effect of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on the rates of abnormal morphology in juvenile brown sole Pseudopleuronectes herzensteini. Larvae during the D–E stages (15–24 days post hatching) were fed live food containing various amounts of DHA and/or EPA prepared using emulsified oils (DHA ethyl ester, EPA ethyl ester, and corn oil). Larvae during the F–I stages were fed Artemia enriched with a commercial diet supplement. We found that DHA and EPA promoted larval development and improved the incidence of morphological abnormalities in brown sole juveniles to a similar extent. However, DHA was more effective than EPA in preventing the appearance of morphological abnormalities in brown sole. The incidence of normal morphology was clearly improved by an increase of the DHA content in brown sole larvae at 25 days post-hatching. These results suggest that it is important to promote larval development and feed larvae with live food containing high levels of DHA during the D–E stages to prevent morphological abnormalities in brown sole juveniles.

Inhibition of astroglial glutamate transport by polyunsaturated fatty acids: Evidence for a signalling role of docosahexaenoic acid

Brain cells are especially rich in polyunsaturated fatty acids (PUFA), mainly the n-3 PUFA docosahexaenoic acid (DHA) and the n-6 PUFA arachidonic acid (AA). They are released from membranes by PLA2 during neurotransmission, and may regulate glutamate uptake by astroglia, involved in controlling glutamatergic transmission. AA has been shown to inhibit glutamate transport in several model systems, but the contribution of DHA is less clear and has not been evaluated in astrocytes. Because the high DHA content of brain membranes is essential for brain function, we investigated the role of DHA in the regulation of astroglial glutamate transport. We evaluated the actions of DHA and AA using cultured rat astrocytes and suspensions of rat brain membranes (P1 fractions). DHA reduced d-[ 3H]aspartate uptake by cultured astrocytes and cortical membrane suspensions, while AA did not. This also occurred in astrocytes enriched with α-tocopherol, indicating that it was not due to peroxidation products. The reduction of d-[ 3H]aspartate uptake by DHA did not involve any change in the concentrations of membrane-associated astroglial glutamate transporters (GLAST and GLT-1), suggesting that DHA reduced the activity of the transporters. In contrast with the inhibition induced by free-DHA, we found no effect of membrane-bound DHA on d-[ 3H]aspartate uptake. Indeed, the uptake was similar in astrocytes with varying amount of DHA in their membrane (induced by long-term supplementation with DHA or AA). Therefore, DHA reduces glutamate uptake through a signal-like effect but not through changes in the PUFA composition of the astrocyte membranes. Also, reactive astrocytes, induced by a medium supplement (G5), were insensitive to DHA. This suggests that DHA regulates synaptic glutamate under basal condition but does not impair glutamate scavenging under reactive conditions. These results indicate that DHA slows astroglial glutamate transport via a specific signal-like effect, and may thus be a physiological synaptic regulator.

Omega‐3 LC‐PUFA Supply and Neurological Outcomes in Children With Phenylketonuria (PKU)

Children with phenylketonuria (PKU) follow a diet with very low intakes of natural protein, which is devoid of food sources of the omega-3 docosahexaenoic acid (DHA). A resulting DHA depletion has been demonstrated in PKU children and may account for detectable subtle neurological deficits that are not explained by variation in plasma phenylalanine concentrations. We supplemented 36 children with PKU ages 1 to 11 years for 3 months with encapsulated fish oil providing a daily dose of 15 mg DHA/kg body weight. DHA supplementation resulted in significantly faster visual evoked potential latencies, indicating more rapid central nervous system information processing. In addition, DHA significantly improved outcomes in a test of motor function and coordination. No changes over time were seen in age-matched healthy controls. Because the PKU children had a good supply of the omega-3 precursor alpha-linolenic acid, these observations lead us to conclude that endogenous conversion of alpha-linolenic acid is not sufficient to provide adequate amounts of DHA that support optimal function, and hence DHA appears to be a conditional essential substrate for children with PKU. Because early treated PKU children are healthy, with normal fatty acid turnover, these data may indicate a need to supply some DHA to children in general. Further studies are ongoing aiming at establishing quantitative DHA requirements in children.

Lipid metabolism during embryonic development of the common snapping turtle, Chelydra serpentina

The metabolism of lipids and fatty acids during embryonic development of Chelydra serpentina (common snapping turtle) was investigated. Substantial changes in lipid class and fatty acid composition occurred as lipids were transferred from the yolk to the yolk sac membrane (YSM) and then to the brain, eyes, heart, and lungs of the hatchling. Lipids were hydrolyzed in the yolk prior to transport to the YSM, shown by a large increase in free fatty acids (FFAs) during the second half of development. Triglyceride-derived docosahexaenoic acid (DHA) was utilized preferentially to phospholipid-derived DHA. In the YSM, arachidonic acid (ARA) was selectively incorporated into phospholipids while DHA was preferentially incorporated into triglycerides. Selective incorporation of DHA and ARA into the brain and eyes, and ARA into the heart was observed, indicating the importance of these PUFAs for organ development and function. The amount of DHA and ARA in each organ was less than 1% of that measured in the yolk of the freshly laid egg, indicating that only a small portion of yolk PUFAs were incorporated into the hatchling organs studied. We discuss the differences in the mechanisms and utilization of yolk lipids in turtles compared with lipid uptake during embryonic development in birds.

Fatty acid facts, Part IV: Docosahexaenoic acid and Alzheimer's disease. A story of mice, men and fish

The primary pathological hallmark of Alzheimer's disease (AD) is neurodegeneration by neuronal cell death caused by the development of aggregates of beta- amyloid peptide. Epidemiologically, low fish intake and low blood levels of the omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) have been related to an increased risk of AD. Test animals on dietary DHA depletion show learning and memory deficits, whereas their brains show inflammatory and oxidative damage to neurons and synaptic defects. The behavioral defects could be reversed by DHA supplementation exemplified by improved cognitive function. Mechanistically, these phenomena have been explained by the antiinflammatory action of DHA. This immunomodulation has been ascribed to incorporation of increased amounts of DHA in cell membrane phospholipids, leading to decreased production of proinflammatory omega-6 eicosanoids. The latter molecules may cause vascular damage which promotes the clinical signs of AD. This review will provide an overview on the available knowledge with regard to the role of DHA in AD with a focus on mechanistic and epidemiological investigations.

IPD meta‐analysis shows no effect of LC‐PUFA supplementation on infant growth at 18 months

Clinical trials on the effects of long-chain polyunsaturated fatty acids (LC-PUFA) supplementation of formula milk on growth of term and preterm children have shown conflicting results. We examined the effects of LC-PUFAs-- especially docosahexaenoic acid (DHA) and arachidonic acid (AA)--on growth at 18 months. We performed a meta-analysis based on individual patient data (IPD) of 901 children from four large, randomised clinical trials of formula milk with and without LC-PUFAs. Anthropometrics were assessed by z-scores based on weight for age, length for age, head circumference for age and body mass index (BMI) for age at 18 months. The studies differed in LC-PUFA composition and infant characteristics (two studies on preterm children, two on term children). Multivariate regression analyses including the possible confounders, sex, gestational age, birth weight, smoking in the last trimester and maternal age, as well as interaction terms showed no significant effects of LC-PUFA supplementation on any z-score. Subgroup analyses on trials with high amounts of DHA and on studies with duration of supplementation of at least 6 months yielded the same result. These findings cannot be explained by the lack of power. Our IPD meta-analysis shows no evidence that LC-PUFA supplementation affects children's growth at 18 months of age.

No significant effect of additive ratios of docosahexaenoic acid to eicosapentaenoic acid on the survival and growth of cobia (Rachycentron canadum) juvenile

An experiment was conducted in the laboratory to investigate the effects of additive ratios of docosahexaenoic acid (DHA) to eicosapentaenoic acid (EPA) on the growth and survival of cobia (Rachycentron canadum) juveniles from August to October 2005. Three hundred and eighty cobia juveniles (56 days of age, body weight 6.9 ± 0.1 g, body length 9.2 ± 0.1 cm) were selected and 20 of them were freely taken for initial sample analysis in the week 0. Additional 360 juveniles were randomly assigned into eight groups with triplicate, total 24 tanks with 15 fish each. Cobia juveniles were reared in glass-steel tanks (200-L volume per tank) using filtered seawater with temperature 26–30.5 °C, salinity 25.4–33.0 g L−1 and pH 7.8–8.0. Cobia juveniles were fed for 8 weeks using seven treatment diets (D-1 to D-7) with the same amount of DHA and EPA (15.0 ± 1.2 g kg−1 of dried diet), but varying ratios of DHA to EPA (0.9, 1.1, 1.3, 1.5, 1.7, 1.9, 2.1, respectively) and a control diet (D-0, DHA + EPA = 8.0 g kg−1 of dried diet, DHA/EPA = 1.3). Five juveniles per tank were randomly taken for sample analysis at the end of weeks 4 and 8, respectively. The highest protein efficiency rate (PER; 1.5 in mean), average body weight (BW; 73.3 g per fish in mean) and the lowest feed conversion ratio (FCR; 1.6 in mean) were obtained in cobia juveniles fed the control diet at the end of week 8. These parameters were significantly different (P 0.05) was found among juveniles fed the treatment diets evaluated in this study. It was concluded that the survival and growth of cobia juveniles were not greatly influenced by additive ratios of DHA to EPA in our experimental conditions.

해양미세조류(Schizochytrium mangrovei MM103)를 이용한 발효 대두박 급이에 따른 DHA 다량 함유 육계와 계란의 생산

The objective of this study was to evaluate the docosahexaenoic acid (DHA) levels of meats and eggs from chickens which were fed fermented soybean meal (FSM) by marine microalgae (Schizochytrium mangrovei MM103). The diets contained different amounts of FSM at 0, 3, 5 and 10%. DHA content of carcass was increased with dietary FSM. DHA amounts in the breast meat were higher in the 10% FSM diet (2.21%) than the 5% (1.65%) and 3% (1.18%) FSM, and similar results were observed in the leg meat (10% FSM: 2.21%; 5% FSM: 1.65%; and 3% FSM: 1.18%, respectively) and in eggs (10% FSM: 2.02%; 5% FSM: 1.22%; and 3% FSM: 0.73%). The level of n-3 polyunsaturated fatty acids such as DHA (22:6n-3) in the FSM treatment was significantly higher than those of the other groups (p<0.05). The results demonstrated that FSM by marine microalgae could be used to enhance DHA amounts in chicken meats and eggs.

Crypthecodinium cohnii with emphasis on DHA production: a review

Docosahexaenoic acid (DHA) is a polyunsaturated fatty acid (PUFA) that belongs to the ω-3 group. In recent years, DHA has attracted much attention because of its recognized beneficial effect on human health. At present, fish oil is the major source of DHA, but it may be produced by microorganisms with additional benefits. Marine microorganisms may contain large amounts of DHA and are considered a potential source of this important fatty acid. Some of these organisms can be grown heterotrophically on organic substrates without light, offering the possibility of greatly increasing microalgal cell concentration under controlled and monitored conditions, resulting in a very high quality product. Among the heterotrophic marine dinoflagellates, Crypthecodinium cohnii has been identified as a prolific producer of DHA. The organism is extraordinary in that it produces no other PUFAs than DHA in its cell lipid in any significant amount, which makes the DHA purification process very attractive, particularly for pharmaceutical and nutraceutical applications. This paper reviews recent advances in the biotechnological production of DHA by C. cohnii.

The changes in the biochemical compositions and enzymatic activities of rotifer (Brachionus plicatilis, Müller) and Artemia during the enrichment and starvation periods

The changes in the biochemical compositions and enzymatic activities of rotifer (Brachionus plicatilis) and Artemia, enriched and stored at 4 degrees C temperature, were determined. The total starvation period was 16 h and samples were taken at the end of the 8th and 16th hours. In present study, the rotifer and nauplii catabolized a large proportion of the protein during the enrichment period. Lipid contents of both live preys increased during the enrichment period and decreased in nauplii and metanauplii throughout the starvation period but lipid content of the rotifer remained relatively constant during the starvation period. The changes observed in the amino acid compositions of Artemia and the rotifer were statistically significant (P < 0.05). The conspicuous decline the essential amino acid (EAA) and nonessential amino acid (NEAA) content of the rotifer was observed during the enrichment period. However, the essential amino acid (EAA) and nonessential amino acid (NEAA) contents of Artemia nauplii increased during the enrichment period. The unenriched and enriched rotifers contained more monounsaturated fatty acid (MUFAs) than polyunsaturated fatty acid (PUFAs) and saturated fatty acids (SFA). However, Artemia contained more PUFAs than MUFAs and SFA during the experimental period. A sharp increase in the amounts of docosahexaenoic acid (DHA) during the enrichment of the rotifer and Artemia nauplii was observed. However, the amount of DHA throughout the starvation period decreased in Artemia metanauplii but not in Artemia nauplii. Significant differences in tryptic, leucine aminopeptidase N (LAP), and alkaline phosphatase (AP) enzyme activities of Artemia and rotifer were observed during the enrichment and starvation period (P < 0.05). The digestive enzymes derived from live food to fish larvae provided the highest contribution at the end of the enrichment period. In conclusion, the results of the study provide important contributions to determine the most suitable live food offering time for marine fish larvae. Rotifer should be offered to fish larvae at the end of the enrichment period, Artemia nauplii just after hatching and before being stored at 4 degrees C, and Artemia metanauplii at the end of the enrichment and throughout the starvation period.

Dietary eicosapentaenoic acid and docosahexaenoic acid equally incorporate as decosahexaenoic acid but differ in inflammatory effects

Objective The ω-3 polyunsaturated fatty acids are involved in the modulation of the immune response. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) produced from dietary precursors may not be sufficient to match nutritional requirements and thus should be included in our diet. In this sense, the administration of higher amounts of DHA than of EPA in infant formulations is recommended. The aims of this work were to demonstrate that dietary administration of EPA or DHA to mice allows reaching similar tissue DHA levels and to compare their anti-inflammatory effects and mechanisms of action. Methods Balb/c mice were fed diets enriched with EPA or DHA for 3 wk. Twelve hours before sacrifice, a contact dermatitis was induced in the ears of the animals. Tissue fatty acid contents were determined. Cytokine and immunoglobulin concentrations were measured by enzyme-linked immunosorbent assay, and ears were collected to analyze local inflammatory effects. Results The DHA concentrations attained in tissues were similar to the two diets, whereas the EPA concentration increased only when the diet was enriched with this polyunsaturated fatty acid. Although EPA and DHA reduced ear inflammation, EPA reduced neutrophil infiltration in the ears more efficiently. EPA was associated with a greater reduction in the systemic macrophage inflammatory response and T-helper type 2 response and with increased interleukin-10 production. Conclusion Similar levels of DHA in tissues are reached in mice fed an EPA- or a DHA-enriched diet. Dietary EPA and DHA show anti-inflammatory properties, but EPA appears to be more potent.

Bioequivalence of Docosahexaenoic Acid from Different Algal Oils in Capsules and in a DHA‐Fortified Food

Docosahexaenoic acid (DHA), a long-chain omega-3 fatty acid, is important for eye and brain development and ongoing visual, cognitive, and cardiovascular health. Unlike fish-sourced oils, the bioavailability of DHA from vegetarian-sourced (algal) oils has not been formally assessed. We assessed bioequivalence of DHA oils in capsules from two different algal strains versus bioavailability from an algal-DHA-fortified food. Our 28-day randomized, placebo-controlled, parallel group study compared bioavailability of (a) two different algal DHA oils in capsules ("DHASCO-T" and "DHASCO-S") at doses of 200, 600, and 1,000 mg DHA per day (n = 12 per group) and of (b) an algal-DHA-fortified food (n = 12). Bioequivalence was based on changes in plasma phospholipid and erythrocyte DHA levels. Effects on arachidonic acid (ARA), docosapentaenoic acid-n-6 (DPAn-6), and eicosapentaenoic acid (EPA) were also determined. Both DHASCO-T and DHASCO-S capsules produced equivalent DHA levels in plasma phospholipids and erythrocytes. DHA response was dose-dependent and linear over the dose range, plasma phospholipid DHA increased by 1.17, 2.28 and 3.03 g per 100 g fatty acid at 200, 600, and 1,000 mg dose, respectively. Snack bars fortified with DHASCO-S oil also delivered equivalent amounts of DHA on a DHA dose basis. Adverse event monitoring revealed an excellent safety and tolerability profile. Two different algal oil capsule supplements and an algal oil-fortified food represent bioequivalent and safe sources of DHA.

N-3 poly-unsaturated fatty Acid (n-3PUFA) and neuroprotection: Is docosahexaenoic acid (DHA) involved in glutamate uptake by astrocytes?

The high amount of DHA (the main n-3PUFA) in brain cell membranes depends on n-3PUFA dietary intake. High n-3PUFA intakes reduce the occurrence of neurodegenerative diseases such as Alzheimer’s disease and have a protective effect on experimentally induced excitotoxicity. A high amount of DHA in cell membranes may thus confer to the brain a better resistance to insults. We recently showed that the amount of DHA in membrane phospholipids infl uences astrocytes physiology. Thus, the neuroprotective effect of n-3PUFA may rely on astrocyte functions involved in neuron protection and synaptic repair. Glutamate scavenging, a major task of astrocytes preventing excitotoxic damage, is under the infl uence of lipid signalling. We thus hypothesized that a high brain DHA content resulting from adequate n-3PUFA intakes may promote the glutamate uptake by astrocytes. We have explored the infl uence of membrane n-3PUFA status on glutamate uptake by astrocytes, on in vivo and in vitro models. In vivo, we compared the amount of astrocytic glutamate transporters GLAST and GLT-1 (western blot), in the cortex and hippocampus from n-3 supplemented or n-3 defi cient rats, from birth to 4 months old. In vitro, we compared GLAST and GLT-1 expression (western blot), 3H-aspartatve uptake and the capture of a bolus of glutamate, on astrocytes cultured in DHA-supplemented or control medium. In vivo and in vitro, n-3 PUFA supplementation induced a strong increase in the amount of DHA in membrane phospholipids (measured in phosphatidylethanolamine and phosphatidylcholine, by Gas Chromatography) as compared to n-3 deprived cells or rats. However, the DHA increase had no major consequences on glutamate transporters or uptake, in basal conditions. We are currently exploring the potential infl uence of DHA in conditions requiring enhanced glutamate c-apture and rapid addressing of the transporters to the membrane.

The Influence of Moderate and High Dietary Long Chain Polyunsaturated Fatty Acids (LCPUFA) on Baboon Neonate Tissue Fatty Acids

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are now common ingredients in commercial infant formulas, however, the optimal levels have not been established. Our previous data showed that the current amount of DHA in U.S. term formulas, 0.3%w/w, is insufficient to normalize cerebral cortex DHA to levels in breastfed baboon neonate controls (Diau et al.: BMC Medicine 3: 11, 2005). Here, we report on the influence of higher formula DHA levels on 12-wk-old full-term baboon CNS and visceral organs. Fourteen nursery-reared baboons were randomized to one of three diets: control (C, no DHA-ARA); moderate LCPUFA (L, 0.33%DHA-0.67%ARA); high LCPUFA (L3, 1.00%DHA-0.67%ARA). DHA increased significantly in liver, heart, and plasma (all C < L < L3), RBC (C < L, L3), and CNS regions: precentral gyrus (C < L < L3), frontal cortex, inferior and superior colliculi, globus pallidus, and caudate (all C < L, L3). These data extend previous observations indicating that 1) tissue DHA is more sensitive to diet than ARA; 2) cerebral cortex DHA increases with higher levels of DHA than in present commercial formulas; and 3) basal ganglia and limbic system DHA saturate with levels of DHA currently available in formulas. These results imply that higher levels of DHA are necessary to normalize cortex DHA to those found in breastfed animals.

Lipid Characterization of Mangrove Thraustochytrid − Schizochytrium mangrovei

Lipid class composition and distribution of fatty acids within the lipid pool of microalga, Schizochytrium mangrovei FB3 harvested at the late exponential phase, was studied, with special emphasis on the distribution of docosahexaenoic acid (C22:6 n-3, DHA). Neutral lipids were the major lipid constituents (95.90% of total lipids) in which triacylglyerol (TAG) was the predominant component and accounted for 97.20% of the neutral lipids. Phosphatidylcholine (PC) was the major polar lipid. Phosphatic acid and phosphatidylserine were the two classes in phospholipids reported for the first time in thraustochytrids. Both TAG and PC were primarily saturated and consisted of C16:0 at approximately 50% of total fatty acids. DHA was found to be distributed in all lipid classes and to be the major polyunsaturated fatty acid. TAG contained the highest amount of DHA, although the percentage of DHA in total fatty acids in TAG (29.74%) was lower than that in PC (39.61%). The result from this study would be useful for further optimization of DHA production by S. mangrovei.