Higher de novo synthesized fatty acids and lower ω3- and ω6-long-chain polyunsaturated fatty acids in umbilical vessels of women with preeclampsia and high fish intakes

Umbilical veins (UV) and arteries (UA) of preeclamptic women in Curaçao harbor lower long-chain polyunsaturated fatty acids (LCP). The present aim was to test these findings in Mwanza (Tanzania), whose inhabitants have high LCPω3 and LCPω6 intakes from Lake Victoria fish. Women with preeclampsia (n=28) in Mwanza had lower PUFA and higher 20:0 in UV and UA, compared with normotensive/non-proteinuric controls (n=31). Their UV 22:6ω3, 22:4ω6, LCPω6, ω6, and LCPω3+ω6 were lower, while saturated FA, potentially de novo synthesized FA (Σde novo) and (Σde novo)/(LCPω3+ω6) ratio were higher. Their UA had higher 16:1ω7, ω7, 18:0, and 16:1ω7/16:0. Umbilical vessels in Mwanza had higher 22:6ω3, LCPω3, ω3, and 16:0, and lower 22:5ω6, 20:2ω6, 18:1ω9, and ω9, compared to those in Curaçao. Preeclampsia in both Mwanza and Curaçao is characterized by lower LCP and higher Σde novo. An explanation of this might be placental dysfunction, while the similarity of umbilical vessel FA-abnormalities in preeclamptic and diabetic pregnancies suggests insulin resistance as a common denominator.     

The phospholipid fatty acids of Porphyridium purpureum cultured in the presence of triton x-100 and sodium desoxycholate

The phospholipid fatty acid composition of Porphyridium purpureum grown on a solid medium was studied in the presence of Triton X-100 (TX) and sodium desoxycholate (SDC). The most common fatty acids in PC and PE were palmitic (16:0), stearic (18:0), linoleic (18:2ω6), arachidonic (20:4ω6) and eicosapentaenoic (20:5ω3) acids, 20:4ω6 being very abundant. In PG the most common acids were 16:0, trans-hexaenoic acid (tr16:1ω3), oleic acid (18:1) and 20:4ω6. Both detergents caused an increase in the saturation of PC and, to a lesser extent, of PE. The relative amounts of short chain fatty acids increased. Both detergents increased the amounts of 16:0 and, correspondingly, decreased the amounts of 20:4ω6. In PG the amounts of both 16:0 and tr 16:1ω3 increased and the amounts of 18:0, 18:2ω6 and 20:4ω6 decreased in the presence of detergents. The changes were always greatest at the concentrations of 5–10 ppm TX or SDC. At 20 ppm the fatty acid compositions, especially with SDC, were very similar to the controls, which suggests a change in the detergent effect between 10–20 ppm. The normal PC/PE ratio was 5.6 and the (PC+ PE)/PG ratio 39.0. Both detergents caused a marked decrease in these ratios. Because the detergent effects are not linear, it seems that even very low detergent concentrations have an important influence on algae in polluted waters.     

Methyl-end desaturases with ∆12 and ω3 regioselectivities enable the de novo PUFA biosynthesis in the cephalopod Octopus vulgaris

The interest in understanding the capacity of aquatic invertebrates to biosynthesise omega-3 (ω3) long-chain (≥C₂₀) polyunsaturated fatty acids (LC-PUFA) has increased in recent years. Using the common octopus Octopus vulgaris as a model species, we previously characterised a ∆5 desaturase and two elongases (i.e. Elovl2/5 and Elovl4) involved in the biosynthesis of LC-PUFA in molluscs. The aim of this study was to characterise both molecularly and functionally, two methyl-end (or ωx) desaturases that have been long regarded to be absent in most animals. O. vulgaris possess two ωx desaturase genes encoding enzymes with ∆12 and ω3 regioselectivities enabling the de novo biosynthesis of the C₁₈ PUFA 18:2ω6 (LA, linoleic acid) and 18:3ω3 (ALA, α-linolenic acid), generally regarded as dietary essential for animals. The O. vulgaris ∆12 desaturase (“ωx2”) mediates the conversion of 18:1ω9 (oleic acid) into LA, and subsequently, the ω3 desaturase (“ωx1”) catalyses the ∆15 desaturation from LA to ALA. Additionally, the O. vulgaris ω3 desaturase has ∆17 capacity towards a variety of C₂₀ ω6 PUFA that are converted to their ω3 PUFA products. Particularly relevant was the affinity of the ω3 desaturase towards 20:4ω6 (ARA, arachidonic acid) to produce 20:5ω3 (EPA, eicosapentaenoic acid), as supported by yeast heterologous expression, and enzymatic activity exhibited in vivo when paralarvae were incubated in the presence of [1-¹⁴C]20:4ω6. These results confirmed that several routes enabling EPA biosynthesis are operative in O. vulgaris whereas ARA and docosahexaenoic acid (DHA, 22:6ω3) should be considered essential fatty acids since endogenous production appears to be limited.     

Long-chain polyenoics and the essential dietary fatty acid requirement of the waxmoth, Galleria mellonella

The essential fatty acid requirement for normal pupal-adult ecdysis in Galleria mellonella was studied using non-axenic casein-based semisynthetic diets with or without various 99% pure fatty acids. The abilities of linoleic and linolenic acids to alleviate faulty adult emergence differed markedly, linolenic acid being 10-fold more potent than linoleic acid. One other ω6 polyunsaturated fatty acid, C20:2ω6, resembled its analogue, linoleic acid (18:2ω6), in efficacy at high dosage, but three others, C18:3ω6, C20: ω6 and C20:4ω6 (arachidonic acid), were without effect. Of five ω3 polyunsatures tested, C22:3ω3 and C20:3ω3 were as effective as linolenic acid (C18:3ω3), their shorter-chained analogue. Docosahexaenoic acid (C22:6ω3) was totally ineffective, but eicosapentaenoic acid (C20:5ω3), though supporting no perfect emergences, produced some active adults having wing malformations only, and was therefore considered partially active. It is suggested that a C18 polyunsaturate is physiologically required by G. mellonella and can be derived from various dietary longer-chained analogues by simple carbon chain shortening so long as there are no additional double bonds carboxylwards of an active di- or trienoic sequence. The partial activity of C20:5ω3 suggests there may additionally be a physiological requirement for this or a related long-chain polyunsaturate. The possibility of multiple essential fatty acid requirements in Lepidoptera in general is discussed.     

Postdelivery changes in maternal and infant erythrocyte fatty acids in 3 populations differing in fresh water fish intakes

Introduction

Long-chain polyunsaturated (LCP) fatty acids (FA) are important during infant development. Mother-to-infant FA-transport occurs at the expense of the maternal status. Maternal and infant FA-status change rapidly after delivery.

Methods

Comparison of maternal (mRBC) and infant erythrocyte (iRBC)-FA-profiles at delivery and after 3 months exclusive breastfeeding in relation to freshwater-fish intakes. Approximation of de-novo-lipogenesis (DNL), stearoyl-CoA-desaturase (SCD), elongation-of-very-long-chain-FA-family-member-6 (Elovl-6), delta-5-desaturase (D5D) and delta-6-desaturase (D6D)-enzymatic activities from their product/essential-FA and product/substrate-ratios.

Results and discussion

Increasing iRBC-14:0 derived from mammary-gland DNL. Decreasing mRBC-ω9, but increasing iRBC-ω9, suggest high ω9-FA-transfer via breastmilk. Decreasing (m+i)RBC-16:0, DNL- and SCD-activities, but increasing (m+i)RBC-18:0 and Elovl-6-activity suggest more pronounced postpartum decreases in DNL- and SCD-activities, compared to Elovl-6-activity. Increasing (m+i)RBC-18:3ω3, 20:5ω3, 22:5ω3, 18:2ω6, mRBC-20:4ω6 and (m+i)D5D-activity, but decreasing mRBC-22:6ω3 and (m+i)D6D-activity and dose-dependent changes in iRBC-22:6ω3 confirm that D6D-activity is rate-limiting and 22:6ω3 is important during lactation. Fish-intake related magnitudes of postpartum FA-changes suggest that LCPω3 influence DNL-, SCD- and desaturase-activities.     

Reduced protein oxidation in Wistar rats supplemented with marine ω3 PUFAs

The potential effects of various dietary eicosapentaenoic acid (EPA; 20:5) and docosahexaenoic acid (DHA; 22:6) ratios (1:1, 2:1, and 1:2, respectively) on protein redox states from plasma, kidney, skeletal muscle, and liver were investigated in Wistar rats. Dietary fish oil groups were compared with animals fed soybean and linseed oils, vegetable oils enriched in ω6 linoleic acid (LA; 18:2) and ω3 α-linolenic acid (ALA; 18:3), respectively. Fish oil treatments were effective at reducing the level of total fatty acids in plasma and enriching the plasmatic free fatty acid fraction and erythrocyte membranes in EPA and DHA. A proteomic approach consisting of fluorescein 5-thiosemicarbazide (FTSC) labeling of protein carbonyls, FTSC intensity visualization on 1-DE or 2-DE gels, and protein identification by MS/MS was used for the protein oxidation assessment. Albumin was found to be the most carbonylated protein in plasma for all dietary groups, and its oxidation level was significantly modulated by dietary interventions. Supplementation with an equal EPA:DHA ratio (1:1) showed the lowest oxidation score for plasma albumin, followed in increasing order of carbonylation by 1:2 <2:1 ≈ linseed < soybean. Oxidation patterns of myofibrillar skeletal muscle proteins and cytosolic proteins from kidney and liver also indicated a protective effect on proteins for the fish oil treatments, the 1:1 ratio exhibiting the lowest protein oxidation scores. The effect of fish oil treatments at reducing carbonylation on specific proteins from plasma (albumin), skeletal muscle (actin), and liver (albumin, argininosuccinate synthetase, 3-α-hydroxysteroid dehydrogenase) was remarkable. This investigation highlights the efficiency of dietary fish oil at reducing in vivo oxidative damage of proteins compared to oils enriched in the 18-carbon polyunsaturated fatty acids ω3 ALA and ω6 LA, and such antioxidant activity may differ among different fish oil sources because of variations in EPA/DHA content.     

Fatty acid composition of the postmortem prefrontal cortex of adolescent male and female suicide victims

Prior epidemiological, prospective intervention, and peripheral and central fatty acid composition studies suggest that omega-3 fatty acid deficiency may be associated with the pathoaetiology of depression and suicide. In the present study, we determined the fatty acid composition of the postmortem prefrontal cortex (PFC) of adolescent male and female suicide victims and age-matched controls. Fatty acid composition (wt% total fatty acids) and concentrations (μmol/g) were determined in the postmortem PFC (Brodmann area 10) of male and female adolescent (aged 13–20 years) suicide victims (n=20) and age-matched controls (n=20) by gas chromatography. None of the major polyunsaturated fatty acids including the principle brain omega-3 fatty acid, docosahexaenoic acid (DHA), monounsaturated fatty acids, or saturated fatty acids differed significantly between adolescent suicide victims and controls before or after segregation by gender. The arachidonic acid (AA, 20:4n-6): DHA ratio and adrenic acid (22:4n-6) composition were negatively correlated with age at death in controls but not in suicides, and males exhibited a greater AA:DHA ratio irrespective of cause-of-death. These results demonstrate that adolescent male and female suicide victims do not exhibit DHA deficits in the postmortem PFC relative to age-matched controls, and suggest that suicide victims do not exhibit the normal age-related decrease in adrenic acid composition and the AA:DHA ratio.     

Age-related changes of n-3 and n-6 polyunsaturated fatty acids in the anterior cingulate cortex of individuals with major depressive disorder

Accumulating evidence finds a relative deficiency of peripheral membrane fatty acids in persons with affective disorders such as unipolar and bipolar depression. Here we sought to investigate whether postmortem brain fatty acids within the anterior cingulate cortex (BA-24) varied according to the presence of major depression at the time of death. Using capillary gas chromatography we measured fatty acids in a depressed group (n=12), and in a control group without lifetime history of psychiatric diagnosis (n=14). Compared to the control group, the depressed group showed significantly lower concentrations of numerous saturated and polyunsaturated fatty acids including both the n-3 and n-6 fatty acids. Additionally, significant correlations between age at death and precursor (or metabolites) in the n-3 fatty acid pathway were demonstrated in the depressed group but not in control subjects. In the n-6 fatty acid family, the ratio of 20:3(n-6)/18:2(n-6) was higher in patients than in control groups, whereas the ratio of 20:4(n-6)/20:3(n-6) was relatively decreased in patients. Lastly, a significant negative correlation between age and the ratio of 20:4(n-6) to 22:6(n-3) was found in patients, but not in controls. Taken together, decreases in 22:6(n-3) may be caused, at least in part, by the diminished formation of 20:5(n-3), which is derived from 20:4(n-3) through a Δ5 desaturase reaction. The present findings from postmortem brain tissue raise the possibility that an increased ratio of 20:4(n-6) to 22:6(n-3) may provide us with a biomarker for depression. Future research should further investigate these relationships.     

Delta-6 desaturase makes a different fatty acid profile of seed oil in Iranian borage (Echium amoenum Fisch. and Mey.)

Iranian borage (Echium amoenum) from Boraginaceae is a valuable medicinal plant native to Iran and Syria. We determined fatty acid profile and individual fatty acid contents in E. amoenum seed oil using gas chromatography. Nevertheless, the cumulative amount of ω-6 and ω-3 fatty acids in E. amoenum (78.5 %) was in great accordance with those of other species of Echium, Stearidonic acid (SDA, C18:4ω3) and gamma-linolenic acid (GLA, C18:3ω6) constituted only 9.7 % of seed oil in this plant. This observation elucidated the weak activity of delta-6 desaturase (D6DES) in E. amoenum compared with D6DESs of other species. As D6DES enzyme is responsible for converting linoleic acid (LA, C18:2ω6) and alpha-linolenic acid (ALA, C18:3ω3) to GLA and SDA, we isolated coding sequence of D6DES gene and characterized primary structure of the translated protein to probably find some evidences explaining the weak activity of D6DES enzyme in E. amoenum. Gene sequence from E. amoenum showed a high identity of 94–96 % with the other Echium species and the amino acid homology increased by 98 %. All the expected signatures including cytochrome b5 domain and three conserved histidine-rich motifs were found in the translated amino acid sequence. Protein alignment revealed that all the conserved motifs in D6DES sequence from E. amoenum are coincident with its counterparts from other Echium species. However, secondary structure of the enzyme deduced from its primary structure using computational simulation represented obvious differences with D6DES proteins of the other species.     

Influence de la température sur la composition en acides gras du muscle abdominal de Palaemon serratus

The shrimp Palaemon serratus was acclimatized at 9°, 15°, 18° and 25°, the lipid and fatty acids composition of the abdominal muscle show important variations. In relation to wet weight, total lipid level and polyunsaturated fatty acids (18:2ω6; 20:5ω3; 20:3ω6; 22:6ω3), show an inverse relationship with temperature. On the other hand, an increase of fatty acid content in relation to total lipids is observed as temperature increases. Some mono-unsaturated fatty acids have a polyunsaturated-like behaviour, others a saturated-like behaviour.     

Heterologous expression of Brassica juncea microsomal ω-3 desaturase gene (BjFad3) improves the nutritionally desirable ω-6:ω-3 fatty acid ratio in rice bran oil

Rice bran oil (RBO), being naturally rich in antioxidants, is currently regarded as one of the health-beneficial edible oils. However, the RBO has essential linoleic acid (ω-6, C18:2) and α-linolenic acid (ω-3, C18:3) in nutritionally disproportionate level (~25:1), contrary to the WHO/FAO’s recommendation of ~5:1. Among few naturally occurring C18:3 enriched oil-seeds, Brassica juncea (Indian mustard) has almost equal proportion of ω-6 and ω-3 fatty acids in its oil due to the activity of microsomal ω-3 desaturase (Fad3), which converts C18:2–C18:3. Therefore, the full length Fad3 coding DNA sequence (CDS) was isolated from the developing seeds of B. juncea, functionally characterized and heterologously expressed for the nutritional enhancement of RBO. Sequence analysis revealed that the 1,134 bp long BjFad3 CDS corresponds to a polypeptide of 377 amino acids, which is highly (85–95 %) homologous to other known Fad3 enzymes of plant kingdom. The BjFad3 gene was initially characterized in transgenic tobacco to establish its linoleate desaturase activity. Thereafter, rice bran-specific expression of the BjFad3 was carried out to alter the fatty acid profile of RBO. Several independent transgenic lines of tobacco and rice plants were developed by Agrobacterium-mediated transformation. Standard molecular biological techniques were used to confirm the transgene integration in the respective genomes and subsequent in planta expression. The BjFad3 transgene expression correlated to the significant increase in C18:3 fatty acid content (up to tenfold) in both tobacco seed oil and RBO, and thereby improving the nutritionally desirable ω-6:ω-3 ratio (~2:1) in one of the transgenic rice lines.     

Gestational age dependent changes of the fetal brain, liver and adipose tissue fatty acid compositions in a population with high fish intakes

IntroductionThere are no data on the intrauterine fatty acid (FA) compositions of brain, liver and adipose tissue of infants born to women with high fish intakes.Subjects and methodsWe analyzed the brain (n=18), liver (n=14) and adipose tissue (n=11) FA compositions of 20 stillborn infants with different gestational ages (range 8–38 weeks) born to Tanzanian women with low linoleic acid (LA) intakes and high intakes of docosahexaenoic (DHA) and arachidonic (AA) acids from local fish.Results and discussionWith advancing gestation, brain saturated-FA (SAFA; in g/100 g FA), polyunsaturated-FA (PUFA), DHA, 20:3ω6, 22:4ω6 and 22:5ω6 increased, while monounsaturated-FA (MUFA), 20:3ω9, 22:3ω9 and AA decreased. Decreasing brain AA might be caused by increasing AA-metabolism to 20:3ω6, 22:4ω6 and 22:5ω6. In the liver, SAFA, PUFA and LA increased, while MUFA decreased with gestation. The steep increase of (mostly de novo synthesized) SAFA in adipose tissue coincided with relative decreases of MUFA, PUFA, DHA, LA and AA with advancing gestation. Compared to Western infants, the currently studied African infants had higher DHA, lower AA, and a higher DHA/AA-ratio in brain and adipose tissue, while the LA content of adipose tissue was lower.ConclusionThe low LA and high DHA and AA intakes by the mothers of these infants might support optimal α-linolenic (ALA) vs. LA competition for Δ5D and Δ6D-activities and DHA vs. AA antagonism. Conversely, the Western diet, characterized by high LA and lower DHA and AA intakes, might disturb these evolutionary conserved mechanisms aiming at an optimal ω3/ω6-balance.     

Effect of frozen storage on fatty acid composition of the different tissues of four scombrid and one dussumeriid species

In the current study, the effect of frozen storage at ?18°C was evaluated on fatty acid composition of different body parts (liver, muscle tissue, and viscera) of narrow‐barred Spanish mackerel (Scomberomorus commerson, Lacépède, 1800), longtail tuna (Thunnus tonggol, Bleeker, 1851), kawakawa (Euthynnus affinis, Cantor, 1849), king mackerel (Scomberomorus guttatus, Bloch & Schneider, 1801), and rainbow sardine (Dussumieria acuta, Valenciennes, 1847) caught in the Persian Gulf. Changes in saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid plus docosahexaenoic acid/palmitic acid (EPA+DHA/C16), ω3 PUFA/ω6 PUFA (ω3/ω6), and polyunsaturated fatty acids/saturated fatty acids (PUFA/SFA) were investigated during a 6‐month period. A decrease in unsaturated fatty acids, particularly PUFAs (60–100%) as well as ω3/ω6, EPA+DHA/C16 (polyene index) and PUFA/SFA ratios, indicated a decrease in the nutritional values of the samples.     

INFLUENCE OF IRRADIANCE ON THE FATTY ACID COMPOSITION OF PHYTOPLANKTON1

Eight species of marine phytoplankton commonly used in aquaculture were grown under a range of photon flux densities (PEDs) and analyzed for their fatty acid (FA) composition. Fatty and composition changed considerably at different PFDs although no consistent correlation between the relative proportion of a single FA and μ or chl a · cell^?1 was apparent. Within an individual species the percentage of certain fatty acids covaried with PFDs, growth rate and/or chl a · cell^?1. The light conditions which produced the greatest proportion of the essential fatty acids was species specific. Eicosapentaenoic acid. 20:5ω3 increased from 6.1% to 15.5% of the total fatty acids of Chaetoceros simplex Ostenfield grown at PFDs which decreased from 225 μE · m^?2· s^?1 to 6 μE · m^?2· s^?1, respectively. Most species had their greatest proportion of 20: 5ω3 at low levels of irradiance. Conversely, docosahexaenoic acid, 22:6ω3, decreased from 9.7% to 3.6% of the total fatty acids in Pavlova lutheri Droop as PFD decreased. The percentage of 22:6ω3 generally decreased with decreasing irradiances. In all diatoms the percentage of 16:0 was significantly correlated with PFD, and in three of five diatoms, with growth rate (μ). Results suggest that fatty acid composition is a highly dynamic component of cellular physiology, which responds significantly to variation in PFD.     

The diet of the mud clam Geloina coaxans (Mollusca, Bivalvia) as indicated by fatty acid markers in a subtropical mangrove forest of Okinawa, Japan

Fatty acid compositions in the tissues of the clam Geloina coaxans collected from Oura mangal, Okinawa, Japan, during the cold and warm seasons (January and July 2001, respectively) were compared with those in suspended materials (SM) in order to assess the clams' diet. In both seasons, the suspended mangrove detritus at the sediment-water interface was high as indicated by the mean percentage of even-numbered long-chain fatty acids in SM (12.8-18.4%). The contribution of this marker in the clam tissues, especially during the cold season (3.9%), indicates the consumption of mangrove detritus in considerable amounts by the clams. The occurrence of the fatty acids 16:1ω7, 18:1ω9, 18:2ω6 and 18:3ω3 in SM was most likely due to the mangrove detritus sources, whereas in the SM they together constituted 12.9% and 23.9% of total fatty acid contents during the cold and warm seasons, respectively. As a result, their contribution in the clam tissues was high in the cold (15.4%) and warm seasons (19.0%). These results indicate that mangrove detritus play a significant role in the clams' diet. The mean percentages of bacterial markers (odd-numbered branched fatty acids and vaccenic acid, 18:1ω7) in the SM and tissues during both seasons ranged from 8.1% to 9.5%. This indicates that the clam diet is also dependent on the attached bacteria on the partially decomposed leaf detritus suspended at the sediment-water interface. The relative contribution by microalgae markers (18:4ω3, 20:5ω3 and 22:6ω3) in clam tissues ranged from 4.3% to 7.6%, suggesting considerable microalgae sources in the diets.     

Omega-3 fatty acid deficiency increases constitutive pro-inflammatory cytokine production in rats: Relationship with central serotonin turnover

Omega-3 (n-3) fatty acid deficiency, elevated inflammatory signaling, and central serotonin (5-HT) turnover have separately been implicated in the pathophysiology of major depressive disorder (MDD). In the present study we investigated the interrelationship between n-3 fatty acid status, pro-inflammatory signaling activity, and central 5-HT turnover in vivo. Rats were fed diets with or without the n-3 fatty acid precursor α-linolenic acid (ALA) during perinatal development (E0-P100), and a subset of rats fed the ALA− diet were switched to the ALA+ diet post-weaning (P21-P100, repletion). In adulthood (P100), plasma interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFα), and C-reactive protein (CRP) levels were measured. Additionally, indices of liver n-6 fatty acid biosynthesis, erythrocyte fatty acid composition, and regional brain monoamine turnover were determined. Indices of liver delta-6 desaturase activity were up-regulated in n-3-deficient rats, and were associated with greater erythrocyte membrane arachidonic acid (AA, 20:4 n-6) composition. Plasma IL-6 (p=0.001), TNFα (p=0.02), and CRP (p=0.001) concentrations were significantly greater in n-3-deficient rats relative to controls. The 5-HIAA/5-HT ratio was significantly greater in frontal cortex, hypothalamus, and ventral striatum of n-3-deficient rats relative to controls. Changes in membrane n-3 and n-6 fatty acid composition, elevations in plasma IL-6 and TNFα, and increased central 5-HT turnover were all prevented by normalization of n-3 fatty acid status. Erythrocyte docosahexaenoic acid (DHA, 22:6 n-3) was inversely correlated, and AA and the AA/DHA and AA/eicosapentaenoic acid ratios were positively correlated, with plasma IL-6, TNFα, and CRP levels. Plasma IL-6 levels were positively correlated with 5-HIAA/5-HT ratios in all brain regions. These preclinical data provide evidence for a functional link between n-3 fatty acid deficiency, elevated peripheral inflammatory signaling, and increased central 5-HT turnover.     

Sterols and fatty acids of the red tide flagellates Heterosigma akashiwo and Chattonella antiqua (Raphidophyceae)

The fatty acids and sterols of the raphidophyte flagellates, Heterosigma akashiwo (Australian and Plymouth strains) and Chattonella antiqua (Japanese strain) are reported. The major sterol of both species is 24-ethylcholesterol, which is more commonly associated with higher plants and has rarely been reported in unicellular algae. C. antiqua also contained 24-dihydrozymosterol [cholest-8(9)-en-3β-ol], which is also uncommon in marine algae. The major fatty acids in both raphidophytes are 16:0, 18:4ω3, 20:5ω3, 16:1ω7 and 14:0. Polyunsaturated fatty acids accounted for 46–50% of the total fatty acids in both species. The fatty acid 18:5ω3 was detected in H. akashiwo, but not in C. antiqua. This acid is found in some dinoflagellates and Prymnesiophycean algae, but this is the first report of its presence in the Raphidophyceae. The lipid distributions obtained for H. akashiwo and C. antiqua provide unique signature profiles for use in taxonomic, food-web and organic geochemical studies. The fatty acid and sterol distributions of these two raphidophytes justify their assignment to a separate class within the ‘brown algal’ line.     

Sub-Antarctic macroalgae: opportunities for gastronomic tourism and local fisheries in the Region of Magallanes and Chilean Antarctic Territory

In order to promote the use of sub-Antarctic macroalgae as food, four species of marine macroalgae: Macrocystis pyrifera, Durvillaea antarctica, Pyropia columbina, and Callophyllis variegata were studied for their nutritional value. They were collected monthly between October and December 2012 throughout the Strait of Magallanes, sub-Antarctic Chile. The chemical composition, including carbohydrates, proteins, lipids, and vitamins A and C, and the macronutrient, mineral, and fatty acid content were examined. Ash (15.1–34.1 %) and soluble fiber (26.5 to 40.3 %) were the most abundant in these species. Presence of protein was moderate (8.2–25.0 %), with red alga (C. variegata) having the highest value on dry weight (dw). All algal species had lipid contents of less than 5 % dw. Maximum carbohydrate content was observed in P. columbina (9.5 % dw). Potassium was the most abundant essential element found in M. pyrifera (8.51 % dw), while P. columbina was found to be richest in iron (305.5?±?5.5 μg g^?1 dw) and C. variegata showed the highest contents of Cu (17.4?±?0.7 μg g^?1 dw). The most abundant saturated fatty acids were palmitic (C16:0) and myristic acid (C14:0), with values ranging from 4.33 to 9.22 %. The most abundant monounsaturated fatty acid was oleic acid (C18:1ω9). The highest levels of polyunsaturated fatty acid were observed for arachidonic (20:4ω6) and eicosapentaenoic acid (C20:5ω3) or EPA.     

Lack of activation of UCP1 in isolated brown adipose tissue mitochondria by glucose-O-ω-modified saturated fatty acids of various chain lengths

We previously demonstrated that uncoupling protein 1 activity, as measured in isolated brown adipose tissue mitochondria (and as a native protein reconstituted into liposome membranes), was not activated by the non-flippable modified saturated fatty acid, glucose-O-ω-palmitate, whereas activity was stimulated by palmitate alone (40 nM free final concentration). In this study, we investigated whether fatty acid chain length had any bearing on the ability of glucose-O-ω-fatty acids to activate uncoupling protein 1. Glucose-O-ω-saturated fatty acids of various chain lengths were synthesized and tested for their potential to activate GDP-inhibited uncoupling protein 1-dependent oxygen consumption in brown adipose tissue mitochondria, and the results were compared with equivalent non-modified fatty acid controls. Here we demonstrate that laurate (12C), palmitate (16C) and stearate (18C) could activate GDP-inhibited uncoupling protein 1-dependent oxygen consumption in brown adipose tissue mitochondria, whereas there was no activation with glucose-O-ω-laurate (12C), glucose-O-ω-palmitate (16C), glucose-O-ω-stearate (18C), glucose-O-ω-arachidate (20C) or arachidate alone. We conclude that non-flippable fatty acids cannot activate uncoupling protein 1 irrespective of chain length. Our data further undermine the cofactor activation model of uncoupling protein 1 function but are compatible with the model that uncoupling protein 1 functions by flipping long-chain fatty acid anions.     

Fatty acid content of the dorsal muscle—an indicator of fat quality in freshwater fish

In 56 samples of freshwater fish, most were low in fat, ≤ 5% of dry weight (D.W.), and the sum of all fatty acids (ΣFA) was about 2% of D.W. Trout, whitefish, and grayling had the highest content of the long-chained FA. of ω3 type, EPA and DHA (1·7–2·6% of D.W.). Two large, low-fat pikes with ΣFA of about12–3% of D.W. and a medium-fat whitefish had the highest ω3/ω6 ratios, 8–9, whereas the fattiest fishes, eels from two lakes and the Baltic (ΣFA =17–26% of D.W.) had lower ω3/ω6 ratios, 1·1–1·8 (ω3 and ω6 FA are two important series of FA). The results indicate that ΣA controls the content of saturated FA (SAFA) and monounsaturated FA (MUFA), whereas the polyunsaturated FA (PUFA) was independent of ΣFA after a break point of about 10%ΣFA of D.W. The P/S ratio (PUFA/SAFA) and the PUFA/ΣFA ratio decreased with increased ΣFA, whereas the ω3/ω6 ratio showed no clear correlation to ΣFA. The difference in fatty acid patterns lay between low-fat and high-fat fishes, rather than between marine and freshwater fishes. The variation, both within and between species of the separate FA is small in fish with similar ΣFA content. Also, low-fat and medium-fat fishes tend to be more dietarily favourable than high-fat fishes, when considering the latest criteria for high nutritional value to humans. Abbreviations used in the text: FA, fatty acids; ΣFA, sum of all FA; AA, arachidonic acid (20 : 4ω6); EPA, eicosapentaenoic acid (20 : 5ω3); DHA, docosahexaenoic acid (22 : 6ω3); SAFA, saturated fatty acids; MUFA, monounsaturated fatty acids; PUFA, polyunsaturated fatty acids; D.W., dry weight; F.W. fresh weight; CV, coefficient of variation; ω3 FA, series of PUFA with the first double bond located at carbon number 3; ω6 FA, series of PUFA with the first double bond located at carbon number 6. The fatty acids are described by three numbers, x:ywz, where x=number of carbon atoms, y=number of double bonds, and z=position of the first double bond counted from the methyl end of the molecule.