bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly unsaturated fatty acid synthesis in vertebrates: New insights with the cloning and characterization of a Δ6 desaturase of Atlantic salmon
Authors: Zheng Xiaozhong , Tocher Douglas R. , Dickson Cathryn A. , Bell J. Gordon , Teale Alan J. 
Published: November 2006

AbstractFish are an important source of the n−3 highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids that are crucial to the health of higher vertebrates. The synthesis of HUFA involves enzyme‐mediated desaturation, and a Δ5 fatty acyl desaturase cDNA has been cloned from Atlantic salmon (Salmo salar) and functionally characterization of a Δ6 fatty acyl desaturase of Atlantic salmon and describe its genomic structure, tissue expression, and nutritional regulation. A salmon genomic library was screened with a salmon Δ5 desaturase cDNA and positive recombinant phage isolated and subcloned. The full‐length cDNA for the putative fatty acyl desaturase was shown to comprise 2106 bp containing an open reading frame of 1365 bp specifying a protein of 454 amino acids (GenBank accession no. AY458652). The protein sequence included three histidine boxes, two transmembrane regions, and an N‐terminal cytochrome b5 domain containing the heme‐binding motif HPGG, all of which are characteristic of microsomal fatty acid desaturases. Functional expression showed that this gene possessed predominantly Δ6 desaturase activity. Screening and sequence analysis of the genomic DNA of a single fish revealed that the Δ6 desaturase gene constituted 13 exons in 7965 bp of genomic DNA. Quantitative real‐time PCR assay of gene expression in Atlantic salmon showed that both Δ6 and Δ5 fatty acyl desaturase genes, and a fatty acyl elongase gene, were highly expressed in intestine, liver, and brain, and less so in kidney, heart, gill, adipose tissue, muscle, and spleen. Furthermore, expression of both Δ6 and Δ5 fatty acyl desaturase genes in intestine, liver, red muscle, and adipose tissue was higher in salmon fed a diet containing vegetable oil than in fish fed a diet containing fish oil.
β‐oxidation capacity of red and white muscle and liver in Atlantic salmon (Salmo salar L.)—Effects of increasing dietary rapeseed oil and olive oil to replace capelin oil
Authors: Stubhaug Ingunn , Frøyland Livar , Torstensen Bente E. 
Published: November 2006

AbstractPost‐smolt Atlantic salmon (Salmo salar) were fed six diets in which capelin oil was replaced with 0, 25, 50, 75, or 100% rapeseed oil (RO; low‐erucic acid) or 50% olive oil (OO). The experimental diets were fed to single groups of Atlantic salmon for 42 wk, whereas the 100% capelin oil (0% RO) diet was fed in duplicate. The β‐oxidation capacity of palmitoyl‐CoA was determined, using a method optimized for salmon tissues, at the start of the experiment, after 21 wk (October), and after 42 wk (March) in red and white muscle and in liver. Red muscle showed the highest specific β‐oxidation capacity, but when expressed as total β‐oxidation capacity for the whole tissue, white muscle was the most important tissue for the β‐oxidation of FA. From the initial to the final sampling, the β‐oxidation capacity of white muscle increased significantly, whereas the β‐oxidation capacity in liver decreased significantly. After 22 wk, white muscle exhibited an increased β‐oxidation capacity when the dietary RO content was raised from 25 to 75%, with similar effects in red muscle and liver after 42 wk of feeding. The present results also show that the β‐oxidation capacity increased with an increase in fish size.
Restoration of depressed prostanoid‐induced ileal contraction in spontaneously hypertensive rats by dietary fish oil
Authors: Patten Glen S. , Adams Michael J. , Dallimore Julie A. , Rogers Paul F. , Topping David L. , Abeywardena Mahinda Y. 
Published: November 2006

AbstractWe have reported that dietary fish oil (FO) rich in n−3 PUFA modulates gut contractility. It was further demonstrated that the gut of spontaneously hypertensive rats (SHR) has a depressed contractility response to prostaglandins (PG) compared with normotensive Wistar‐Kyoto (WKY) rats. We investigated whether feeding diets supplemented with n−3 PUFA increased gut contractility and restored the depressed prostanoid response in SHR gut. Thirteen‐week‐old SHR were fed diets containing fat at 5 g/100 g as coconut oil (CO), lard, canola oil containing 10% (w/w) n−3 FA as α‐linolenic acid (18∶3n−3), or FO (as HiDHA®, 22∶6n−3) for 12 wk. A control WKY group was fed 5 g/100 g CO in the diet. As confirmed, the SHR CO group had a significantly lower gut response to PGE2and PGF2αcompared with the WKY CO group. Feeding FO increased the maximal contraction response to acetylcholine in the ileum compared with all diets and in the colon compared with lard, and restored the depressed response to PGE2and PGF2αin the ileum but not the colon of SHR. FO feeding also led to a significant increase in gut total phospholipid n−3 PUFA as DHA (22∶6n−3) with lower n−6 PUFA as arachidonic acid (20∶4n−6). Canola feeding led to a small increase in ileal EPA (20∶5n−3) and DHA and in colonic DHA without affecting contractility. However, there was no change in ileal membrane muscarinic binding properties due to FO feeding. This report confirms that dietary FO increases muscarinic‐ and eicosanoid receptor‐induced contractility in ileum and that the depressed prostanoid response in SHR ileum, but not colon, is restored by tissue incorporation of DHA as the active nutrient.
Dietary n−3 polyunsaturated fatty acids increase T‐lymphocyte phospholipid mass and acyl‐CoA binding protein expression
Authors: Collison Lauren W. , Collison Robert E. , Murphy Eric J. , Jolly Christopher A. 
Published: November 2006

AbstractDietary flaxseed oil, which is enriched in α‐linolenic acid, and fish oil, which is enriched inEPA and DHA, possess anti‐inflammatory properties when compared with safflower oil, which is enriched in linoleic acid. The influence of flaxseed oil and fish oil feeding on lipid metabolism in T‐lymphocytes is currently unknown. This study directly compared the effects of feeding safflower oil, flaxseed oil, and fish oil for 8 wk on splenic T‐lymphocyte proliferation, phospholipid mass, and acyl‐CoA binding protein expression in the rat. The data show that both flaxseed oil and fish oil increased acyl‐CoA binding protein expression and phosphatidic acid mass in unstimulated T‐lymphocytes when compared with safflower oil feeding. Fish oil feeding increased cardiolipin mass, whereas flaxseed oil had no effect. After stimulation, flaxseed oil and fish oil blunted T‐lymphocyte interleukin‐2 production and subsequent proliferation, which was associated with the lack of incraased acyl‐CoA binding protein expression. The results reported show evidence for a novel mechanism by which dietary flaxseed oil and fish oil suppress T‐lymphocyte proliferation via changes in acyl‐CoA binding protein expression and phospholipid mass.
Milk fat synthesis is unaffected by abomasal infusion of the conjugated diene 18∶3 isomers cis‐6, trans‐10, cis‐12 and cis‐6, trans‐8, cis‐12
Authors: Sæbø A. , Perfield J. W. , Delmonte P. , Yurawecz M. P. , Lawrence P. , Brenna J. T. , Bauman D. E. 
Published: November 2006

AbstractIt has been previously established that trans‐10, cis‐12 CLA is a potent inhibitor of milk fat synthesis. Although the mechanism of this action is not completely understood, it has been speculated that eicosanoid‐like metabolites of this isomer formed by the activity of tissue desaturases may be responsible for its activity. The objective of this study was to investigate the effects of an enrichment containing an 18∶3 conjugated diene, produced in the metabolism of trans‐10, cis‐12 CLA, on milk fat synthesis. Three rumen‐fistulated Holstein cows (210±8 d in milk) were randomly assigned in a 3×3 Latin square experiment. Treatments were (i) control, (ii) trans‐10, cis‐12 CLA supplement (2.1 g/d; positive control), (iii) enrichment providing two conjugated diene 18∶3 isomers (2.6 g/d of cis‐6, trans‐10, cis‐12 and 4.0 g/d of cis‐6, trans‐8, cis‐12) and trans‐10, cis‐12 CLA (2.1 g/d). Treatments were abomasally infused for 5 d at 4‐h intervals, and there was a 7‐d interval between periods. Milk yield, dry matter intake, and milk protein yield were unaffected by treatments. In contrast, the trans‐10, cis‐12 CLA supplement reduced milk fat yield by 27%, whereas the supplement enriched with conjugated diene 18∶3 isomers (treatment iii) had no effect on milk fat yield beyond that attributable to its trans‐10, cis‐12 CLA content. The transfer efficiency of trans‐10, cis‐12 CLA into milk fat was 25 and 24% for treatments ii and iii, respectively. At the same time, the abomasally infused conjugated diene 18∶3 isomers were transferred to milk fat with an efficiency of 33 and 41% for cis‐6, trans‐10, cis‐12 and cis‐6, trans‐8, cis‐12 18∶3, respectively. Overall, short‐term abomasal infusion of the conjugated diene 18∶3 isomers had no effect on milk fat synthesis, thereby offering no support for an involvement of metabolies of trans‐10, cis‐12 CLA in the regulation of milk fat synthesis.
GC‐MS structural characterization of fatty acids from marine aerobic anoxygenic phototrophic bacteria
Authors: Rontani J. ‐F. , Christodoulou S. , Koblizek M. 
Published: November 2006

AbstractThe FA composition of 12 strains of marine aerobic anoxygenic phototrophic bacteria belonging to the genera Erythrobacter, Roseobacter, and Citromicrobium was investigated. GC‐MS analyses of different types of derivatives were performed to determine the structures of the main FA present in these organisms. All the analyzed strains contained the relatively rare 11‐methyloctadec‐12‐enoic acid, and three contained 12‐methyl‐octadec‐11‐enoic acid, which has apparently never been reported before. High amounts of the very unusual octadeca‐5,11‐dienoic acid were present in 9 of the 12 strains analyzed. A FA containing a furan ring was detected in three strains. Analytical data indicated that this FA was 10,13‐epoxy‐11‐methyloctadeca‐10,12‐dienoic acid. A very interesting enzymatic peroxidation of the allylic carbon 10 of cis‐vaccenic acid was observed in three strains. Deuterium labeling and GC‐MS analyses enabled us to demonstrate that this enzymatic process involves the initial dioxygenase‐mediated formation of 10‐hydroperoxyoctadec‐11(cis)‐enoic acid, which is then isomerized to 10‐hydroperoxyoctadec‐11(trans)‐enoic acid and converted to the corresponding hydroxy‐acids and oxoacids. Different biosynthetic pathways were proposed for these different compounds.
Preparation and fractionation of conjugated trienes from α‐linolenic acid and their growth‐inhibitory effects on human tumor cells and fibroblasts
Authors: Igarashi Miki , Miyazawa Teruo 
Published: November 2006

AbstractConjugated α‐linolenic acid (ClnA) was prepared from α‐linolenic acid (9,12,15–18∶3n−3, LnA) by alkaline treatment; we fractionated CLnA into three peaks by reversed‐phase column‐HPLC as evidenced by monitoring absorbance at 205, 235, and 268 nm. Peak I was a conjugated dienoic FA derived from LnA, whereas Peaks II and III were conjugated trienoic LnA. Proton NMR analysis showed that Peak III consisted of the all‐trans isomer. The methylated Peak III was further divided into five peaks (Peaks IV–VIII) by silver ion column‐HPLC. Peak V, a major constituent in the Peak III fraction, was identified as conjugated 10t,12t,14t‐LnA by GC‐EIMS and 1H NMR analysis. Peaks III and V, which consisted of conjugated all‐trans trienoic LnA, had stronger growth‐inhibitory effects on human tumor cell lines than the other collected peaks and strongly induced lipid peroxidation as compared with Peaks I, II, and LnA. We propose that conjugated all‐trans trienoic FA have the strongest growth‐inhibitory effect among the conjugated trienoic acids and conjugated dienoic acids produced by alkaline treatment of α‐LnA, and that this effect is mediated by lipid peroxidation.
Astonishing diversity of natural surfactants: 5. Biologically active glycosides of aromatic metabolites
Authors: Dembitsky Valery M. 
Published: November 2006

AbstractThis review article presents 342 aromatic glycosides, isolated from and identified in plants and microorganisms, that demonstrate different biological activities. They are of great interest, especially for the medicinal and/or pharmaceutical industries. These biologically active natural sufactants are good prospects for the future chemical preparation of compounds useful as antioxidant, anticancer, antimicrobial, and antibacterial agents. These glycosidic compounds have been classified into several groups, including simple aromatic compounds, stilbenes, phenylethanoids, phenylpropanoids, naphthalene derivatives, and anthracene derivatives.
Effects of the individual isomers cis‐9,trans‐11 vs. trans‐10,cis‐12 of conjugated linoleic acid (CLA) on inflammation parameters in moderately overweight subjects with LDL‐phenotype B
Authors: Ramakers Julian D. , Plat Jogchum , Sébédio Jean‐Louis , Mensink Ronald P. 
Published: November 2006

AbstractImmune‐modulating effects of CLA have been reported in animals, but results are inconsistent. In humans, CLA has shown no effects or only minor effects on immune function. The objective of this study was to evaluate the immune‐modulating effects of 3 g cis‐9,trans‐11 (c9,t11) vs. trans‐10,cis‐12 (t10,c12) CLA isomers in a population with a high risk of coronary heart disease characterized by moderate overweight (body‐mass index, 25–32.5 kg/m2) in combination with LDL‐phenotype B (≥35% small LDL cholesterol, density≥1.040 g/mL). After a run‐in period of 1 wk, 42 men and women were randomly allocated to the c9,t11 CLA group, the t10,c12 CLA group, or the placebo group. Effects of 13 wk of consumption of 3 g of CLA isomers on cytokine production by ex vivo lipopolysaccharide (LPS)‐stimulated peripheral blood mononuclear cells (PBMC) and whole blood, and on plasma C‐remononuclear protein (CRP) concentrations were evaluated. To generate hypotheses for future studies, protein expression patterns of 42 cytokines, chemokines, and growth factors were evaluated with an antibody array in pooled, nonstimulated, fasting plasma samples. LPS induced interleukin (IL)‐6, IL‐8, and tumor necrosis factor‐α production by PBMC, and whole blood as well as plasma CRP concentrations were not significantly changed by the c9,t11, and the t10,c12 CLA isomers. The cytokine expression profile in nonstimulated plasma suggested that both CLA isomers induced a specific inflammatory signature, in which the c9,t11 CLA group showed more activity in terms of numbers of proteins regulated. We conclude that daily consumption of 3 g of c9,t11 or t10,c12 CLA isomer did not affect LPS‐stimulated cytokine production by PBMC or whole blood and plasma CRP levels. Inflammatory signatures in fasting, nonstimulated plasma as determined by an antibody array may indicate enhanced immune function by both CLA isomers.
Dietary sitostanol and campestanol: Accumulation in the blood of humans with sitosterolemia and xanthomatosis and in rat tissues
Authors: Connor William E. , Lin Don S. , Pappu Anuradha S. , Frohlich Jiri , Gerhard Glenn 
Published: November 2006

AbstractDietary sitostanol has a hypocholesterolemic effect because it decreases the absorption of cholesterol. However, its effects on the sitostanol concentrations in the blood and tissues are relatively unknown, especially in patients with sitosterolemia and xanthomatosis. These patients hyperabsorb all sterols and fail to excrete ingested sitosterol and other plant sterols as normal people do. The goal of the present study was to examine the absorbability of dietary sitostanol in humans and animals and its potential long‐term effect. Two patients with sitosterolemia were fed the margarine Benecol (McNeill Nutritionals, Ft. Washington, PA), which is enriched in sitostanol and campestanol, for 7–18 wk. Their plasma cholesterol levels decreased from 180 to 167 mg/dL and 153 to 113 mg/dL, respectively. Campesterol and sitosterol also decreased. However, their plasma sitostanol levels increased from 1.6 to 10.1 mg/dL and from 2.8 to 7.9 mg/dL, respectively. Plasma campestanol also increased. After Benecol withdrawal, the decline in plasma of both sitostanol and campestanol was very sluggish. In an animal study, two groups of rats were fed high‐cholesterol diets with and without sitostanol for 4 wk. As expected, plasma and liver cholesterol levels decreased 18 and 53%, respectively. The sitostanol in plasma increased fourfold, and sitostanol increased threefold in skeletal muscle and twofold in heart muscle. Campestanol also increased significantly in both plasma and tissues. Our data indicate that dietary sitostanol and campestanol are absorbed by patients with sitosterolemia and xanthomatosis and also by rats. The absorbed plant stanols were deposited in rat tissues. Once absorbed by sitosterolemic patients, the prolonged retention of sitostanol and campestanol in plasma might increase their atherogenic potential.
Monitoring the oxidation of docosahexaenoic acid in lipids
Authors: Lyberg Ann‐Marie , Fasoli Ezio , Adlercreutz Patrick 
Published: November 2006

AbstractThe oxidation of free DHA, DHA mixed with PC, and DHA incorporated into PC, PE, or TG was evaluated to determine which lipid provided DHA with the best protection against oxidation. DHA was either situated at the sn‐1 position, sn‐2 position, or both positions of the phospholipid, whereas the TG contained DHA at all positions. All lipids were incubated as bulk lipids, in chloroform, or as an emulsion in contact with air at 25–30°C for 28 d. Since DHA, which is highly sensitive to oxidation, has a great impact on our health and is desired as a food additive, the stability of this FA is of great importance. This study was mainly focused on the primary oxidation products, which were monitored as eight monohydroperoxy‐DHA isomer groups, the total amount of polyhydroperoxides, and the PV. However, a measure of secondary oxidation products, the carbonyl value, was also monitored. We found that DHA was most protected against hydroperoxide formation when it was incorporated at one position of either PC or PE. In these lipids, hydroperoxide formation at carbon atoms 4, 7, 8, and 11 was completely prevented. DHA mixed with PC was also protected, although to a lesser extent, and all hydroperoxide isomers were detected. In contrast, PC and TG containing DHA at all positions should be avoided, since they were highly oxidized.
Influence of diet on the kinetic behavior of hepatic carnitine palmitoyltransferase I toward different acyl CoA esters
Authors: Power Glen W. , Cake Max H. , Newsholme Eric A. 
Published: November 2006

AbstractThe influence of diet on the kinetics of the overt form of rat liver mitochondrial carnitine palmitoyltransferase (CPT I; EC 2.3.1.21) was studied using rats fed either a low‐fat diet (3% w/w fat), or diets which were supplemented with either olive oil (OO), safflower oil (SO) or menhaden (fish) oil (MO) to 20% w/w of fat (high fat diets). When animals were fed each of these four diets for 10 days, the order of the apparent maximal activity (Vmax) of CPT I toward various individual fatty acyl CoA, when measured under a fixed molar ratio of acyl CoA/albumin, was 16∶1n−7>18∶1n−9>18∶2n−6>16∶0>22∶6n−3, and was thus not affected by the fat composition of the diet. However, in all but one case, the SO and MO diets elicited a higher Vmax for each substrate than either the LF diet or the high fat OO diet. The apparent K0.5 for the different acyl CoA esters was generally lowest in LF‐fed animals, and highest in those fed the high‐fat SO diet. Moreover, when compared with the situation of animals fed high‐fat diets, the K0.5 values of CPT I in LF‐fed animals for palmitoyl CoA and oleoyl CoA were low. This possession by CPT I of a high “affinity” toward these nonessential fatty acyl CoAs, but a lower “affinity” toward linoleoyl CoA, the ester of an essential fatty acid, may enable this latter fatty acid to be spared from oxidation when its concentration in the diet is low. The data also emphasize that palmitoleoyl CoA, if available in the diet, is likely to be utilized by CPT I at a high rate.
Lipid composition of cultured endothelial cells in relation to their growth
Authors: Cansell Maud , Gouygou Jean‐Paul , Jozefonvicz Jacqueline , Letourneur Didier 
Published: November 2006

AbstractHuman endothelial cells in culture were examined in different growth conditions. The human endothelial cell line, EA.hy 926 cell line, was used and cells were studied either in exponential growth phase, at confluence, or growth‐arrested by serum deprivation. Phospholipids were separated and analyzed by high‐performance thin‐layer chromatography, and their fatty acids were quantified by gas‐liquid chromatography. No significant differences in the phospholipid distributions were found between exponentially growing and confluent endothelial cells in which phosphatidylcholine (PC) represented the major phospholipid. In comparison, serum‐deprived cells exhibited higher proportions of sphingomyelin and lower content of PC. We also found that among the total lipids, cholesterol level for dividing endothelial cells was lower than for cells growth‐arrested either by serum deprivation or by contact inhibition at confluence. The global fatty acid distribution was not affected by the growth conditions. Thus, oleate (18∶1n−9 and 18∶1n‐7), palmitate (C16∶0), and stearate (C18∶0) were the main components of endothelial cell membranes. However, the fatty acid distributions obtained from each phospholipid species differed with the growth status. Altogether, the data indicated that subtle modulations of endothelial cell metabolism appear upon cell growth. The resulting membrane‐dependent cellular functions such as cholesterol transport and receptor activities can be expected to be relevant for lipid trafficking within the vessel wall in vitro and in vivo.
Effect of radiotherapy and chemotherapy on composition of tumor membrane phospholipids
Authors: Street James C. , Koutcher Jason A. 
Published: November 2006

AbstractPhospholipid extracts were made of a murine mammary adenocarcinoma implanted in the dorsum of the foot of C3H/He mice before and 96 h after 17 Gy irradiation or 150 mg/kg cyclophosphamide. Extracts of untreated tumors, which had grown for a further 96 h, were also studied. Although previous studies have shown significant changes in the precursors and catabolites of phosphatidylcholine and phosphatidylethanolamine following therapy, 31P nuclear magnetic resonance analysis of extracts showed no changes in these membrane constituents and other observed phospholipid species. A significant decrease in 1‐alkyl‐2‐acyl‐sn‐glycero‐3‐phosphocholine, however, was observed 96 h following cyclophosphamide treatment.
Dietary very long chain fatty acids directly influence the ratio of tetracosenoic (24∶1) to tetracosanoic (24∶0) acids of sphingomyelin in rat liver
Authors: Bettger W. J. , Blackadar C. B. 
Published: November 2006

AbstractTwenty‐one groups of weanling male Wistar rats were fed semipurified diets containing 5% (w/w) of different dietary fats. After 2 wk, liver sphingomyelin (SM) fatty acid composition was determined. The ratio of 24∶1 to 24∶0 in liver SM varied over a tenfold range in response to dietary fat type. Stepwise multiple regression analysis indicated that dietary 24∶1, 24∶0, and 22∶1 were the most significant factors in predicting the 24∶1/24∶0 ratio of liver SM. The mathematical relation between the dietary fatty acid composition and liver SM 24∶1/24∶0 was y=1.88 (24∶1)−1.49 (24∶0)+0.21 (22∶1)+0.01 (18∶1)+0.26, r2=0.95, P<0.0001. These results were confirmed by a second experiment in which the rats were fed olive oil‐based diets supplemented with various fatty acid ethyl esters.