bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidation rate of conjugated linoleic acid and conjugated linolenic acid is slowed by triacylglycerol esterification and α‐tocopherol
Authors: Tsuzuki Tsuyoshi , Igarashi Miki , Iwata Toshio , Yamauchi‐Sato Yoshie , Yamamoto Takaya , Ogita Kanehide , Suzuki Toshihide , Miyazawa Teruo
Published: November 2006

We have recently shown that α‐eleostearic acid (α‐ESA), a conjugated linolenic acid, has a stronger antitumor effect than conjugated linoleic acid (CLA), both in vitro and in vivo. In this study, the oxidative stability of α‐ESA was examined compared with linoleic acid (LA), α‐linolenic acid (LnA), and CLA. Thin layers of the FA (LA, 9Z, 11E‐CLA, 10E,12Z‐CLA, LnA, and α‐ESA) were auto‐oxidized at 37°C, and the FA remaining, the absorbed oxygen volume, the lipid hydroperoxide content, and the TBARS content were determined. The oxidation rate of α‐ESA was faster than that of the unconjugated FA and CLA (9Z,11E‐CLA and 10E,12Z‐CLA). However, the lipid hydroperoxide and TBARS contents following α‐ESA oxidation were low, suggesting production of only small amounts of rapid‐reacting secondary oxidation products. Furthermore, the oxidative stability of conjugated FA (CLA and CLnA) in which the carboxylic acid group was esterified with triacylglycerol was greater than that of the FFA. Addition of an antioxidant (α‐tocopherol) also increased the stability of the conjugated FA to a level similar to that of the unconjugated FA.
Effects of hydrocarbon structure on fatty acid, fatty alcohol, and β‐hydroxy acid composition in the hydrocarbon‐degrading bacterium Marinobacter hydrocarbonoclasticus
Authors: Soltani Mohamed , Metzger Pierre , Largeau Claude
Published: November 2006

The lipids of the gram‐negative bacterium Marinobacter hydrocarbonoclasticus grown in a synthetic seawater medium supplemented with various hydrocarbons as the sole carbon source were isolated, purified, and their structures determined. The hydrocarbons were normal, iso, anteiso, and mid‐chain branched alkanes, phenylalkanes, cyclohexylalkanes, and a terminal olefin. According to the sequential procedure used for lipid extraction, three pools were isolated: unbound lipids extracted with organic solvents (corresponding to metabolic lipids and to the main part of membrane lipids), OH− labile lipids [mainly ester‐bound in the lipopolysaccharides (LPS)], and H+ labile lipids (mainly amide‐bound in the LPS). Each pool contained FA, fatty alcohols, and β‐hydroxy acids. The proportions of these lipids in the unbound lipid pools were 84–98%, 1.1–11.6%, and 0.1–3.6% (w/w), respectively. The chemical structures of the lipids were strongly correlated with those of the hydrocarbons fed; analytical data suggested a metabolism essentially through oxidation into primary alcohol, then into FA and degradation via the β‐oxidation pathway. Subterminal oxidation of the hydrocarbon chains, α‐oxidation of FA or double‐bond oxidation in the case of the terminal olefin, were minor, although sometimes substantial, routes of hydrocarbon degradation. Cyclohexyldodecanedid not support growth, likely because of the toxicity of cyclohexylacetic acid formed in the oxidation of the alkyl side chain. In the OH− and H+ labile lipid pools, β‐hydroxy acids, the lipophilic moiety of LPS, generally dominated (28–72% and 64–98%, w/w, respectively). The most remarkable feature of these cultures on hydrocarbons was the incorporation in LPS of β‐hydroxy acids with Codd, ω‐unsaturated, iso, or anteiso alkyl chains in addition to the specific β‐hydroxy acid of M. hydrocarbonoclasticus, 3‐OH‐n‐12∶0. These β‐hydroxy acids were tolerated insofar as their geometry and steric hindrance were close to those of the 3‐OH‐n‐12∶0 acid.
Dietary intakes and food sources of n−6 and n−3 PUFA in french adult men and women
Authors: Astorg Pierre , Arnault Nathalie , Czernichow Sébastien , Noisette Nathalie , Galan Pilar , Hercberg Serge
Published: November 2006

The intake of individual n−6 and n−3 PUFA has been estimated in 4,884 adult subjects (2,099 men and 2,785 women), volunteers from the French SU.VI.MAX intervention trial. The food intakes of each subject were recorded in at least ten 24‐h record questionnaires completed over a period of 2.5 yr, allowing the estimation of the daily intake of energy; total fat; and linoleic, α‐linolenic, arachidonic, eicosapentaenoic (EPA), n−3 docosapentaenoic (DPA), and docosahexaenoic (DHA) acids. The mean total fat intake corresponded to 94.1 g/d (36.3% of total energy intake) in men and 73.4 g/d (38.1% of energy) in women. The intake of linoleic acid was 10.6 g/d in men and 8.1 g/d in women, representing 4.2% of energy intake; that of α‐linolenic acid was 0.94 g/d in men and 0.74 g/d in women, representing 0.37% of energy intake, with a mean linoleic/α‐linolenic acid ratio of 11.3. The mean intakes of long‐chain PUFA were: arachidonic acid, 204 mg/d in men and 152 mg/d in women; EPA, 150 mg/d in men and 118 mg/d in women; DPA, 75 mg/d in men and 56 mg/d in women; DHA, 273 mg/d in men and 226 mg/d in women; long‐chain n−3 PUFA, 497 mg/d in men and 400 mg/d in women. Ninety‐five percent of the sample consumed less than 0.5% of energy as α‐linolenic acid, which is well below the current French recommendation for adults (0.8% of energy). In contrast, the mean intakes of long‐chain n−6 and n−3 PUFA appear fairly high and fit the current French recommendations (total long‐chain PUFA: 500 mg/d in men and 400 mg/d in women; DHA: 120 mg/d in men and 100 mg/d in women). The intakes of α‐linolenic acid, and to a lesser extent of linoleic acid, were highly correlated with that of lipids. Whereas the main source of linoleic acid was vegetable oils, all food types contributed to α‐linolenic acid intake, the main ones being animal products (meat, poultry, and dairy products). The main source of EPA and DHA (and of total long‐chain n−3 PUFA) was fish and seafood, but the major source of DPA was meat, poultry, and eggs. Fish and seafood consumption showed very large interindividual variations, the low consumers being at risk of insufficient n−3 PUFA intake.
Incorporation of n−3 fatty acids into plasma and liver lipids of rats: Importance of background dietary fat
Authors: MacDonald‐Wicks Lesley K. , Garg Manohar L.
Published: November 2006

The health benefits of long‐chain n−3 PUFA (20∶5n−3 and 22∶6n−3) depend on the extent of incorporation of these FA into plasma and tissue lipids. This study aimed to investigate the effect of the background dietary fat (saturated, monounsaturated, or n−6 polyunsaturated) on the quantitative incorporation of dietary 18∶3n−3 and its elongated and desaturated products into the plasma and the liver lipids of rats. Female weanling Wistar rats (n=54) were randomly assigned to six diet groups (n=9). The fat added to the semipurified diets was tallow (SFA), tallow plus linseed oil (SFA‐LNA), sunola oil (MUFA), sunola oil plus linseed oil (MUFA‐LNA), sunflower oil (PUFA), or sunflower oil plus linseed oil (PUFA‐LNA). At the completion of the 4‐wk feeding period, quantitative FA analysis of the liver and plasma was undertaken by GC. The inclusion of linseed oil in the rat diets increased the level of 18∶3n−3, 20∶5n−3, and, to a smaller degree, 22∶6n−3 in plasma and liver lipids regardless of the background dietary fat. The extent of incorporation of 18∶3n−3, 20∶5n−3, and 22∶5n−3 followed the order SFA‐LNA>MUFA‐LNA>PUFA‐LNA. Levels of 22∶6n−3 were increased to a similar extent regardless of the type of major fat in the rat diets. This indicates that the background diet affects the incorporation in liver and plasma FA pools of the n−3 PUFA with the exception of 22∶6n−3 and therefore the background diet has the potential to influence the already established health benefits of long‐chain n−3 fatty acids.
Photochemical production of conjugated linoleic acid from soybean oil
Authors: Gangidi R. R. , Proctor A.
Published: November 2006

Conjugated linoleic acid (CLA), an anticarcinogenic compound with numerous other health benefits, is present mainly in dairy and beef lipids. The main CLA isomer present in dairy and beef lipids iscis9,trans11 CLA at a 0.5% concentration. The typical minimum human dietary intake of CLA is 10 times less than the 3 g/d suggested requirement that has been extrapolated from animal and cell‐line studies. The objectives of this study were to produce CLA isomers from soybean oil by photoisomerization of soybean oil linoleic acid and to study the oxidation status of the oil. Refined, bleached, and deodorized soybean oil with added iodine concentrations of 0, 0.1, 0.25, and 0.5% was exposed to a 100‐W mercury lamp for 0 to 120 h. An SP‐2560 fused‐silica capillary GC column with FID was used to analyze the esterified CLA isomers in the photoisomerized oil. The CLA content of the individual isomers was optimized by response surface methodology. Attenuated total reflectance (ATR)‐FTIR spectra in the 3400 to 3600 cm−1range and1H NMR spectra in the 8 to 12 ppm range of the photoisomerized soybean oil were obtained to follow hydroperoxide formation. The largest amount ofcis9,trans11 CLA isomer in soybean oil was 0.6%, obtained with 0.25% iodine and 84 h of photoisomerization. Lipid hydroperoxide peaks in the ATR‐FTIR spectra and aldehyde peaks in the1H NMR spectra were not observed in the photoisomerized soybean oil, and the spectra were similar to that of fresh soybean oil. This study shows that CLA isomers can be produced simply and inexpensively from soybean oil by photoisomerization.
Cigarette smoke negatively and dose‐dependently affects the biosynthetic pathway of the n−3 polyunsaturated fatty acid series in human mammary epithelial cells
Authors: Marangoni Franca , Colombo Claudio , De Angelis Leonardo , Gambaro Veniero , Agostoni Carlo , Giovannini Marcello , Galli Claudio
Published: November 2006

Maternal smoking during pregnancy has been associated with a reduced content of n−3 long‐chain PUFA (LC‐PUFA) in breast milk, thereby reducing the intake of key nutrients by the infants. We postulated that the mammary gland is affected by maternal smoking in the process of n−3 LC‐PUFA secretion into milk. This prompted us to investigate the effects of cigarette smoke on the synthesis of n−3 LC‐PUFA in vitro by using a line of healthy epithelial cells from the human mammary gland, MCF‐10A. Cells were exposed to cigarette smoke under controlled conditions by adding to the medium aliquots of horse serum containing smoke components, as analyzed by GC‐MS. The major findings concern the inhibition of both the conversion of the precursor 14C‐ALA (α‐linolenic acid) to n−3 LC‐PUFA and of the Δ5 desaturation step (assessed by HPLC analysis with radiodetection of n−3 FAME) following exposure to minimal doses of smoke‐enriched serum, and the dose‐dependent relationship of these effects. The data indicate that exposure to cigarette smoke negatively affects the synthesis of n−3 LC‐PUFA from the precursor in mammary gland cells.
β‐oxidation, esterification, and secretion of radiolabeled fatty acids in cultivated atlantic salmon skeletal muscle cells
Authors: Vegusdal A. , Østbye T. K. , Tran T. ‐N. , Gjøen T. , Ruyter B.
Published: November 2006

The white muscle of Atlantic salmon metabolizes FA with different chain lengths and different saturations at different rates, but few details are available on the processes involved or the products formed. We have investigated how multinucleated muscle cells (myotubes) in culture metabolize [1‐14C]8∶0, [1‐14C]18∶1n−9, and [1‐14C]20∶5n−3. The myotubes were formed by the differentiation of isolated myosatellite cells from the white skeletal muscle of salmon fry. Almost all (98%) of the [1‐14C]8∶0 substrate was oxidized to acid‐soluble products (ASP) and 14CO2 after 48 h of incubation, whereas only approximately 50% of the [1‐14C]18∶1n−9 and [1‐14C]20∶5n−3 substrates were oxidized. However, only one cycle of β‐oxidation was measured by the method used. For all three substrates, the main ASP were acetate and a combined fraction of oxaloacetate and malate. Nearly twice as much radioactivity from the [1‐14C]20∶5n−3 substrate was found in the cellular lipids as radioactivity from [1‐14C]18∶1n−9, indicating that [1‐14C]20∶5n−3 was taken up into muscle cells more rapidly than [1‐14C]18∶1n−9. Approximately 10% of the added [1‐14C]20∶5n−3 substrate and 5% of the added [1‐14C]18∶1n−9 substrate was secreted from the muscle cells into the culture media as esterified lipids. Immunocytochemical staining showed that the cells synthesized apolipoprotein A‐I. Differentiated muscle cells also expressed peroxisome proliferator‐activated receptor α (PPARα) and PPARβ, two transcription factors that are involved in regulating β‐oxidation.
2‐Methoxylated fatty acids in marine sponges: Defense mechanism against mycobacteria?
Authors: Carballeira Néstor M. , Cruz Heindyleen , Kwong Cecil D. , Wan Baojie , Franzblau Scott
Published: November 2006

A series of saturated 2‐methoxylated FA having even‐numbered chains with 8–14 carbons were synthesized, and their spectroscopic data are presented for the first time. The 2‐methoxylated C10−C14 acids were prepared from the corresponding 2‐hydroxylated FA, whereas the 2‐methoxyoctanoic acid was synthesized starting with heptaldehyde. All of the methoxylated FA displayed some degree of inhibition (between 2 and 99%) of Mycobacterium tuberculosis H37Rv at 6.25 μg/mL. The most inhibitory FA was 2‐methoxydecanoic acid, with a minimum inhibitory concentration of 200–239 μM against M. tuberculosis H37Rv as determined by both the microplate Alamar Blue assay and the green fluorescent protein microplate assay. These results are discussed in terms of the possible role of the 2‐methoxylated FA as antimicrobial lipids produced either by marine sponges, or the associated marine symbiotic bacteria, as a defense mechanism in a highly competitive environment.
Unusual C21 linear polyacetylenic alcohols from an Atlantic ascidian
Authors: Gavagnin Margherita , Castelluccio Francesco , Antonelli Angelo , Templado Josè , Cimino Guido
Published: November 2006

Four novel straight‐chain polyacetylenic alcohols were isolated from a marine ascidian (Phylum Chordata, subphyllum Urochordata) collected off Vigo, along the Atlantic coast of northwestern Spain. The chemical structures, which exhibit an uncommon dienyne group, were characterized by spectroscopic methods, mainly mono‐ and bi‐dimensional NMR. This is the first finding of acetylenic lipids from an organism belonging to phylum Chordata.
The effect of α‐linolenic acid and linoleic acid on the growth and development of formula‐fed infants: A systematic review and meta‐analysis of randomized controlled trials
Authors: Udell Tuesday , Gibson Robert A. , Makrides Maria ,   PUFA Study Group
Published: November 2006

This systematic review and meta‐analysis aimed to evaluate the effect of modifying 18‐carbon PUFA [18‐C PUFA: α‐linolenic acid (ALA, 18∶3n−3) and linoleic acid (LA, 18∶2n−6)] in the diets of term and preterm infants on DHA (22∶6n−3) status, growth, and developmental outcomes. Only randomized controlled trials (RCT) involving formula‐fed term and preterm infants, in which the 18‐C PUFA composition of the formula was changed and growth or developmental outcomes were measured, were included. Differences were presented as control (standard formula) and treatment (18‐C PUFA‐supplemented formula). Primary analyses for term infants were 4 and 12 mon and for preterm infants 37–42 and 57 wk postmenstrual age. Five RCT involving term infants and three RCT involving preterm infants were included in the systematic review. Infants fed ALA‐supplemented formula had significantly higher plasma and erythrocyte phospholipid DHA levels than control infants. There was no effect of ALA supplementation on the growth of preterm infants. In term infants, ALA supplementation was associated with increased weight and length at 12 mon, which was at least 4 mon after the end of dietary intervention. Developmental indices of term infants did not differ between groups. There was a transient improvement in the retinal function of preterm infants fed ALA‐supplemented diets compared with controls. The findings suggest that ALA‐supplemented diets improve the DHA status of infants. Further studies are needed to provide convincing evidence regarding the effects of ALA supplementation of formula on infant growth and development.
Molecular evidence that the rate‐limiting step for the biosynthesis of arachidonic acid in Mortierella alpina is at the level of an elongase
Authors: Takeno Seiki , Sakuradani Eiji , Murata Shoichi , Inohara‐Ochiai Misa , Kawashima Hiroshi , Ashikari Toshihiko , Shimizu Sakayu
Published: November 2006

The oil‐producing fungus Mortierella alpina 1S‐4 is an industrial strain for arachidonic acid (AA) production. To determine its physiological properties and to clarify the biosynthetic pathways for PUFA, heterologous and homologous gene expression systems were established in this fungus. The first trial was performed with an enhanced green fluorescent protein gene to assess the transformation efficiency for heterologous gene expression. As a result, strong fluorescence was observed in the spores of the obtained transformant, suggesting that the foreign gene was inherited by the spores. The next trial was performed with a homologous PUFA elongase (GLELOp) gene, this enzyme having been reported to catalyze the elongation of GLA (18∶3n−6) to dihomo‐γ‐linolenic acid (20∶−6), and to be the rate‐limiting step of AA production. The FA composition of the transformant was different from that of the host strain: The GLA content was decreased whereas that of AA was increased. These data support the hypothesis that the GLELOp enzyme plays an important role in PUFA synthesis, and may indicate how to control PUFA biosynthesis.
Over‐expression of hepatic neutral cytosolic cholesteryl ester hydrolase in mice increases free cholesterol and reduces expression of HMG‐CoAR, CYP27, and CYP7A1
Authors: Langston Timothy B. , Hylemon Phillip B. , Grogan W. M.
Published: November 2006

Hepatic neutral cytosolic cholesteryl ester hydrolase (hncCEH) is a key enzyme in the regulation of hepatic free cholesterol (FC). In examining the effects of over‐expression of this enzyme on cholesterol homeostasis, mice were infected with a recombinant adenovirus construct (AdCEH) of the rat hncCEH cDNA driven by the human cytomegalovirus promoter. Cholesteryl esterase and p‐nitrophenylcaprylate (PNPC) esterase activities were measured in liver postmitochondrial supernatants at 1, 3, 7, and 11 d after infection with AdCEH or a control virus expressing β‐galactosidase (AdβGAL). The PNPC esterase activity of AdCEH mice peaked threefold higher than controls on day 2, declining on subsequent days. In contrast, cholesteryl esterase peaked eightfold higher than controls on day 3, indicating a shift in substrate selectivity of hncCEH. Hepatic FC peaked at 144% of controls, 7 d postinfection. The mRNAs for cholesterol 7α‐hydroxylase, sterol 27‐hydroxylase, and HMG‐CoA reductase decreased to 47, 46, and 58% of controls, respectively, on day 7, coinciding with peak FC concentrations. Coiniding with increased cholesteryl esterase activity, hepatic esterified cholesterol dropped precipitously from day 3 onward, to 11% of controls by day 11. Hepatic TAG levels also declined, consistent with the reported TAG lipase activity of hncCEH. These results demonstrate elevation of FC and depletion of cholesteryl esters by over‐expression of hncCEH, which were resistant to compensatory responses by other enzymes of cholesterol homeostasis.
Sulfur‐substituted and α‐methylated fatty acids as peroxisome proliferator‐activated receptor activators
Authors: Larsen Laila N. , Granlund Linda , Holmeide Anne Kristin , Skattebøl Lars , Nebb Hilde Irene , Bremer Jon
Published: November 2006

FA with varying chain lengths and an α‐methyl group and/or a sulfur in the β‐position were tested as peroxisome proliferator‐activated receptor (PPAR)α,‐δ(β), and‐γ ligands by transient transfection in COS‐1 cells using chimeric receptor expression plasmids, containing cDNAs encoding the ligand‐binding domain of PPARα,‐δ, and‐γ. For PPARα, an increasing activation was found with increasing chain length of the sulfur‐substituted FA up to C14‐S acetic acid (tetradecylthioacetic acid=TTA). The derivatives were poor, and nonsignificant, activators of PPARδ. For PPARγ, activation increased with increasing chain length up to C16‐S acetic acid. A methyl group was introduced in the α‐position of palmitic acid, TTA, EPA, DHA, cis9,trans11CLA, and trans10,cis12 CLA. An increased activation of PPARα was obtained for the α‐methyl derivatives compared with the unmethylated FA. This increase also resulted in increased expression of the two PPARα target genes acyl‐CoA oxidase and liver FA‐binding protein for α‐methyl TTA, α‐methyl EPA, and α‐methyl DHA. Decreased or altered metabolism of these derivatives in the cells cannot be excluded. In conclusion, saturated FA with sulfur in the β‐position and increasing carbon chain length from C9−S acetic acid to C14−S acetic acid have increasing effects as activators of PPARα and‐γ in transfection assays. Furthermore, α‐methyl FA derivatives of a saturated natural FA (palmitic acid), a sulfur‐substituted FA (TTA), and PUFA (EPA, DHA, c9,t11 CLA, and t10,c12 CLA) are stronger PPARα activators than the unmethylated compounds.
High‐fat diets impede the lowering effect of cyclosporine a on rat brain lipids and interact with the expression of apolipoproteins E and J
Authors: Montpied Pascale , Domingo Nicole , Senft Michèle , Portugal Henri , Petit Pierre , Chanussot Françoise
Published: November 2006

Cyclosporine A (CsA), a common immunosuppressive agent, produces hyperlipidemia and apolipoprotein profile alterations in plasma as well as neurological and psychiatric complications. In rats, 10 mg CsA/kg/d treatments for 3 wk induce alterations of the electroencephalogram, and of the blood and brain lipids. Using this model, we evaluated whether triacylglycerol (TG)‐ and lecithin (PC)‐enriched diets, reported to decrease epileptic episodes (TG) and to improve memory, could modify the effects of CsA treatment on brain lipids and possibly change apolipoprotein (apo) E and apoJ gene expression. To evaluate this hypothesis, three groups of rats were treated for 3 wk with CsA and received a low‐fat, PC, or TG diet. Three other groups were fed the above‐mentioned diets and were treated with the CsA solvent. As a control, one group was fed only the low‐fat diet. The CsA‐mediated decreases in brain cholesterol and PC contents, under a low‐fat diet, were eliminated by the TG and PC diets. These high‐fat diets induced a global increase in hippocampal transcriptional activity, as revealed by elevated polyadenylated RNA levels. The apoE and apoJ mRNA levels in the cortex and hippocampus of rats receiving the solvent were not statistically different between the TG‐ and PC‐enriched diets but showed important variations compared with the low‐fat diet solvent‐treated group. A differential effect between the two high‐fat diets was obsorved in the hippocampus, resulting in a significant increase of the apoE to apoJ ratio with the PC diet. The balance between apoE and apoJ is presumed to be important in encephalopathic mechanisms, by its involvement through low levels of brain cholesterol and PC, that might be associated with mental disorders. Our results therefore suggest that diet enrichment with polyunsaturated fat might be beneficial during CsA therapy. However, if the high levels in PC used here are more beneficial on CsA peripheral side effects than similar enrichment in TG, this does not seem to be the case in the brain. Thus, lower levels in PC should be tested.
Molecular cloning, expression, and characterization of secretory phospholipase A2 in tobacco
Authors: Fujikawa Ritsuko , Fujikawa Yukichi , Iijima Noriaki , Esaka Muneharu
Published: November 2006

Phospholipase A2 (PLA2) activity was investigated in various tissues of tobacco (Nicotiana tabacum). PLA2 activity in the flower was 15 times higher than that in the leaf, stem, and root. PLA2 activity in the flower appears to have originated from both Ca2+‐dependent and‐independent PLA2. A cDNA clone for protein with homology to animal secretory PLA2 (sPLA2), denoted as Nt PLA2, was isolated from the tobacco flower. The cDNA of Nt PLA2 encoded a mature protein of 127 amino acid residues with a putative signal peptide of 30 residues. The amino acid sequence for mature Nt PLA2 contains 12 cysteines, a Ca2+ binding loop, and a catalytic domain that are commonly conserved in animal sPLA2. The Nt PLA2 mRNA was mainly expressed in the root and stem of tobacco. The recombinant Nt PLA2 was expressed as a fusion protein with thioredoxin in Escherichia coli. From the bacterial cell lysate, the fusion protein was recovered in soluble form and cleaved by Factor Xa proteinase. Then the recombinant mature Nt PLA2 was purified by ion exchange chromatography. It was discovered that the purified Nt PLA2 essentially requires Ca2+, for the enzyme activity when the activity was determined using mixed‐micellar phospholipid substrates with sodium cholate. The optimal activity of Nt PLA2 was at pH 8–10 when PC was used as a substrate.
Dietary fish oil dose‐response effects on ileal phospholipid fatty acids and contractility
Authors: Patten Glen S. , Adams Michael J. , Dallimore A. , Abeywardena Mahinda Y.
Published: November 2006

We have reported that dietary fish oil (FO) leads to the incorporation of long‐chain n−3 PUFA into the gut tissue of small animal models, affecting contractility, particularly of rat ileum. This study examined the FO dose response for the incorporation of n−3 PUFA into ileal tissue and how this correlated with in vitro contractility. Groups of ten to twelve 13‐wk‐old Wistar‐Kyoto rats were fed 0, 1, 2.5, and 5% FO‐supplemented diets balanced with sunflower seed oil for 4 wk, after which ileal total phospholipid FA were determined and in vitro contractility assessed. For the total phospholipid fraction, increasing the dietary FO levels led to a significant increase first evident at 1% FO, with a stepwise, nonsaturating six‐fold increase in n−3 PUFA as EPA (20∶5n−3), DPA (docosapentaenoic acid, 22∶5n−3), and DHA, but mainly as DHA (22∶6n−3), replacing the n−6 PUFA linoleic acid (18∶2n−6) and arachidonic acid (20∶4n−6) over the dosage range. There was no difference in KCl‐induced depolarization‐driven contractility. However, a significant increase in receptor‐dependent maximal contractility occurred at 1% FO for carbachol and at 2.5% FO for prostaglandin E2, with a concomitant increase in sensitivity for prostaglandin E2 at 2.5 and 5% FO. These results demonstrate that significant increases in ileal membrane n−3 PUFA occurred at relatively low doses of dietary FO, with differential receptor‐dependent increases in contractility observed for muscarinic and prostanoid agonists.
Techniques for delivery of arachidonic acid to pacific oyster, Crassostrea gigas, spat
Authors: Seguineau C. , Soudant P. , Moal J. , Delaporte M. , Miner P. , Quéré C. , Samain J. ‐F.
Published: November 2006

The present study tested two techniques for dietary supplementation of Crassostrea gigas spat with PUFA, such as arachidonic acid (AA). The first technique consisted of a preliminary enrichment and growth of an algal concentrate (T‐ISO, Isochrysis sp.) with AA dissolved in an ethanol solution, the whole culture then being fed to the spat. This enrichment increased the AA weight percentage in T‐ISO neutral and polar lipids from 0.6 to 22.4% and from 0.4 to 6.8%, respectively. The second delivery technique was direct addition separately of free AA dissolved in ethanol solution and algal concentrate (T‐ISO+AA) to the spat‐rearing tank. To test the efficiency of these delivery techniques, oyster spat were supplemented with AA‐enriched T‐ISO, T‐ISO+AA, and T‐ISO alone. The possible biological impacts of these dietary treatments were assessed by measuring growth, condition index, and TAG content of oyster spat. Dry weight and condition index of spat fed AA‐enriched T‐ISO decreased by 24 and 49%, respectively, after 26 d of feeding; basically, TAG content declined 88% after 34 d of conditioning. When AA was added directly to seawater, spat growth and condition index were comparable with those of oysters fed T‐ISO alone. AA incorporation in oyster tissues was assessed by analysis of the FA compositions in both neutral and polar lipid fractions. After 34 d, AA content in neutral lipids reached 7 and 11.7% in the spat fed, respectively, AA‐enriched T‐ISO and T‐ISO+AA, as compared with 1.1% in spat fed only T‐ISO. AA incorporation was greater in polar lipids than in neutral lipids, reaching 7.8 and 12.5% in spat fed AA‐enriched T‐ISO and T‐ISO+AA, respectively. A direct addition of PUFA along with the food supply represents an effective and promising means to supplement PUFA to oyster spat.
High docosahexaenoic acid levels in both neutral and polar lipids of a highly migratory fish: Thunnus tonggol (Bleeker)
Authors: Saito Hiroaki , Seike Yutaka , Ioka Hisashi , Osako Kazufumi , Tanaka Mikiko , Takashima Akihito , Keriko Joseph M. , Kose Sevim , Souza Juan C. Rodriguez
Published: November 2006

The lipid and FA compositions of various organs (light muscle, dark muscle, liver, pyloric cecum, and the orbital region) and of the stomach contents of a highly migratory fish species Thunnus tonggol (Bleeker) were analyzed. TAG and phospholipids (PE and PC) were the major lipid classes in the total lipids of T. tonggol. DHA was characteristically the major FA of all the major classes of all its organs except for only one case of liver TAG. The mean DHA contents of the various organs accounted for more than 20% of the total FA (TFA), even though it is a neutral depot lipid. However, DHA in the stomach contents, originating from their prey, fluctuated and was generally low. DHA levels were generally higher in a year (2000) when water temperatures were colder than in one when it was warmer (1998). Furthermore, DHA levels in muscle TAG were consistently high in spite of the fluctuation of those in the visceral TAG, which might be directly influenced by the prey lipids. This phenomenon suggests the physiological selective accumulation of DHA in the muscle, after the migration of the digested FA in the vascular system and absorption of the prey lipids in the intestine. In contrast, the FA composition of other species is generally variable and their DHA contents of TAG are usually less than 20% of TFA.
Sesamol induces nitric oxide release from human umbilical vein endothelial cells
Authors: Chen Pey‐Rong , Tsai Chingmin E. , Chang Hang , Liu Tsuei‐Ling , Lee Chun‐Chung
Published: November 2006

Sesamol, which is derived from sesame seed lignans, is reportedly an antioxidant. Nitric oxide (NO), the most important vascular relaxing factor, is regulated in the endothelium. In addition, NO is involved in protecting endothelium and has antiatherosclerotic and antithrombotic activities. The endothelium produces NO through the regulation of both endothelial NO synthase (eNOS) expression and activity in endothelial cells. This study sought to investigate the effect of sesamol on NO released from human umbilical vein endothelial cells (HUVEC) and to examine the expression and activity of eNOS. Sesamol induced NO release from endothelial cells in a dose‐dependent manner (from 1 to 10 μM), as measured 24 h after treatment; the expression of the eNOS gene at both transcription and translation levels; and NOS activity in endothelial cells. The content of cGMP was also increased by sesamol through NO signaling. The transcription of eNOS induced by sesamol was confirmed through the activation of PI‐3 kinase‐Akt (protein kinase B) signaling. The results demonstrate that sesamol induces NOS signaling pathways in HUVEC and suggest a role for sesamol in cardiovascular reactivity in vivo.
Trans and positional ethylenic bonds in two dominant isomers of eicosapentaenoic acid from the freshwater sponge Baicalospongia bacillifera
Authors: Imbs Andrey B. , Rodkina Svetlana A.
Published: November 2006

Reinvestigation of the current FA composition of the regional freshwater sponge Baicalospongia bacillifera showed that the main measured isomer of EPA (14% of the total FA now detected) is, in fact, an unusual 5Z,8Z,11Z,14Z,18E‐EPA. Two other isomers of this acid also present were identified as a novel 5Z,8Z,11Z,15Z,18E‐EPA and the common methylene‐interrupted 5Z,8Z,11Z,14Z,17Z‐EPA (usually written simply as EPA). Isolation of these acids as their methyl ester derivatives was accomplished with the use of a combination of silver‐ion column chromatography and HPLC. The structure of the two new compounds was deduced from GC‐MS and detailed NMR data. Partial hydrazine reduction of all three isolated EPA esters followed by separation of cis/trans isomers of the resulting monoenoic acids and GC‐MS analysis of their dimethyl disulfide adducts were used for determination of the configuration and position of the double bonds. We may assume that the sponge B. bacillifera cannot receive these unusual EPA isomers directly from food sources (e.g., algal diatoms), and accordingly restructuring of ordinary EPA to novel acids may take place in the sponge tissue.
New fatty acid derivatives fromHomaxinellasp., a marine sponge
Authors: Mansoor Tayyab A. , Bae Bok Hee , Hong Jongki , Lee Chong‐O. , Im Kwang Sik , Jung Jee H.
Published: November 2006

Fractionation of the MeOH extract ofHomaxinellasp., a marine sponge, led to the isolation of a sodium salt of a new brominated FA (1), two new MG (2and4), and a new lysoPC (6). The geometry of the double bonds in1and2was defined by comparison of the NMR chemical shifts of the allylic carbons, nuclear Overhauser effect spectroscopy correlations of the allylic protons, and coupling constants of the vinylic protons with those reported. Evidence mainly from NMR and MS analyses established the planar structures of the compounds. Compounds1, 2, 4, and6were evaluated for cytotoxicity against a panel of five human solid tumor cell lines. Only compound1showed moderate activity.
Pathways for fatty acid elongation and desaturation in Neurospora crassa
Authors: McKeon Thomas A. , Goodrich‐Tanrikulu Marta , Lin Jiann‐Tsyh , Stafford Allan
Published: November 2006

Neurospora crassa incorporated exogenous deuterated palmitate (16∶0) and 14C‐labeled oleate (18∶1Δ9) into cell lipids. Of the exogenous 18∶1Δ9 incorporated, 59% was desaturated to 18∶2Δ9,12 and 18∶3Δ9,12,15. Of the exogenous 16∶0 incorporated, 20% was elongated to 18∶0, while 37% was elongated and desaturated into 18∶1Δ9, 18∶2Δ9,12, and 18∶3Δ9,12,15. The mass of unsaturated fatty acids in phospholipid and triacylglycerol is 12 times greater than the mass of 18∶0. Deuterium label incorporation in unsaturated fatty acids is only twofold greater than in 18∶0, indicating a sixfold preferential use of 16∶0 for saturated fatty acid synthesis. These results indicate that the release of 16∶0 from fatty acid synthase is a key control point that influences fatty acid composition in Neurospora.
Correlation of ATP/citrate lyase activity with lipid accumulation in developing seeds of Brassica napus L.
Authors: Ratledge Colin , Bowater Moray D. V. , Taylor Philip N.
Published: November 2006

The temporal distribution of ATP/citrate lyase (ACL) activity in developing seeds of Brassica napus L. closely paralleled both that of acetyl‐CoA carboxylase and the overall rate of lipid biosynthesis. Maximum ACL activities (250 nmol acetyl‐CoA formed min−1·g fresh seed) were recorded between 35 to 42 d after pollination and, if the in vitro data could be extrapolated to the situation in vivo, could account for half of the acetyl‐CoA required for the measured rate of fatty acid biosynthesis during seed development. The enzyme appeared to be localized in a subcellular compartment, which was clearly separated from mitochondria on a sucrose gradient and by differential centrifugation, and which corresponded to the chloroplast organelle.
Digestion of the 1‐O‐alkyl diacylglycerol ethers of atlantic dogfish liver oils by Atlantic salmon Salmo salar
Authors: Kang S. ‐J. , Lall S. P. , Ackman R. G.
Published: November 2006

Dogfish (Squalus acanthias) liver poses a waste disposal problem in Canada because it is not utilized for any commercial purpose. The liver of Atlantic dogfish, which is often up to 20% of the weight of the fish, contains 40–70% oil. The oil contains about 30–40% 1‐O‐alkyl diacylglycerol ethers (DAGE) which render it unacceptable for human use, and it has also not been considered satisfactory for animal feed use. Polyunsaturated fatty acids (20∶5n−3 and 22∶6n−3) are present in dogfish liver oils at levels comparable to those in herring oil. Dogfish liver oil could be a source of essential fatty acids for Atlantic salmon (Salmo salar), but their ability to hydrolyze DAGE from dogfish oil has not been examined. Experiments were designed to measure the digestibility of fatty acids of DAGE in salmon. The fatty acid moieties were liberated by the digestive enzymes of the fish and made readily available as a source of energy. The 1‐O‐alkylglycerol ether moiety was absorbed to a small extent but should not constitute a health problem in either the fish or the human fish consumer. The long‐chain polyunsaturated fatty acids were particulary well absorbed, with an apparent digestibility in salmon of 87–95% when feeding on dogfish liver oil. The total fatty acids and other lipids were in fact both absorbed to the extent of approximately 85%.
Synthesis of a novel vitamin E derivative, 2‐(α‐d‐glucopyranosyl)methyl‐2,5,7,8‐tetramethylchroman‐6‐ol, by α‐glucosidase‐catalyzed transglycosylation
Authors: Murase Hironobu , Yamauchi Ryo , Kato Koji , Kunieda Tsutomu , Terao Junji
Published: November 2006

A novel derivative of vitamin E, vitamin E glucoside, was synthesized from 2‐hydroxymethyl‐2,5,7,8‐tetramethylchroman‐6‐ol and maltose in a solution containing DMSO by transglycosylation with α‐glucosidase from Saccharomyces species. The glycosylated product was identified as 2‐(α‐d‐glucopyranosyl)methyl‐2,5,7,8,‐tetramethylchroman‐6‐ol (TMG) by mass spectrometry and nuclear magnetic resonance spectroscopy. The optimal pH of transglycosylation was 5.5, and the yield of TMG increased as the concentration of maltose increased. IMG has high solubility in water (>1×103 mg/mL). The 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity of TMG was found to be nearly the same as those of α‐tocopherol, Trolox (2‐carboxy‐2,5,7,8‐tetramethylchroman‐6‐ol), and ascorbic acid.
Biotransformations of tocopherols by Streptomyces catenulae
Authors: Rousseau Brigitte , Dostal Larry , Rosazza John P. N.
Published: November 2006

Streptomyces catenulae catalyzed the oxidation of α‐tocopherol to α‐tocopherolquinone. Nitrotocopherols isolated from S. catenulae grown in defined culture medium containing δ‐and γ‐tocopherols are formed by a combination of enzymatic nitrate reduction to nitrite, and subsequent nonenzymatic acid‐catalyzed nitration. The incorporation of 15N18O3‐into nitrated tocopherols confirmed the origin of the nitrating species. Structures of chromatographically purified products obtained from S. catenulae transformations of tocopherols were deduced by spectral (mass spectrometry, 1H‐, and 13C‐nuclear magnetic resonance) analyses.
Analysis of hydroxy and keto cholesterols in oxidized brain synaptosomes
Authors: Vatassery Govind T. , Quach Hung T. , Ed Smith W. , Krick Thomas P. , Ungar Frank
Published: November 2006

A rapid method for the simultaneous determination of cholesterol and its oxidation products as well as α‐tocopherol and tocopherolquinone in brain subcellular fractions is described. The samples are saponified and extracted with hexane. It is not necessary to remove cholesterol in the sample before analyzing for oxysterols. The hexane extract can be used for the assay of cholesterol compounds by capillary gas chromatography and tocopherol compounds by liquid chromatography using a procedure reported previously. Oxidation of synaptosomes by a mixture of Fe2+ plus ascorbate resulted in the production of 7‐keto‐, 7α‐hydroxy‐, 7β‐hydroxy‐, and 5α, 6α‐epoxycholesterols. The identities of these products were confirmed with gas chromatography/mass spectrometry. Cholesterol oxidase treatment did not result in the formation of any of the above compounds. Thus the types and amounts of the products of oxidation of cholesterol were dependent upon the oxidizing agent. Extraction of the oxysterols under milder conditions without saponification using sodium dodecyl sulfate cannot be used since such treatment results in low recovery of oxysterols. Oxidation of synaptosomes by low concentrations of ferrous iron and ascorbate resulted in (i) low levels of oxidation of cholesterol which could be followed by estimating the production of oxysterols and (ii) oxidation of a substantial percentage of α‐tocopherol. The proposed procedure will be useful in monitoring the oxidation of small quantities of membrane cholesterol in vitro.
The effects of infusion of trieicosapentaenoyl‐glycerol emulsion on extravascular lung water during myocardial ischemia and reperfusion in dogs
Authors: Izuoka Toshio , Kimura Yutaka , Hamazaki Tomohito , Tamura Teruhiro , Kitashiro Shuji , Sugiura Tetsuro , Jikuhara Toshimitsu , Iwasaka Toshiji
Published: November 2006

To test the effects of eicosapentaenoic acid (EPA) infusion on pulmonary edema induced by coronary ligation and reperfusion, extravascular lung water (EVLW) was measured in situ by the thermal‐dye double indicator dilution method in dogs. In the control group of five dogs, 30 mL of a 10% soybean oil emulsion was infused through a leg vein. One hour after infusion, the left anterior descending coronary artery below the first diagonal branch was ligated for 15 min and then reperfused for 30 min. In the EPA group, six dogs were similarly treated with an emulsion of a 10% trieicosapentaenoyl‐glycerol (90% pure). EVLW, pulmonary capillary wedge pressure, mean pulmonary artery pressure, mean blood pressure, and cardiac index were measured before and 15 min after coronary ligation, and 15 min and 30 min after coronary reperfusion. There were no significant differences in the hemodynamic indices between the two groups. EVLW significantly increased up to two times of baseline during coronary ligation in the control group (P< 0.05) and more during reperfusion (P<0.01), whereas EVLW did not increase in the EPA group. In conclusion, EPA inhibited EVLW accumulation and may be useful for ameliorating one of the ischemia‐reperfusion‐induced complications, pulmonary edema.
Altered acyl chain length specificity of Rhizopus delemar lipase through mutagenesis and molecular modeling
Authors: Klein Robert R. , King Gregory , Moreau Robert A. , Haas Michael J.
Published: November 2006

The acyl binding site of Rhizopus delemar prolipase and mature lipase was altered through site‐directed mutagenesis to improve lipase specificity for short‐or medium‐chain length fatty acids. Computer‐generated structural models of R. delemar lipase were used in mutant protein design and in the interpretation of the catalytic properties of the resulting recombinant enzymes. Molecular dynamics simulations of the double mutant, val209trp+phe112trp, predicted that the introduction of trp112 and trp209 in the acyl binding groove would sterically hinder the docking of fatty acids longer than butyric acid. Assayed against a mixture of triacylglycerol substrates, the val209trp+phe112trp mature lipase mutant showed an 80‐fold increase in the hydrolysis of tributyrin relative to the hydrolysis of tricaprylin while no triolein hydrolysis was detected. By comparison, the val94Trp mutant, predicted to pose steric or geometric constraints for docking fatty acids longer than caprylic acid in the acyl binding groove, resulted in a modest 1.4‐fold increase in tricaprylin hydrolysis relative to the hydrolysis of tributyrin. Molecular models of the double mutant phe95asp+phe214arg indicated the creation of a salt bridge between asp95 and arg214 across the distal end of the acyl binding groove. When challenged with a mixture of triacylglycerols, the phe95asp+phe214arg substitutions resulted in an enzyme with 3‐fold enhanced relative activity for tricaprylin compared to triolein, suggesting that structural determinants for medium‐chain length specificity may reside in the distal end of the acyl binding groove. Attempts to introduce a salt bridge within 8 Å of the active site by the double mutation leu146lys+ser115asp destroyed catalytic activity entirely. Similarly, the substitution of polar Gln at the rim of the acyl binding groove for phe 112 largely eliminated catalytic activity of the lipase.
Peroxidase‐catalyzed oxidation of β‐carotene in HL‐60 cells and in model systems: Involvement of phenoxyl radicals
Authors: Tyurin Vladimir A. , Carta Gianfranca , Tyurina Yulia Y. , Banni Sebastiano , Day Billy W. , Corongiu Francesco P. , Kagan Valerian E.
Published: November 2006

Recent studies provide extensive evidence for the importance of carotenoids in protecting against oxidative stress associated with a number of diseases. In particular, reactions of carotenoids with phenoxyl radicals generated by peroxidasecatalyzed one‐electron metabolism of phenolic compounds may represent an important antioxidant function of carotenoids. To further our understanding of the antioxidant mechanisms of carotenoids, we used in the present work two different phenolic compounds, phenol and a polar homologue of vitamin E (2,2,5,7,8‐pentamethyl‐6‐hydroxychromane, PMC), as representatives of two different types of phenols to study reactions of their respective phenoxyl radicals with carotenoids in cells and in model systems. We found that phenoxyl radicals of PMC did not oxidize β‐carotene in either HL‐60 cells or in model systems with horseradish peroxidase (HRP)/H2O2. In contrast, the phenoxyl radicals generated from phenol (by native myeloperoxidase in HL‐60 cells or HRP/H2O2 in model systems) effectively oxidized β‐carotene and other carotenoids (canthaxanthin, lutein, lycopene). One‐electron reduction of the phenoxyl radical by ascorbate (assayed by electron spin resonance‐detectable formation of semidehydroascorbyl radicals) prevented HRP/H2O2‐induced oxidation of β‐carotene. PMC, but not phenol, protected β‐carotene against oxidation induced by a lipid‐soluble azo‐initiator of peroxyl radicals. No adducts of peroxidase/phenol/H2O2‐induced β‐carotene oxidation intermediates with phenol were detected by high‐performance liquid chromatography‐mass spectrometry analysis of the reaction mixture. Since carotenoids are essential constituents of the antioxidant defenses in cells and biological fluids, their depletion through the reaction with phenoxyl radicals formed from endogenous, nutritional and environmental phenolics, as well as phenolic drugs, may be an important factor in the development of oxidative stress.