bluuebunny/crossref_metadata_2025 huggingface dataset:
The metabolism and n−6/n−3 ratio of essential fatty acids in rats: Effect of dietary arachidonic acid and a mixture of sesame lignans (sesamin and episesamin)
Authors: Umeda‐Sawada Rumi , Ogawa Megumi , Igarashi Osamu
Published: November 2006

In this study, we examined the effect of dietary arachidonic acid (AA) and sesame lignans on the content and n‐6/n‐3 ratio of polyunsaturated fatty acid (PUFA) in rat liver and the concentrations of triglyceride (TG) and ketone bodies in serum. For 4 wk, rats were fed two types of dietary oils: (i) the control oil diet groups (CO and COS): soybean oil/perilla oil=5∶1, and (ii) the AA‐rich oil group (AO and AOS): AA ethyl esters/palm oil/perilla oil=2∶∶1, with (COS and AOS) or without (CO and AO) 0.5% (w/w) of sesame lignans. Dietary AA and sesame lignans significantly affected hepatic PUFA metabolism. AA content and n‐6/n‐3 ratio in the liver were significantly increased in the AO group, despite the dietary total of n‐6 PUFA being the same in all groups, while AOS diet reduced AA content and n‐6/n‐3 ratio to a level similar to the CO and COS groups. These results suggest that (i) dietary AA considerably affects the hepatic profile and n‐6/n‐3 ratio of PUFA, and (ii) dietary sesame lignans reduce AA content and n‐6/n‐3 ratio in the liver. In the AO group, the concentration of acetoacetate was significantly increased, but the ratio of β‐hydroxybutyrate/acetoacetate was decreased. On the other hand, the AO diet increased the concentration of TG in serum by almost twofold as compared to other groups. However, the AOS diet significantly reduced serum IG level as compared to the AO group. In addition, the AOS diet signicantly increased the acetoacetate level, but reduced the β‐hydroxybutyrate/acetoacetate ratio. These results suggest that dietary sesame lignans promote ketogenesis and reduce PUFA esterification into TG. This study resulted in two findings: (i) sesame lignans inhibited extreme changes of the n‐6/n‐3 ratio by reducing hepatic PUFA content, and (ii) the reduction of hepatic PUFA content may have occurred because of the effects of sesame lignans on PUFA degradation (oxidation) and esterification.
Dietary cyanidin 3‐O‐β‐d‐glucoside increases ex vivo oxidation resistance of serum in rats
Authors: Tsuda Takanori , Horio Fumihiko , Osawa Toshihiko
Published: November 2006

The effect of dietary cyanidin 3‐O‐β‐d‐glucoside (C3G), a typical anthocyanin pigment, on the generation of thiobarbituric acid reactive substances (TBARS) during serum formation ex vivo and susceptibility of serum to further lipid peroxidation was studied in rats. Rats were fed a diet containing C3G (2 g/kg) for 14 d. Feeding C3G resulted in a significant decrease in generation of TBARS during serum formation. The serum from the C3G‐fed group showed a significantly lower susceptibility to further lipid peroxidation provoked by 2,2′‐azobis (2‐amidinopropane)hydrochloride or Cu2+ than that of the control group. No significant differences were observed in serum phospholipid, triglyceride, esterified cholesterol, and free fatty acid concentrations between the control and the C3G‐fed groups. Concentrations of endogenous antioxidants remaining in the serum after blood coagulation were not affected by the C3G feeding. These results demonstrate that feeding C3G increases the ex vivo oxidation resistance of the serum without affecting serum endogeneous antioxidant levels, and reduces the TBARS generated during serum formation without changing the concentrations of serum lipids.
Protective effect of a vitamin E analog, phosphatidylchromanol, against oxidative hemolysis of human erythrocytes
Authors: Koga Takuro , Moro Keiko , Terao Junji
Published: November 2006

The protective effect of a vitamin E analog, phosphatidylchromanol [1,2‐diacyl‐sn‐glycero‐3‐phospho‐2′‐(hydroxyethyl)‐2′, 5′,7′,8′‐tetramethyl‐6′‐hydroxychroman; PCh], against oxidative hemolysis of human erythrocytes was examined and was compared with those of vitamin E (α‐tocopherol) and 2,2,5,7,8‐pentamethyl‐6‐chromanol (PMC). These three compounds at 50 μM protected the erythrocytes from hemolysis, when erythrocyte suspension (10%, vol/vol) was incubated with a water‐soluble radical generator, 2,2′‐azobis(2‐amidino‐propane)‐dihydrochloride (75 mM). When erythrocyte suspension was oxidized after pretreatment with these compounds (50 μM) for 30 min followed by washing, PCh protected about 54% of erythrocytes from the hemolysis, while α‐tocopherol protected only about 16% of the cells and PMC did not show any protective effect. During preincubation, α‐tocopherol, PMC, and PCh were incorporated into the cells at the concentration of 12.6, 3.7, and 16.3 nmol/mg protein, respectively. Moreover, PCh was found in the ghost membrane fraction at a 20% higher level than α‐tocopherol, and no PMC was detected in this fraction. These results indicate that phosphatidyl group in PCh accts as an excellent carrier of chromanol moiety into cells as well as an anchor within membranes more efficiently than phytyl group in α‐tocopherol. PMC seems to be slightly anchored within membranes because of the lack of hydrophobic side chain. The excellent antihemolytic activity of PCh is likely to be caused by its accumulation within erythrocyte membranes.
N‐Stearoyl‐phosphatidylserine: Synthesis and role in divalent‐cation‐induced aggregation and fusion
Authors: Morillo Margarita , Sagristá M. Luisa , de Madariaga M. Africa
Published: November 2006

N‐Acylphosphatidylserines have been isolated from intact and injured tissues, but the participation of such acidic phospholipids in membrane aggregation and fusion has not been demonstrated. We have synthesized N‐stearoylphosphatidylserine (NSPS) and examined divalent‐cation‐induced aggregation of NSPS‐liposomes, which leads to membrane destabilization and fusion. The purified lipid was characterized by its chromatographic and spectroscopic (infrared and 1H nuclear magnetic resonance) properties and by its chemical degradation pattern. Aggregation of unilamellar NSPS‐liposomes was studied as a function of calcium and magnesium concentration. The ability of calcium and magnesium to induce vesicle aggregation is higher for phosphatidylserine (PS)‐liposomes (threshold concentration 1.5 mM for calcium and 4.6 mM for magnesium) than for NSPS‐liposomes (threshold concentration 2.8 mM for calcium and 6.6 mM for magnesium). The irreversibility of the aggregation reactions after adding EDTA suggests that vesicle fusion might occur in the presence of calcium and magnesium. Preliminary studies, based on mixing of both lipid and internal aqueous contents, show that fusion rather than aggregation of NSPS‐liposomes occurs in the presence of calcium ions. The tendency of NSPS‐liposomes to aggregate at higher cation concentrations than PS‐liposomes suggests that N‐acylation of phosphatidylserine protects the membrane against degenerative damage caused by aggregation and fusion.
Long‐chain alkenes of the haptophytes Isochrysis galbana and Emiliania huxleyi
Authors: Rieley Gareth , Teece Mark A. , Peakman Torren M. , Raven Anthony M. , Greene Kirstie J. , Clarke Timothy P. , Murray Martin , Lettley John W. , Campbell Catherine N. , Harris Roger P. , Parkes R. John , Maxwell James R.
Published: November 2006

The major alkenes of the haptophytes Isochrysis galbana (strain CCAP 927/14) and Emiliania huxleyi (strains CCAP 920/2 and VAN 556) have been identified by nuclear magnetic resonance spectroscopy and by mass spectrometric analysis of their dimethyl disulfide adducts. The dominant alkene in I. galbana is (22Z)‐1,22‐hentriacontadiene, with 1,24‐hentriacontadiene and 1,24‐tritriacontadiene present in much lower abundance; (22Z)‐1,22‐hentriacontadiene also occurs in E. huxleyi (strain CCAP 920/2), together with (2Z,22Z)‐2,22‐hentriacontadiene (the major hydrocarbon) and (3Z,22Z)‐3,22‐hentriacontadiene. Minor abundances of 2,24‐hentriacontadiene and 2,24‐tritriacontadiene are also present in this strain. In contrast, the dominant alkene in E. huxleyi (strain VAN 556) is (15E,22E)‐1,16,23‐heptatriacontatriene with the related alkatriene 1,15,22‐octatriacontatriene also present and (22Z)‐1,22‐hentriacontadiene occurring as a minor component. From structural relationships (15E,22E)‐1,15,22‐heptatriacontatriene is proposed to derive from the same biosynthetic pathway as that of the characteristic C37 alkenones which occur in both E. huxleyi and I. galbana. The C31 and C33 dienes likely derive from chain extension and decarboxylation of (Z)‐9‐octadecenoic acid or (Z)‐7‐hexadecenoic acid, using a pathway analogous to that elucidated previously in the chlorophyte Botryococcus braunii. Therefore, long‐chain dienes and trienes, which can co‐occur in haptophytes, may have distinct biosynthetic pathways.
Epoxidation reactions of unsaturated fatty esters with potassium peroxomonosulfate
Authors: Lie Ken Jie Marcel S. F. , Pasha Mohammed Khysar
Published: November 2006

Epoxidation of the double bond in methyl oleate, octadec‐11E‐en‐9‐ynoate, ricinoleate (12‐hydroxy‐octadec‐9Z‐enoate), iso‐ricinoleate (9‐hydroxy‐octadec‐12Z‐enoate), and 12‐oxo‐octadec‐9Z‐enoate with potassium peroxomonosulfate (oxone, 2 KHSO5.K2SO4) in the presence of trifluoroacetone or methyl pyruvate gave the corresponding monoepoxy derivatives. Reaction of Oxone® with methyl linoleate and octadeca‐9Z,11E‐dienoate furnished the corresponding diepoxystearate derivative. Methyl 9,12‐dioxo‐octadec‐10Z‐enoate was obtained when a C18 furanoid fatty ester (methyl 9,12‐epoxy‐9,11‐octadecadienoate) was treated with Oxone®. The yield of these reactions was very high (85–99%), and the epoxy derivatives were readily isolated by solvent extraction. The products were identified by spectroscopic methods.
Callyspongynes A and B: New polyacetylenic lipids from a southern australian marine sponge, Callyspongia sp
Authors: Rooney Francis , Capon Robert J.
Published: November 2006

A Callyspongia sp. collected by SCUBA off Barwon Heads, Australia, has afforded two new polyacetylenic lipids, callyspongynes A and B, the structures of which were assigned by spectroscopic analysis and chemical derivatization.
Comparative effects of α‐ and γ‐linolenic acids on rat liver fatty acid oxidation
Authors: Kumamoto Tamotsu , Ide Takashi
Published: November 2006

It has been reported that both n−3 and n−6 octadecatrienoic acids can increase hepatic fatty acid oxidation activity. It remains unclear, however, whether different enzymes in fatty acid oxidation show a similar response to n−3 and n−6 octadecatrienoic acids. The activity of hepatic fatty acid oxidation enzymes in rats fed an oil mixture rich in α‐linolenic acid (18:3n−3) and borage oil rich in γ‐linolenic acid (18:3n−6) was therefore compared to that in rats fed an oil mixture rich in linoleic acid (18:2n−6) and a saturated fat (palm oil) in this study. Linseed oil served as the source of 18:3n−3 for the oil mixture rich in this octadecatrienoic acid and contained 30.6% 18:3n−3 but not 18:3n−6. Borage oil contained 25.7% 18:3n−6 and 4.5% 18:3n−3. Groups of seven rats each were fed diets containing 15% various fats for 15 d. The oxidation rate of palmitoyl‐CoA in the peroxisomes was higher in rats fed a fat mixture rich in 18:3n−3 (3.03 nmol/min/mg protein) and borage oil (2.89 nmol/min/mg protein) than in rats fed palm oil (2.08 nmol/min/mg protein) and a fat mixture rich in 18:2n−6 (2.15 nmol/min/mg protein). The mitochondrial palmitoyl‐CoA oxidation rate was highest in rats fed a fat mixture rich in 18:3n−3 (1.93 nmol/min/mg protein), but no significant differences in this parameter were seen among the other groups (1.25–1.46 nmol/min/mg protein). Compared to palm oil and fat mixtures rich in 18:2n−6, a fat mixture rich in 18:3n−3 and borage oil significantly increased the hepatic activity of carnitine palmitoyl‐transferase and acyl‐CoA oxidase. Compared to palm oil and a fat mixture rich in 18:2n−6, a fat mixture rich in 18:3n−3, but not fats rich in 18:3n−6, significantly decreased 3‐hydroxyacyl‐CoA dehydrogenase activity. Compared to palm oil and a fat mixture rich in 18:2n−6, borage oil profoundly decreased mitochondrial acyl‐CoA dehydrogenase activity, but a fat mixture rich in 18:3n−3 increased it. 2,4‐Dienoyl‐CoA reductase activity was significantly lower in rats fed palm oil than in other groups. Compared to other fats, borage oil significantly increased Δ3, Δ2‐enoyl‐CoA isomerase activity. Activity was also significantly higher in rats fed 18:2n−6 oil than in those fed palm oil. It was confirmed that both dietary 18:3n−6 and 18:3n−3 increased fatty acid oxidation activity in the liver. These two dietary octadecatrienoic acids differ considerably, however, in how they affect individual fatty acid oxidation enzymes.
Free fatty acid fractions from some vegetable oils exhibit reduced survival time‐shortening activity in stroke‐prone spontaneously hypertensive rats
Authors: Miyazaki Makoto , Huang Min‐Zhao , Takemura Naoya , Watanabe Shiro , Okuyama Harumi
Published: November 2006

Previously, we demonstrated that several vegetable oils that included low‐erucic rapeseed oil markedly shortened the survival time (by ∼40%) of stroke‐prone spontaneously hypertensive (SHRSP) rats as compared with perilla oil, soybean oil, and fish oil. We considered that a factor other than fatty acids is toxic to SHRSP rats, because the survival time‐shortening activity could not be accounted for by the fatty acid compositions of these oils. In fact, a free fatty acid (FFA) fraction derived from lipase‐treated rapeseed oil was found to be essentially devoid of such activity. A high‐oleate safflower oil/safflower oil/perilla oil mixture exhibited a survival time‐shortening activity comparable to that of rapeseed oil, but the activity of this mixed oil was also reduced by lipase treatment. A partially hydrogenated soybean oil shortened the survival time by ∼40%, but a FFA fraction derived from lipase‐treated partially hydrogenated soybean oil shortened it by 13% compared with soybean oil. Fatty acid compositions of the rapeseed oil and a FFA fraction derived from lipase‐treated rapeseed oil were similar, but those of hepatic phospholipids of rats fed the oil and FFA were slightly but significantly different. These results support the interpretation that the survival time‐shortening activity exhibited by some vegetable oils is due to minor components other than fatty acids, and that an active component(s) were produced in or contaminated soybean oil during the partial hydrogenation processes.
Docosahexaenoic acid does not affect aggression of normal volunteers under nonstressful conditions. A randomized, placebo‐controlled, double‐blind study
Authors: Hamazaki Tomohito , Sawazaki Shigeki , Nagao Yoko , Kuwamori Toyomi , Yazawa Kazunaga , Mizushima Yutaka , Kobayashi Masashi
Published: November 2006

We previously found that docosahexaenoic acid (DHA) intake prevents aggression enhancement at times of mental stress. In the present study we investigated changes in aggression under nonstressful conditions. Forty‐six students of two universities took either DHA‐rich fish oil capsules containing 1.5 g DHA (DHA group: 13 males and 9 females) or control oil capsules containing 97% soybean oil plus 3% of another fish oil (control group: 11 males and 13 females) for 3 mon in a double‐blind fashion. At the start and end of the study they took an aggression‐estimating test (P‐F Study) without a stressor component. DHA (5.9 to 8.5%, P<0.001) and eicosapentaenoic acid (0.7 to 1.5%, P<0.001) increased in red blood cell phospholipids in the DHA group, while linoleic acid increased slightly (8.3 to 9.1%, P<0.002) in the soybean oil control group. In the control group, measured aggression levels decreased from 34.8 to 29.4% (P<0.005), whereas they remained stable in the DHA group (33.5 to 33.8%). The intergroup differences (−5.4 vs. 0.3%) were marginally significant (P≤0.05). Aggression levels were stable in the DHA group whether there was stressor (as previously shown) or not. This effect of DHA appears to be interesting, considering the reported association between a low intake of n‐3 fatty acids and depression.
Protective effects of lemon flavonoids on oxidative stress in diabetic rats
Authors: Miyake Yoshiaki , Yamamoto Kanefumi , Tsujihara Nobuko , Osawa Toshihiko
Published: November 2006

The effects of lemon flavonoids, as crude flavonoids prepared from lemon juice, were investigated in diabetic rats. The oxidative stress of eriocitrin (eriodictyol 7‐O‐β‐rutinoside) and hesperidin (hesperetin 7‐O‐β‐rutinoside) on streptozotocin‐induced diabetic rats was investigated. Diabetic rats were given a diet which contained 0.2% crude flavonoids, 0.2% eriocitrin, and 0.2% hesperidin. After the 28‐d feeding period, the concentration of the thiobarbituric acid‐ reactive substance in the serum, liver, and kidney of diabetic rats administered crude flavonoids, eriocitrin, and hesperidin significantly decreased as compared with that of the diabetic group. The levels of 8‐hydroxydeoxyguanosine, which is exchanged from deoxyguanosine owing to oxidative stress, in the urine of diabetic rats administered eriocitrin and hesperidin significantly decreased as compared with that of the diabetic rat group. Crude flavonoids, eriocitrin, and hesperidin suppressed the oxidative stress in the diabetic rats. These results demonstrated that dietary lemon flavonoids of eriocitrin and hesperidin play a role as antioxidant in vivo.
Effects of α‐ and γ‐tocopherols on the autooxidation of purified sunflower triacylglycerols
Authors: Fuster Maria Dolores , Lampi Anna‐Maija , Hopia Anu , Kamal‐Eldin Afaf
Published: November 2006

The antioxidant effects of α‐ and γ‐tocopherols were evaluated in a model system based on the autooxidation of purified sunflower oil (p‐SFO) triacylglycerols at 55°C for 7 d. Both tocopherols were found to cause more than 90% reduction in peroxide value when present at concentrations >20 ppm. α‐Tocopherol was a better antioxidant than γ‐tocopherol at concentrations ≤40 ppm but a worse antioxidant at concentrations >200 ppm. Neither α‐ nor γ‐tocopherol showed a prooxidant effect at concentrations as high as 2000 ppm. The amount of tocopherols consumed during the course of oxidation was positively correlated to the initial concentration of tocopherols, and the correlation was stronger for α‐ than for γ‐tocopherol. This correlation suggested that, besides reactions with peroxyl radicals, destruction of tocopherols may be attributed to unknown side reactions. Addition of FeSO4, as a prooxidant, caused a 12% increase in the peroxide value of p‐SFO in the absence of tocopherols. When tocopherols were added together with FeSO4, some increase in peroxide value was observed for samples containing 200, 600 or 1000 ppm of α‐ but not γ‐tocopherol. The addition of FeSO4, however, caused an increase in the amount of α‐ and γ‐tocopherols destroyed and led to stronger positive correlations between the amount of tocopherols destroyed during oxidation and initial concentration of tocopherols. No synergistic or antagonistic interaction was observed when α‐ and γ‐tocopherols were added together to autooxidizing p‐SFO.
Production of antiserum for sensitive enzyme‐linked immunosorbent assay of 3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropanoic acid by chemiluminescence
Authors: Tanaka Touichi , Ikebuchi Hideharu , Sawada Jun‐ichi , Tanaka Yoshiko
Published: November 2006

To obtain a specific antiserum for use in enzymelinked immunosorbent assay (ELISA) of 3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropanoic acid (CMPF), we prepared a haptencarrier conjugate in which the CMPF hapten was linked to a carrier protein through the 5‐(1‐hydrazopropyl) group. The antisera raised against this antigen in guinea pigs had excellent specificity for CMPF, showing little cross‐reactivity with closely related compounds and no significant cross‐reactivities with other furan compounds. The results indicated that a specific antiserum to CMPF could be produced by an antigen whose CMPF moiety is linked to a carrier protein through a position remote from the inherent functional groups. A standard curve of CMPF by ELISA using a chemiluminescence system showed a high sensitivity and a linearity in the range of 5–100 ng/mL.
Microsequencing of bovine cerebrospinal fluid apolipoproteins: Identification of bovine apolipoprotein E
Authors: Puppione Donald L. , Fischer Wolfgang H. , Park Minkyu , Gazal Oladele S. , Williams Gary L.
Published: November 2006

In studies of bovine plasma lipoproteins, apolipoprotein E (apoE) was not found associated with α‐lipoproteins isolated over a broad range of densities. However, studies of cerebrospinal fluid (CSF) lipoproteins from other mammals have shown that apoE is a major apolipoprotein associated with high density lipoprotein, a fact that prompted us to determine if this were also the case in bovine CSF. CSF samples were obtained from animals with a surgically implanted catheter. Most analyzed samples were obtained from cows at various stages of the postpartum period; however, a few samples also were obtained at term or during pregnancy. Analyses of isolated ultracentrifugal fractions by polyacrylamide gel electrophoresis revealed the presence of two apo, with the expected molecular weights for apoE and apoA‐I. By using both matrix‐assisted laser desorption mass spectrometry and microsequencing techniques, we demonstrated that these apo are indeed apoE and apoA‐I.
Isolation and structure of glucosylceramides from the starfish Cosmasterias lurida
Authors: Maier Marta S. , Kuriss Anabel , Seldes Alicia M.
Published: November 2006

From the water‐insoluble lipid fraction of the methylene chloride/methanol extract of the starfish Cosmasterias lurida, two new glucosylceramides together with a known glucosylceramide, ophidiacerebroside E, were isolated by chromatographic procedures and characterized by spectroscopic (1H and 13C nuclear magnetic resonance, mass spectrometry) methods. The new compounds were identified as (2S, 3R, 4E, 8E, 10E)‐1‐(β‐d‐glucopyranosyloxy)‐3‐hydroxy‐2‐[(R)‐2‐hydroxyheptadecanoyl)amino]‐9‐methyl‐4,8,10‐octadecatriene (3) and (2S,3R,4E,8E,10E)‐1‐(β‐d‐glucopyranosyloxy)‐3‐hydroxy‐2‐[(R)‐2‐hydroxyoctadecanoyl)amino]‐9‐methyl‐4,8,10‐octadecatriene (4).
Replacement of partially hydrogenated soybean oil by palm oil in margarine without unfavorable effects on serum lipoproteins
Authors: Müller Hanne , Jordal Odd , Kierulf Peter , Kirkhus Bente , Pedersen Jan I.
Published: November 2006

We have compared the effects of three different margarines, one based on palm oil (PALM‐margarine), one based on partially hydrogenated soybean oil (TRANS‐margarine) and one with a high content of polyunsaturated fatty acids (PUFA‐margarine), on serum lipids in 27 young women. The main purpose of the study was to test if replacement of trans fatty acids in margarine by palmitic acid results in unfavorable effects on serum lipids. The sum of saturated fatty acids (12∶0, 14∶0, 16∶0) was 36.3% of total fatty acids in the PALM‐diet, the same as the sum of saturated (12∶0, 14∶0, 16∶0) (12.5%) and trans (23.1%) fatty acids in the TRANS‐diet. This sum was 20.7% in the PUFA‐diet. The content of oleic acid was 37.9, 35.2, and 38.6%, respectively, in the three diets, whereas linoleic acid amounted to 16, 13.5, and 27.3%, respectively. Total fat provided 30–31% and the test margarines 26% of total energy in all three diets. The subjects consumed each of the diets for 17 d in a Latin‐square crossover design. There were no significant differences in total cholesterol, low density lipoprotein (LDL)‐cholesterol and apolipoprotein B (apoB) between the TRANS‐and the PALM‐diets. High density lipoprotein (HDL)‐cholesterol and apoA‐I were significantly higher on the PALM‐diet compared to the TRANS‐diet whereas the ratio of LDL‐cholesterol to HDL‐cholesterol was lower, although not significantly (P=0.077) on the PALM‐diet. Total cholesterol, LDL‐cholesterol, and apoB were significantly lower on the PUFA‐diet compared to the two other diets. HDL‐cholesterol was not different on the PALM‐and the PUFA‐diets but it was significantly lower on the TRANS‐diet compared to the PUFA diet. Compared to the PUFA‐diet the ratio of LDL‐to HDL‐cholesterol was higher on both the PALM‐ and the TRANS‐diets whereas apoA‐I was not different. Triglycerides and lipoprotein (a) were not significantly different among the three diets. We concluded that nutritionally, palmitic acid from palm oil may be a reasonable alternative to trans fatty acids from partially hydrogenated soybean oil in margarine if the aim is to avoid trans fatty acids. A palm oil‐based margarine is, however, less favorable than one based on a more polyunsaturated vegetable oil.
Effects of long‐term feeding of marine oils with different positional distribution of eicosapentaenoic and docosahexaenoic acids on lipid metabolism, eicosanoid production, and platelet aggregation in hypercholesterolemic rats
Authors: Ikeda Ikuo , Yoshida Hiroko , Tomooka Miyuki , Yosef Adan , Imaizumi Katsumi , Tsuji Hiroaki , Seto Akira
Published: November 2006

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were distributed mainly in the sn‐1,3 positions of seal oil triglyceride and in the sn‐2 position of squid oil triglyceride. Seal oil‐rich or squid oil‐rich fats having constant saturated/monounsaturated/polyunsaturated fatty acid (PUFA) and n−6/n−3 PUFA ratios were fed to exogenously hypercholesterolemic rats for 160 d. The control fat contained linoleic acid as the sole PUFA. Before starting the experimental diets, rats were orally treated with high doses of vitamin D for 4 d to accelerate atherogenesis. The percentage of arachidonic acid in phosphatidylcholine and phosphatidylethanolamine of liver, platelets, and aorta was lower in the marine oil groups than in the control group, seal oil being more effective than squid oil. Maximal platelet aggregation induced by collagen was significantly lower both marine oil groups. Platelet thromboxane (TX) A2 production induced by collagen or thrombin was markedly reduced by feeding seal or squid oils, the reduction being more pronounced in the seal oil than in the squid oil group. Aortic prostacyclin (PGI2) production was the same among the three groups. The ratio of the productions of aortic PGI2 and platelet TXA2 was significantly higher in the seal oil than in the control group. Although there was no difference in intimal thickness among the three groups, the aortic cholesterol content was significantly lower in the marine oil groups than in the control group. These results showed that the main effects in rats of the different intramolecular distributions of EPA and DHA in dietary fats were on arachidonic acid content in tissue phospholipids and on platelet TXA2 production.
Dietary proteins modulate the effects of fish oil on triglyceridemia in the rat
Authors: Demonty Isabelle , Deshaies Yves , Jacques Hélène
Published: November 2006

Sprague‐Dawley rats were fed purified diets varying in both protein (20%) and lipid (11%) content for 28 d to verify the independent and interactive effects of dietary proteins and lipids on serum and hepatic lipids, and on tissue lipoprotein lipase (LPL) activity in both fasted and postprandial states. These diets consisted of either casein‐menhaden oil, casein‐coconut oil, soy protein‐menhaden oil (SPMO), soy protein‐coconut oil, cod protein‐menhaden oil, or cod protein‐coconut oil. A randomized 3×2 factorial design was used. A significant protein‐lipid interaction was seen on serum triglyceride levels: menhaden oil, compared with coconut oil, induced a decrease in serum triglyceride levels when combined with soy protein but not when combined with cod protein and casein. The lower serum triglyceride concentrations observed in the SPMO‐fed rats could be the result of decreased hepatic triglycerides when soy protein was compared with casein and when menhaden oil was compared with coconut oil. Total LPL activity in the heart was higher in menhaden oil‐fed rats than in coconut oil‐fed rats in the postprandial state. The higher LPL activity in the heart could, however, explain only 10% of the reduction of serum triglycerides, contributing slightly to the lowering effects of SPMO diet on serum triglycerides. Therefore, the present results indicate that dietary proteins can modulate the effects of fish oil on triglyceridemia in the rat, and that could be mainly related to specific alterations in hepatic lipid concentrations.
Carnitine palmitoyltransferase I, carnitine palmitoyltransferase II, and Acyl‐CoA oxidase activities in atlantic salmon (Salmo salar)
Authors: Frøyland Livar , Madsen Lise , Eckhoff Karen M. , Lie Øyvind , Berge Rolf K.
Published: November 2006

Salmon farmers are currently using high‐energy feeds containing up to 35% fat; the fish's capability of fully utilizing these high‐energy feeds has received little attention. Carnitine is an essential component in the process of mitochondrial fatty acid oxidation and, with the cooperation of two carnitine palmitoyltransferases (CPT‐I and CPT‐II) and a carnitine acylcarnitine transporter across the inner mitochondrial membrane, acts as a carrier for acyl groups into the mitochondrial matrix where β‐oxidation occurs. However, no reports are available differentiating between CPT‐I and CPT‐II activities in fish. In order to investigate the potential for fatty acid catabolism, the activities of key enzymes involved in fatty acid oxidation were determined in different tissues from farmed Atlantic salmon (Salmo salar), i.e., acyl‐CoA oxidase (ACO) and CPT‐I and CPT‐II. Malonyl‐CoA was a potent inhibitor of CPT‐I activity not only in red muscle but also in liver, white muscle, and heart. By expressing the enzyme activities per wet tissue, the CPT‐I activity of white muscle equaled that of the red muscle, both being>> liver. CPT‐II dominated in red muscle whereas the liver and white muscle activities were comparable. ACO activity was high in the liver regardless of how the data were calculated. Based on the CPT‐II activity and total palmitoyl‐l‐carnitine oxidation in white muscle, the white muscle might have a profound role in the overall fatty acid oxidation capacity in fish.
Phospholipid composition of the granular amebocyte from the horseshoe crab, Limulus polyphemus
Authors: MacPherson Jennifer C. , Pavlovich James G. , Jacobs Robert S.
Published: November 2006

The phospholipid composition was determined for the amebocyte of the primitive arthropod Limulus polyphemus. The total fatty acid composition of the cells' lipids was analyzed by gas chromatography/mass spectrometry (GC/MS) of fatty acid methyl esters (FAME). The FAME analysis revealed high levels of 20‐carbon polyunsaturated fatty acids (PUFA), especially arachidonic (20∶4n‐6) and eicosapentaenoic (20∶5n‐3) acids. Almost 20% of the total lipid profile was comprised of dimethyl acetals of 16‐ to 20‐carbon chain lengths, indicative of plasmalogens in the phospholipid pool. Phospholipids, analyzed by high‐pressure liquid chromatography, included phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI), sphingomyelin (SPH), and cardiolipin (CL). PE and PC levels predominated at 42.2 and 36.3%, respectively. Smaller amounts of PS (9.0%) and PI (6.2%) were present, as well as low levels of SPH (4.6%), CL (1.6%), and trace amounts of lysophosphatidylcholine. The major phospholipid species, PE, PC, PS and PI, were collected and their molecular species were examined by electrospray‐ionization mass spectrometry. The molecular species within the phospholipid classes reflected the high levels of PUFA seen in the total lipid profile. PI was mainly composed of 18∶0a/20∶4. Over half of the PS consisted of 18∶0a/18∶1 and 18∶0a/20∶4. The major PE species were 20∶1p/20∶5, 20∶1p/20∶4, 18∶0p/20∶5, and 18∶0p/20∶4. PC had the largest distribution of molecular species, and its most abundant species were 16∶0e/20∶5, 16∶0e/20∶4, and 16∶0p/20∶4. The presence of 16∶0e/20∶4 is the first documentation of a specific precursor to platelet‐activating factor in an invertebrate hemocyte. Note: at the sn‐1 position: [a=1=O‐acyl, e=1‐O‐alkylether, and p=1‐O‐alk‐1′‐enyl (plasmalogen)].
Involvement of phospholipids in apolipoprotein B modification during low density lipoprotein oxidation
Authors: Karakatsani Angeliki I. , Liapikos Theodoros A. , Troganis Anastasios N. , Tsoukatos Demokritos C.
Published: November 2006

An increased amount of phospholipids remained attached on delipidated apolipoprotein B originated from oxidized low density lipoprotein (LDL). 31P nuclear magnetic resonance analysis of such apolipoprotein showed an organic phosphorus peak at −0.55 ppm, which suggests the formation of adducts (most probably Schiff bases) of oxidized phospholipids with apolipoprotein B. The above reaction occurs in parallel with the hydrolysis of oxidized phospholipids, catalyzed by the LDL‐attached platelet‐activating factor acetylhydrolase, and may contribute to the proatherogenic effect of oxidatively modified low density lipoprotein.
Vitamin E reduces cholesterol esterification and uptake of acetylated low density lipoprotein in macrophages
Authors: Shige Hideki , Ishikawa Toshitsugu , Suzukawa Michio , Nishiwaki Masato , Yamashita Takeshi , Nakajima Kei , Ito Toshimitsu , Higashi Kenji , Ayaori Makoto , Yonemura Atsushi , Nestel Paul , Nakamura Haruo
Published: November 2006

The effects of vitamin E on cholesteryl ester (CE) metabolism in 1774 cells were examined. Pretreatment of 1774 cells with vitamin E at concentrations above 50 μM significantly decreased acetylated low density lipoprotein (LDL)‐induced incorporation of [14C]oleate into CF in cells in a dose‐dependent manner. This was partly due to vitamin E Also significantly inhibiting the uptake of [3H]CE‐labeled acetylated LDL by 1774 cells. A trend existed toward suppression of acyl‐CoA:cholesterol acyltransferase (ACAT) activity in the cell lysate at high vitamin E concentration, but there was no effect on hydrolysis of CE. These data indicate that vitamin E reduces the uptake of modified LDL and suppresses ACAT activity, resulting in less cholesterol esterification in macrophages; a novel mechanism underlying the antiatherogenic properties of vitamin E.
Regiospecific analysis of fractions of bovine milk fat triacylglycerols with the same partition number
Authors: Angers Paul , Tousignant Édith , Boudreau Armand , Arul Joseph
Published: November 2006

Bovine milk fat was fractionated using preparative reversed‐phase high‐performance liquid chromatography. The conditions consisted of two successive linear gradients of acetonitrile and tert‐butylmethylether, followed by a final isocratic mixture of the two eluants, leading to triacylglycerols grouped by their partition number (PN). Fractions corresponding to partition numbers 32 to 50 were isolated and analyzed for fatty acid distribution between sn‐1,3 and sn‐2 positions by Grignard degradation. Results showed that the fatty acid distribution in milk fat triacylglycerols is nonrandom. The distribution of short‐chain fatty acids, stearic (predominantly at sn‐1,3 position) and palmitic (predominantly sn‐2 position), did not change with triacylglycerol size. Medium‐chain fatty acids were predominantly located at sn‐2 position, but their proportion at this position decreased with triacylglycerol size. Oleic acid distribution was also size‐dependent in that it was located in high proportions at sn‐2 position in smaller triacylglycerols and vice versa. Results also showed that the sn‐2 position was more unsaturated than sn‐1,3 position in the PN range from 32 to 40, but it was more saturated in triacylglycerols with higher PN.
Calcium‐independent phospholipase A2 in isolated rabbit ventricular myocytes
Authors: McHowat Jane , Creer Michael H.
Published: November 2006

We characterized phospholipase A2 (PLA2) activity in isolated rabbit ventricular myocytes with respect to subcellular distribution, substrate specificity, and Ca2+ dependency. Membrane‐associated PLA2 was found to be an order of magnitude greater than cytosolic PLA2. Ventricular myocyte PLA2 activity was enhanced following protease‐activated receptor stimulation with thrombin and was found to be largely Ca2+‐independent and selective for phospholipid substrates containing arachidonic acid at the sn‐2 position. Immunoblot analysis using an antibody to cytosolic Ca2+‐independent PLA2 from Chinese hamster ovary cells recognized a membrane‐associated protein with a molecular mass of approximately 80 kDa; however, differences in pH optima, response to inhibitors, and substrate selectivity of membrane‐associated and cytosolic PLA2 activity suggest the presence of multiple Ca2+‐independent PLA2. Pretreatment with bromoenol lactone, a specific inhibitor of Ca2+‐independent PLA2, significantly attenuated membrane‐associated and cytosolic PLA2 in unstimulated and thrombin‐stimulated myocytes. Pretreatment with methyl arachidonyl fluorophosphonate, mepacrine, or dibucaine had no significant effect on PLA2 activity under all conditions tested. Ventricular myocyte PLA2 activity was significantly inhibited by ATP, GTP, and their nonhydrolyzable analogs and was regulated by protein kinase C activity. These studies demonstrate the presence of one or more unique membrane‐associated Ca2+‐independent PLA2 in isolated ventricular myocytes that exhibit a preference for phospholipids with arachidonate at the sn‐2 position and that are activated by thrombin stimulation.
In vivo studies of the biosynthesis of vernolic acid in the seed of Vernonia galamensis
Authors: Liu Linsen , Hammond Earl G. , Nikolau Basil J.
Published: November 2006

In vivo radiotracer experiments using [1‐14C]acetate as the precursor were conducted to investigate the biosynthesis of vernolic acid (12, 13‐epoxy‐cis‐9‐octadecenoic acid) in the seeds of Vernonia galamensis. The acetate precursor radioactively labeled vernolate in phosphatidylcholine (PC), diacylglycerol, and triacylglycerol. Time‐course kinetics of the incorporation of the radioactive tracer indicated that vernolate is synthesized while the acyl moiety is esterified to PC. Pulsechase experiments provided additional supporting evidence that vernolate is synthesized while esterified to PC. These results are consistent with the hypothesis that linoleoyl PC is the precursor of vernoleoyl‐PC. Subsequently, vernolate is quickly moved from the PC pool to the triacylglycerol pool, where it accumulates.
Lysophosphatidylcholine acyltransferase activity in Saccharomyces cerevisiae: Regulation by a high‐affinity Zn2+ binding site
Authors: Richard Martin G. , McMaster Christopher R.
Published: November 2006

Saccharomyces cerevisiae cells were demonstrated to contain lysophosphatidylcholine (lysoPtdCho) acyltransferase (E.C. 2.3.1.23) activity. The enzyme displayed Km(app) of 69 μM for lysoPtdCho and 152 μM for oleoyl CoA. Enzyme activity was not affected by the addition of 1 mM Mg2+, Mn2+, Ca2−, or 200 mM EDTA. However, Zn2+ inhibited lysoPtdCho acyltransferase activity to 33% control values at 0.1 mM and to 7% at 1.0 mM Zn2+. To further explore the possibility that lysoPtdCho acyltransferase may contain a high‐affinity Zn2+ binding site, we tested the strong Zn2+ chelator o‐phenanthroline for its ability to inhibit enzyme activity. LysoptdCho acyltransferase activity was inhibited to 18 and 27%, respectively, those of control values in the presence of 2 and 1 mM o‐phenanthroline, implying that a high‐affinity Zn2+ binding site exists in lysoPtdCho acyltransferase or in an accessory protein that is essential for protein stability and/or activity. Saccharomyces cerevisiae lysoPtdCho acyltransferase activity displayed a broad lysoPtdCho fatty acyl chain substrate specificity utilizing lysoPtdCho molecules ranging in length from C10−C20 (the entire range tested). In addition, the enzyme was capable of using the ether‐linked analog of lysoPtdCho, 1‐O‐alkyl‐2‐hydroxy‐sn‐3‐glycerophosphocholine, as a substrate. The ability of S. cerevisiae to incorporate radiolabeled 1‐O‐alkyl‐2‐hydroxy‐sn‐3‐glycerophosphocholine into phosphatidylcholine in vitro was exploited to demonstrate a direct precursor‐product relationship between lysoPtdCho molecules and their incorportation into phosphatidylcholine in vivo. Identical labeling results were obtained in S. cerevisiae cells disrupted for their major transacylase activity, PLB1, demonstrating that the incorporation of lysolipid was via acyltransferase, and not transacylase, activity.
Dietary effects of conjugated octadecatrienoic fatty acid (9 cis, 11 trans, 13 trans) levels on blood lipids and nonenzymatic in vitro lipid peroxidation in rats
Authors: Dhar P. , Ghosh S. , Bhattacharyya D. K.
Published: November 2006

The present study examined the antioxidant activity of conjugated octadecatrienoic fatty acid (9 cis, 11 trans, 13 trans‐18∶3), α‐eleostearic acid, of karela seed (Momordica charantia), fed to rats for 4 wk. The growth pattern of rats and the effect on plasma cholesterol and high density lipoprotein (HDL) cholesterol and peroxidation of plasma lipid, lipoprotein, eryhrocyte membrane, and liver lipid were measured. Rats were raised on diets containing sunflower oil mixed with three different levels of conjugated trienoic fatty acid (9c,11t,13t‐18∶3) 0.5,2, and 10% by weight; the control group was raised with sunflower oil as dietary oil as the source of linoleic acid (9c,12c‐18∶2). The growth pattern of the three experimental groups of rats showed no significant difference compared to the control group of rats, but the group with 10% 9c,11t,13t‐18∶3 had slightly higher body weight than the control group of rats. Concentrations of total cholesterol, HDL‐cholesterol, and non‐HDL‐cholesterol in plasma were similar in all four groups. Plasma lipid peroxidation was significantly lower in the case of 0.5% 9c,11t,13t‐18∶3 group than the control group and the 2 and 10% 9c,11t,13t‐18∶3 dietary groups as well. Lipoprotein oxidation susceptibility test with 0.5,2 and 10% 9c,11t,13t‐18∶3 dietary groups was significantly less susceptible to lipoprotein peroxidation when compared with sunflower oil dietary group, and the dietary group with 0.5% 9c,11t,13t‐18∶3 showed least susceptibility. There was significant lowering in erythrocyte ghost membrane lipid peroxidation in the 0.5,2, and 10% 9c,11t,13t‐18∶3 dietary groups compared to the sunflower oil groups. Nonenzymatic liver tissue lipid peroxidation was significantly lower in the group of rats raised on 0.5% 9c,11t,13t‐18∶3, but the groups on 2 and 10% 9c,11t,13t‐18∶3 acid did not show any significant difference compared with the control group of rats.
Effects of dietary polyunsaturated fatty acids on neuronal function
Authors: Fernstrom John D.
Published: November 2006

Diets deficient in linoleic acid (18∶2n−6), or that have unusual ratios of linoleic acid to α‐linolenic acid (18∶3n−3) induce changes in the polyunsaturated fatty acid (PUFA) composition of neuronal and glial membranes. Such changes have been linked to alterations in retina and brain function. These functional effects are presumed to follow from the biochemical consequences of modifying membrane PUFA content; known effects include modifications in membrane fludity, in the activities of membrane‐associated, functional proteins (transporters, receptors, enzymes), and in the production of important signaling molecules from oxygenated linoleic and α‐linolenic acid derivatives. However, despite the demonstration that central nervous system function changes when dietary PUFA intake is altered, and that in general, membrane PUFA content influences membrane functions, little work has focused specifically on brain and retina to reveal the underlying biochemical bases for such effects. This review examines this issue, looking at known effects of dietary PUFA on neurons in both the central and peripheral nervous systems, and attempts to identify some approaches that might promote productive investigation into the underlying mechanisms relating changes in dietary PUFA intake to alterations in neuronal and overall nervous system functioning.
Statistical considerations in infant nutrition trials
Authors: Gore Sheila M.
Published: November 2006

Infant nutrition trials usually require developmental follow‐up, often to 18 mon, and sometimes beyond reading ability at age 7 yr. They are therefore logistically complex and costly, and should be conducted to a high statistical standard. With examples, we focus on: good practice in nutrition trials and the goal of a common protocol; how to set plausible trial targets and to work out trial size accordingly; statistical observations on assessing visual maturation; and methods of randomization, including the method known as minimization, which can be adapted to select more appropriately a comparison cohort of breast‐fed infants. We end with discussion of analysis and reporting standards, including the give‐aways (or tell‐tale signs) to be on the look out for. A Cochrane Collaboration for systematic review of randomized trials of infant nutrition is proposed.
Biological effects and safety issues related to long‐chain polyunsaturated fatty acids in infants
Authors: Heird William C.
Published: November 2006

The purpose of this workshop at the American Oil Chemists’ Society Symposium, “PUFA in Infant Nutrition: Consensus and Controversies”, was to enumerate the safety issues raised by the prospect of supplementing infant formulas with long‐chain polyunsaturated fatty acids (LC‐PUFA), to evaluate the evidence that these concerns are problematical, or theoretically problematical, and to identify the safety issues most in need of resolution. This was approached by reviewing briefly the known biological effects of LC‐PUFA and how these effects might give rise to concerns about safety of LC‐PUFA as components of infant formulas. Some of these issues were then discussed in more detail by invited participants, all of whom had submitted abstracts concerning the issue discussed. The pertinent aspects of all issues discussed during the workshop are summarized. In addition, since the symposium was held over 2 yr ago, an addendum summarizing additional data reported since the symposium that either support or refute issues discussed during the workshop also is included.
Recent advances in brain cholesterol dynamics: Transport, domains, and Alzheimer's disease
Authors: Wood W. Gibson , Schroeder Friedhelm , Avdulov Nicolai A. , Chochina Svetlana V. , Igbavboa Urule
Published: November 2006

Major advances in understanding cholesterol dynamics and the role that cholesterol plays in vascular disease have recently been made. The brain is an organ that is highly enriched in cholesterol, but progress toward understanding brain cholesterol dynamics has been relatively limited. This review examines recent contributions to the understanding of brain cholesterol dynamics, focusing on extracellular and intracellular lipid carrier proteins, membrane cholesterol domains, and emerging evidence linking an association between cholesterol dynamics and Alzheimer's disease.
Evidence that the trans‐10,cis‐12 isomer of conjugated linoleic acid induces body composition changes in mice
Authors: Park Yeonhwa , Storkson Jayne M. , Albright Karen J. , Liu Wei , Pariza Michael W.
Published: November 2006

We investigated the effects of conjugated linoleic acid (CLA) preparations, which were enriched for the cis‐9,trans‐11 CLA isomer or the trans‐10,cis‐12 CLA isomer, on body composition in mice. Body composition changes (reduced body fat, enhanced body water, enhanced body protein, and enhanced body ash) were associated with feeding the trans‐10,cis‐12 CLA isomer. In cultured 3T3‐L1 adipocytes, the trans‐10,cis‐12 isomer reduced lipoprotein lipase activity, intracellular triacylglycerol and glycerol, and enhanced glycerol release into the medium. By contrast, the cis‐9,trans‐11 and trans‐9,trans‐11 CLA isomers did not affect these biochemical activities. We conclude that CLA‐associated body composition change results from feeding the trans‐10,cis‐12 isomer.