bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protective effects of lemon flavonoids on oxidative stress in diabetic rats
Authors: Miyake Yoshiaki , Yamamoto Kanefumi , Tsujihara Nobuko , Osawa Toshihiko 
Published: November 2006

AbstractThe 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

AbstractThe 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

AbstractTo 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

AbstractIn 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

AbstractFrom 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

AbstractWe 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

AbstractEicosapentaenoic 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

AbstractSprague‐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

AbstractSalmon 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

AbstractThe 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

AbstractAn 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

AbstractThe 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

AbstractBovine 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

AbstractWe 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

AbstractIn 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.