bluuebunny/crossref_metadata_2025 huggingface dataset:
Steryl esters in the elaioplasts of the tapetum in developing Brassica anthers and their recovery on the pollen surface
Authors: Wu Sherry S. H. , Moreau Robert A. , Whitaker Bruce D. , Huang Anthony H. C.
Published: November 2006

The tapetum cells in the developing anthers of Brassica napus contained abundant elaioplasts, which had few thylakoid membranes but were packed with globuli of neutral esters. Of the neutral esters, the major ester group possessed mainly 24‐methylenecholesterol, 31‐norcycloartenol, 24‐dehydropollinastanol, and pollinastanol esterified to 18∶3 and other unsaturated and saturated fatty‐acyl moieties. The minor ester group had a dominant component tentatively identified as 12‐dehydrolupeol esterified to mostly 18∶0, 16∶0, and 20∶0 fatty‐acyl moieties. The elaioplasts also contained a high proportion (16% w/w of total lipids) of monogalactosyldiacylglycerols (MGDG). This is the first report of plastids having steryl esters as the predominant lipids. We propose that the globuli contain steryl esters and are stabilized by surface MGDG and structural proteins. The tapetosomes, the other abundant lipid‐containing organelles in the tapetum, possessed tricylglycerols (TAG) as the predominant lipids. At a late stage of anther development, the minor group of neutral esters and MGDG of the elaioplasts, as well as the TAG of the tapetosomes, were degraded. Steryl esters similar to those of the elaioplasts were recovered from the pollen surface and were the major lipids of the pollen coat. The pollen coat steryl esters and proteins could be extracted with moderately polar or nonpolar solvents. These proteins, which were mostly fragments of oleosins derived from the tapetosomes, had a high proportion of lysine (13 mol %). The possible functions of the steryl esters and the proteins on the pollen surface are discussed.
Occurrence of γ‐linolenic acid in compositae: A study of Youngia tenuicaulis seed oil
Authors: Tsevegsüren Nanzad , Aitzetmüller Kurt , Vosmann Klaus
Published: November 2006

Seeds of Youngia tenuicaulis and other species from the plant family Compositae (Asteraceae) were studied for their oil content and fatty acid composition. The seed oil of Y. tenuicaulis growing in Mongolia was found to contain 5.6% γ‐linolenic acid (18∶3Δ6cis,9cis,12cis) in addition to common fatty acids. The oil was analyzed using chromatographic [capillary gas‐liquid chromatography (GLC), thin‐layer chromatography] and spectroscopic (infrared, gas chromatography‐mass spectrometry) techniques. Seed oil fatty acids of Saussurea amara (containing γ‐linolenic acid) and of Arctium minus (containing 18∶3Δ3trans,9cis,12cis), as well as Δ5cis‐ and Δ5trans‐18∶3 were used as GLC reference substances. The evolution in this plant family of a large number of different 18∶3 acids as well as the corresponding evolution of unusual desaturases should be investigated. On the other hand, the Δ6cis‐desaturase required for the biosynthesis of γ‐linolenic acid may have evolved independently several times in unrelated families of the plant kingdom.
High‐fat dairy product consumption increases Δ9c’ 11t−18∶2 (rumenic acid) and total lipid concentrations of human milk
Authors: Park Yongsoon , McGuire Michelle K. , Behr Rebecca , McGuire Mark A. , Evans Marc A. , Shultz Terry D.
Published: November 2006

Conjugated octadecadienoic acids (18∶2’ conjugated linoleic acids) have been shown to be anticarcinogenic and may influence growth and nutrient partitioning. The Δ9c’ 11t−18∶2 isomer (rumenic acid’ RA) is most common in both food sources and human tissues. To determine if maternal diet can influence milk RA concentration’ breastfeeding women (n=16) were enrolled in a 3‐wk crossover study. Women initially consumed minimal amounts of food containing RA during week 1’ then were assigned randomly to consume diets rich in high‐fat dairy foods (and thus RA) during week 2 or 3. Milk was collected by complete breast expression twice during each experimental week. Current and chronic RA intakes were estimated by 3‐d dietary records and food frequency question‐naires’ respectively. Estimated chronic RA intakes ranged from 49 to 659 mg/d. Dietary RA intake was greater during the high compared to the low dairy period (291±75 vs. 15±24 mg/d’ respectively; P<0.0001). Milk contained more RA during the high than the low dairy period (13.5±0.1 vs. 8.2±0.4 μmol/g lipid’ respectively; P<0.0001). Milk lipid concentration was influenced by diet’ such that lipid concentration was greater during the high than the low dairy period (46.6±5.0 vs. 38.3±1.6 mg/g milk’ respectively; P<0.05). Additionally’ multiple regression analyses suggested that body mass index was the primary predictor of milk RA and lipid concentrations. In summary’ these data indicate that both lipid and RA concentrations of human milk can be influenced by diet.
Elevated plasma levels of F2α isoprostane in cystic fibrosis
Authors: Collins Clare E. , Quaggiotto Paul , Wood Lisa , O'Loughlin Edward V. , Henty Richard L. , Garg Manohar L.
Published: November 2006

Cystic fibrosis (CT) is associated with chronic lung infection’ inflammation’ and elevated indices of oxidative stress. Recently’ isoprostanes were shown to be a reliable in vivo marker of oxidant injury with 8‐iso‐PGF2α’ shown to cause airflow obstruction and plasma exudation in guinea pig lung. The present study was designed to examine the relationship between 8‐iso‐PGF2α levels’ plasma antioxidants’ and clinical status in CF. We hypothesized that plasma 8‐iso‐PGF2α levels would be higher in subjects with CT compared to healthy controls. Plasma 8‐iso‐PGF2α levels were prospectively measured in 22 subjects with CF and nine healthy controls using an 8‐isoprostane enzyme immunoassay kit along with plasma vitamins A’ E’ and β‐carotene. Plasma 8‐iso‐PGF2α levels were shown to be significantly elevated in the CE subjects compared to controls (319.6±52.6 vs. 145.0±21.0 pg/ml’ P=0.005). Plasma levels of antioxidants were significantly lower for the CF subjects compared to the controls (vitamin A’P<0.003; vitamin E’ P<0.001; and β‐carotene’ P<0.01). This study confirns significantly elevated lipid peroxidation in CF using 8‐iso‐PGF2α levels.
Lymphatic absorption of phytosterol oxides in rats
Authors: Grandgirard André , Sergiel Jean‐Pierre , Nour Mohammed , Demaison‐Meloche Joelle , Gihiès Christian
Published: November 2006

Two of the main classes of oxyphytosterols (7‐keto and epoxides) were synthesized from sitosterol and campesterol and given to mesenteric duct‐cannulated adult male rats. Lymph was collected during 24 h and was analyzed for oxysterols. The results showed that the lymphatic recovery of the phytosterol oxides was low: 4.7% of the given dose for epoxy derivatives and 1.5% for 7‐keto compounds. The campesterol oxides presented a better absorption than the sitosterol oxides. During the process of absorption’ the epoxyphytostanols were also partly transformed in campestanetriol and stigmastanetriol.
The incorporation of fatty acids of different chain length into liver and biliary lipids in the perfused rat liver
Authors: Rubin Moshe , Pakula Ronit , Gilat Tuvia , Tietz Alisa
Published: November 2006

In an attempt to correlate the incorporation of fatty acids (FA) of different chain length into liver and biliary lipids’ isolated rat livers were perfused for 2 h with Krebs‐Ringer bicarbonate containing 1% albumin and 10 μmol of [1‐14C]‐labeled FA: C2’ C8’ C10’ C12’ C16’ and C18∶1. One to 1.36 μmol of medium‐chain fatty acids (MCFA’ C8’ C10’ and C12) and 6.6 μmol of long‐chain FA (LCFA) were incorporated into liver lipids’ 40% of the latter into phosphatidylcholine (PC). 14C‐acetate (13 nmol) was incorporated into biliary cholesterol; 14C‐MCFA contributed only 3.2–5 nmol; LCFA did not lead to newly synthesized cholesterol. Newly synthesized liver PC (2.75 to 3.25%) and newly synthesized liver cholesterol (6.5 to 10%) were secreted into bile. The specific radioactivity of biliary PC after infusion of all‐saturated FA was 3.8–6.8 times higher than that of liver PC; for C18∶1 it was only 1.7‐fold. The specific radioactivity of biliary cholesterol’ as compared to liver cholesterol’ was 12 times higher for C2 and five times higher for MCFA. This indicates that a considerable proportion of the newly synthesized lipids was secreted into bile prior to significant mixing with preexisting liver PC and cholesterol pools. liver PC contained 8% of unchanged 14C−C12; while 14C−C10 was not detected. Biliary PC’ in contrast’ contained 18% of unchanged 14C−C12 and 3% 14C−C10. These results suggest that after prolonged infusion of medium‐chain triacylglycerols/longchain triacylglycerols to patients’ biliary PC may become enriched with MCFA. In addition’ the oxidation of these FA may provide C‐2 units which increase cholesterol synthesis.
The metabolism of native and randomized butterfat chylomicrons in the rat is similar
Authors: Hodge Jason , Li Duo , Redgrave Trevor G. , Sinclair Andrew J.
Published: November 2006

Reportedly’ randomly rearranging the position of fatty acids (FA) in butterfat triacylglycerol (TAG) by interesterification’ thereby lowering the proportion of saturated FA in the sn‐2 position’ reduces its hypercholesterolemic and hypertriglyceridemic properties when fed to humans. The aim of this work was to determine if these reductions in plasma cholesterol and TAG could be explained by an improved rate of clearance from the plasma of chylomicrons composed of randomized butterfat’ using a rat model. Acute chylomicron clearance studies demonstrated no differences in fractional clearance rates of cholesteryl esters and TAG from the plasma of rats infused with chylomicrons produced from gastric feeding of either native (NBF) or randomized (RBF) butterfat. Although there was a 14% decrease in the level of saturated FA occupying the sn‐2 position of TAG in RBF compared with NBF’ this difference became negligible (∼5%)’ following digestion of the fat and subsequent repackaging of TAG into chylomicrons. These observations suggest that the previously observed reduction in hypercholesterolemic properties of randomized butterfat in rat is unlikely to be explained by improved clearance of chylomicron TAG.
Cholesterol synthesis and degradation in normal rats fed a cholesterol‐free diet with excess cystine
Authors: Aoyama Yoritaka , Amano Nobuyuki , Yoshida Akira
Published: November 2006

Feeding a diet with excess cystine to rats resulted in hypercholesterolemia. To understand the mechanism of the hypercholesterolemia’ cholesterol synthesis and degradation’ bile acid content of bile’ and fecal steroids were determined. The in vivo incorporation of tritiated water into hepatic cholesterol’ and activity of hepatic 3‐hydroxy‐3‐methylglutaryl‐CoA reductase in rats fed a high‐cystine diet were significantly higher than those in rats fed a control diet. The activity of hepatic cholesterol 7α‐hydroxylase was similar between two groups. Little effect of cystine supplementation was found on fecal sterol excretion although there were some changes in biliary excretion of cholic acid derivatives. These results indicate that hypercholesterolemia caused by feeding of a high‐cystine diet may be due to the stimulation of hepatic cholesterol synthesis.
Cell proliferation’ differentiation’ and apoptosis are modified by n−3 polyunsaturated fatty acids in normal colonic mucosa
Authors: Calviello Gabriella , Palozza Paola , Maggiano Nicola , Piccioni Elisabetta , Franceschelli Piergiorgio , Frattucci Andrea , Di Nicuolo Fiorella , Bartoh Gianna Maria
Published: November 2006

Supplementation with low doses of eicosapentaenoic (EPA) or docosahexaenoic (DHA) acid was used here to investigate changes in epithelial proliferation’ differentiation’ and apoptosis in normal rat colonic mucosa. ACI/T rats received by oral administration low doses of purified EPA or DHA ethyl esters (1g/kg body weight) and colonic mucosa was analyzed for cell proliferation’ differentiation’ and apoptosis. n−3 Polyunsaturated fatty acid incorporation into membrane phospholipids was investigated as reflections of fatty acid metabolism. Both EPA and DHA suppressed colonocyle proliferation and increased the numbers of differentiating and apoptotic cells without modification of the crypt morphology and the number of cells per crypt columns. A significant incorporation of the supplemented fatty acids into total phospholipids was observed. This enrichment was accompanied by a decreased content in arachidonic acid. The observation that EPA and DHA do not alter crypt morphology although they modify cell turnover in normal colonic mucosa suggests a possible use of these fatty acids as dietary chemopreventive agents.
Enhancement of sterol synthesis by the monoterpene perillyl alcohol is unaffected by competitive 3‐hydroxy‐3‐methylglutaryl‐CoA reductase inhibition
Authors: Cerda sonia R. , Wilkinson John , Branch Steven K. , Broitman Selwyn A.
Published: November 2006

Monoterpenes such as limonene and perillyl alcohol (PA) are currently under investigation for their chemotherapeutic properties which have been tied to their ability to affect protein isoprenylation. Because PA affects the synthesis of isoprenoids’ such as ubiquinone’ and cholesterol is the end product of the synthetic pathway from which this isoprenoid pathway branches’ we investigated the effects of this compound upon cholesterol metabolism in the colonic adenocarcinoma cell line SW480. PA (1 mM) inhibited incorporation of 14C‐mevalonate into 21–26 kDa proteins by 25% in SW480 cells. Cholesterol (CH) biosynthesis was assessed by measuring the incorporation of 14C‐acetate and 14C‐mevalonate into 27‐carbon‐sterols. Cells treated with PA (1 mM) exhibited a fourfold increase in the incorporation of 14C‐acetate but not 14C‐mevalonate into cholesterol. Mevinolin (lovastatin)’ an inhibitor of 3‐hydroxy‐3‐methylglutaryl‐CoA (HMG‐CoA) reductase’ at 2 μM concentration’ inhibited CH synthesis from 14C‐acetate by 80%. Surprisingly’ concurrent addition of mevinolin and PA did not significantly alter the stimulatory effects of PA. As observed differences in 14C‐acetate and 14C‐mevalonate precursor labeling could indicate PA affects early pathway events’ the effects of this monoterpene on HMG‐CoA reductase activity were evaluated. Unexpectedly’ 1 mM PA did not stimulate activity of this enzyme. Consistent with its action as a reversibly bound inhibitor’ in washed microsomes’ 2 μM mevinolin pretreatment increased reductase protein expression causing a 12.7 (±2.4)‐fold compensatory HMG‐CoA reductase activity increase; concurrent treatment with 1 mM PA attenuated this to a 5.3 (±0.03)‐fold increase. Gas chromatographic analysis confirmed CH was the major lipid present in the measured thin‐layer chromatography spot. Since 14C‐acetate incorporation into free fatty acid and phospholipid pools was not significantly affected by PA treatment’ nonspecific changes in whole acetate pool sizes were not indicated. Because increases in endogenous CH synthesis should result in compensatory changes in exogenous sterol utilization’ the effects of PA upon low density lipoprotein (LDL) receptor activity were evaluated. Consistent with the observed increases in CH synthesis’ 1 mM PA decreased 125I‐LDL internalization to 50% of the fetal bovine serum control; concurrent addition of 2 μM mevinolin attenuated this effect to a reduction of 80% of the control value. Data suggest that in certain colonic tumor cells PA strongly affects cholesterol metabolism via a mechanism of action that is insensitive to the HMG‐CoA reductase inhibitor mevinolin.
The metabolism and distribution of sesame lignans (sesamin and episesamin) in rats
Authors: Umeda‐Sawada Rumi , Ogawa Megumi , Igarashi Osamu
Published: November 2006

In this study’ we examined the distribution and metabolism of refined sesame oil lignans (sesamin and episesamin) in rat. For 8 wk rats were fed the diet including 0.5% (w/w) sesame lignans (sesamin and episesamin) with 5% (w/w) corn oil or eicosapentaenoic acid (EPA)‐rich oil. The concentrations of sesamin and episesamin in rat liver after their administration for 8 wk were very low; both of them were less than 0.5 μg/g liver. These were observed in both oil groups although the fatty acid compositions of dietary oils were completely different. No significant difference existed in lymphatic absorption between sesamin and episesamin. To investigate the distribution of sesamin and episesamin in rats’ the concentrations of sesamin and episesamin were determined in tissues and serum within 24h after administration to rats. Sesamin and episesamin may be’ at first’ incorporated into the liver and then transported to the other tissues (lung’ heart’ kidney’ and brain). They are lost from the body within 24h after administration. There was no significant difference in lymphatic absorption between sesamin and episesamin’ but the amount of sesamin was significantly lower than that of episesamin in all tissues and serum. These results suggest that sesamin is absorbed in lymph the same as episesamin’ but that sesamin is subsequently metabolized faster by the liver.
Seasonal variation in the fatty acid composition and quality of sardine oil from sardinops sagax caeruleus of the gulf of California
Authors: Gámez‐Meza N. , Higuera‐Ciapara I. , Calderon de la Barca A. M. , Vázquez‐Moreno L. , Noriega‐Rodríguez J. , Angulo‐Guerrero O.
Published: November 2006

One of the few sources of long‐chain n‐3 polyun‐saturated fatty acids is fish oil’ but considerable variation may exist according to species and season. In this study’ the fatty acid profiles of sardine oils from Sardinops sagax caeruleus of the Gulf of California’ Mexico’ were evaluated in three seasonal catch periods. Oil quality was also evaluated by peroxide and free acid values. The most abundant fatty acids found in the oils were palmitic acid (19.3%)’ oleic acid (14.3%)’ eicosapentaenoic acid (EPA’ 20.4%)’ and docosahexaenoic acid (DHA’ 12.2%). There was no significant difference in the composition and quality among the six reduction plants where the samples were obtained. However’ a significant difference in the proportion of EPA and DHA in one of the catch seasons analyzed was observed.
Specific modifications of phosphatidylinositol and nonesterified fatty acid fractions in cultured porcine cardiomyocytes supplemented with n‐3 polyunsaturated fatty acids
Authors: Nair Sudheera S. D. , Leitch James , Garg Manohar L.
Published: November 2006

Mechanisms for the antiarrhythmic effect of n−3 polyunsaturated fatty acids (PUFA) are currently being investigated using isolated cardiac myocytes. It is still not known whether the incorporation of n−3 PUFA into membrane phospholipids is a prerequisite for its protective action or if n−3 PUFA exert antiarrhythmic effects in their nonesterified form as demonstrated by recent studies. Adult porcine cardiomyocytes were grown in media supplemented with arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). After 24 h, analysis of total lipids showed that the myocytes were enriched with the respective fatty acids compared to control cells. Large proportions of all three fatty acids supplemented (69% AA, 72% DHA, and 66% EPA) remained unesterified. Fatty acid analysis of total phospholipids (PL) revealed that the incorporation of EPA and DHA, though small, was significantly different (P<0.05) from that of the control cells. The PL fraction was further separated into phosphatidylinositol (Pl), phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine to study the pattern of incorporation of the fatty acids in these fractions. It became apparent that EPA and DHA were selectively incorporated into the Pl fraction. This study demonstrates that in adult porcine cardiomyocytes, the n−3 PUFA supplementation selectively modulates two important lipid fractions, nonesterified fatty acid and Pl, which were implicated in the mechanisms of prevention of cardiac arrhythmias.
Dose‐dependent inhibition of cell proliferation induced by lipid peroxidation products in rat hepatoma cells after enrichment with arachidonic acid
Authors: Muzio Giuliana , Salvo Raffaella A. , Trombetta Antonella , Autelli Riccardo , Maggiora Marina , Terreno Mario , Dianzani Mario U. , Canuto Rosa A.
Published: November 2006

Polyunsaturated fatty acids (PUFA) are important constituents of membrane phospholipids, whose levels are decreased in some tumor cells. This deficiency may cause alterations in signal transduction and an interruption of normal cellular events. The enrichment of tumor cells with PUFA may stimulate or inhibit tumor growth, probably depending on the type of PUFA and the cellular concentration of aldehydes derived from restored lipid peroxidation. We examined the effect of several doses of prooxidant on the growth of hepatoma cells with different aldehyde dehydrogenase activities, enriched with arachidonic acid. Two doses of prooxidant were sufficient to reduce growth of hepatoma cells with low aldehyde dehydrogenase activity, whereas three doses were necessary for those with high enzyme activity. In both cases, lipid peroxidation products blocked the cells in the S phase.
Ethanol‐extracted soy protein isolate results in elevation of serum cholesterol in exogenously hypercholesterolemic rats
Authors: Ni Weihua , Yoshida Susumu , Tsuda Yasuyuki , Nagao Koji , Sato Masao , Imaizumi Katsumi
Published: November 2006

Soy protein preparations were reported to have hypocholesterolemic actions in experimental animals and humans, while the active components and the mechanism by which this occurs are not clarified yet. The objective of this study is to address these issues by using exogenously hypercholesterolemic rats which are susceptible to dietary cholesterol. Two groups of five rats (male, 12‐wk‐old) were fed on AIN 93G‐based diet with soy protein isolate (SPI) or ethanol‐extracted SPI (EE‐SPI) for 2 wk. EE‐SPI was prepared by ethanol extraction to remove isoflavones and other components. Concentrations of serum and liver total cholesterol were lower in rats fed SPI than in those fed EE‐SPI. The abundances of mRNA for 7α‐hydroxylase and low density lipoprotein receptor in the liver were lower in EE‐SPI group than those in SPI group. These results suggest that the ethanol extract from SPI has a factor(s) to alleviate hypercholesterolemia by increasing the removal of cholesterol from serum through the receptor pathway and then from liver through enhancement of bile acid synthesis.
Absorption in rats of rapeseed, soybean, and sunflower oils before and following moderate heating
Authors: Porsgaard Trine , Zhang Hong , Nielsen Robert G. , Høy Carl‐Erik
Published: November 2006

Rapeseed, soybean, and sunflower oil were heated for 15 min in a 5‐mm oil layer in a pan at 180°C. The fatty acid composition was almost unaffected by heating, while the polymer content rose slightly and the tocopherol content decreased, except in soybean oil. The absorption of oils before and after heating was investigated in lymph‐cannulated rats. Oils were administered as emulsions through a gastrostomy tube and lymph was collected during the next 24 h. The highest accumulated lymphatic transport of total fatty acids was observed after administration of rapeseed oil, and the lowest after heated sunflower oil. The accumulated transport was similar for all unheated oils. The transport of fatty acids was significantly lower in rats receiving heated oil compared to those receiving the corresponding unheated oil. Small increases in polymers may have contributed to the decreased lymphatic transport of oil following heating, although this probably does not fully explain the effect. The absorption of sunflower oil was more affected by heating than the absorption of soybean or rapeseed oil. Furthermore, the largest decrease in total activity of tocopherols following heating was observed in sunflower oil. Overall, these results demonstrate that the absorption of vegetable oils is affected by moderate heating.
Fatty acid composition of brain glycerophospholipids in peroxisomal disorders
Authors: Martinez Manuela , Mougan Isabel
Published: November 2006

This paper shows for the first time the differential fatty acid composition of ethanolamine plasmalogens (EP) and phosphatidylethanolamine (PE) in the brains of 12 patients with disorders of peroxisomal biogenesis and compares the results to normal values for the age. Other important glycerophospholipids (GPL), such as phosphatidylserine (PS) and phosphatidylcholine (PC), are also included in this study. GPL were separated by two‐dimensional thin‐layer chromatography, and their fatty acid composition was determined by capillary column gas‐liquid chromatography. Total brain GPL were slightly decreased in peroxisomal disorders (27.98±2.95 μmol/g in the patients against 34.5±6.21 μmol/g in age‐matched controls, P=0.005), and the distribution of the different GPL classes was much altered. In confirmation of known data, EP were very much decreased (2.18±1.3 μmol/g in the patients against 6.9±2.3 μmol/g in controls) at the expense of PE, which was increased (8.58±2.17 μmol/g in the patients against 5.97±0.58 μmol/g in controls, P<0.005). PS and PC were both significantly decreased (P=0.0001 and P=0.037, respectively). The polyunsaturated fatty acid (PUFA) composition of all the GPL fractions was markedly abnormal. In absolute terms, docosahexaenoic acid (22∶6n−3) was drastically decreased in all GPL classes (always at the P<0.0001 level) while arachidonic acid (20∶4n−6) was increased in PE and PS (P<0.001 in both cases). In the alkenyl acyl form, EP, 22∶6n−3, and 20∶4n−6 were both very significantly decreased (P<0.0001), although the former was always the most affected. The myelin PUFA adrenic acid (22∶4n−6) was decreased in EP (P<0.0001) and slightly increased in PS (P<0.05). The changes found confirm that 22∶6n−3 deficiency is a predominant defect in the brain in peroxisomal disorders.
Recognition and quantitation of cis‐vaccenic and eicosenoic fatty acids in olive oils by 13C nuclear magnetic resonance spectroscopy
Authors: Scano P. , Casu M. , Lai A. , Saba G. , Dessi M. A. , Deiana M. , Corongiu F. P. , Bandino G.
Published: November 2006

The presence of 11‐cis monoenoic fatty acids was detected in olive oil samples by means of 13C nuclear magnetic resonance spectroscopy, and the positional isomery on the glycerol backbone was derived. The 11‐cis vaccenic and eicosenoic fatty acid resonances were recognized and the amounts of the fatty acids quantified. For comparison purposes, a quantitative analysis was also made by gas chromatography.
Olestra formulation and the gastrointestinal tract
Authors: Jandacek Ronald J. , Kester Jeffrey J. , Papa A. J. , Wehmeier Thomas J. , Lin Peter Y. T.
Published: November 2006

Olestra is a mixture of compounds comprising sucrose esterified with 6–8 long‐chain fatty acids. It is not hydrolyzed by pancreatic lipase and as a result is not absorbed from the small intestine. Olestra in general has physical properties similar to those of a triacylglycerol with the same fatty acid composition. Foods made with olestra are virtually identical in taste and texture to those made with typical triacylglycerols. Olestra consumption does not generate hydrolytic products in the small intestine and, therefore, does not generate some of the signals that alter motility in the gastrointestinal tract. A reduction in gastroesophageal reflux with olestra, in contrast to triacylglycerols, is consistent with a lack of effect on stomach emptying. Unlike triacylglycerols that are absorbed in the proximal small intestine, olestra is distributed throughout the small intestine during transit and passes into the colon. In the colon, olestra's effects depend on its physical properties. Liquid nondigestible lipids result in separation of oil from the fecal matrix. Olestra formulations made with specific fatty acid compositions, particularly those containing a solid sucrose polyester component including behenic acid, possess appropriate rheology to hinder separation of oil from the rest of the fecal matrix, thereby reducing gastrointestinal symptoms.
Effect of dietary docosahexaenoic acid on desaturation and uptake in vivo of isotope‐labeled oleic, linoleic, and linolenic acids by male subjects
Authors: Emken E. A. , Adlof R. O. , Duval S. M. , Nelson G. J.
Published: November 2006

The effect of dietary docosahexaenoic acid (22∶6n−3, DHA) on the metabolism of oleic, linoleic, and linolenic acids was investigated in male subjects (n=6) confined to a metabolic unit and fed diets containing 6.5 or <0.1 g/d of DHA for 90 d. At the end of the diet period, the subjects were fed a mixture of deuterated triglycerides containing 18∶1n−9[d6], 18∶2n−6[d2], and 18∶3n−3[d4]. Blood samples were drawn at 0, 2, 4, 6, 8, 12, 24, 48, and 72 h. Methyl esters of plasma total lipids, triglycerides, phospholipids, and cholesterol esters were analyzed by gas chromatography‐mass spectrometry. Chylomicron triglyceride results show that the deuterated fatty acids were equally well absorbed and diet did not influence absorption. Compared to the low‐DHA diet (LO‐DHA), clearance of the labeled fatty acids from chylomicron triglycerides was modestly higher for subjects fed the high DHA diet (HI‐DHA). DHA supplementation significantly reduced the concentrations of most n‐6[d2] and n‐3[d4] long‐chain fatty acid (LCFA) metabolites in plasma lipids. Accumulation of 20∶5n−3[d4] and 22∶6n−3[d4] was depressed by 76 and 88%, respectively. Accumulations of 20∶3n−6[d2] and 20∶4n−6[d2] were both decreased by 72%. No effect of diet was observed on acyltransferase selectivity or on uptake and clearance of 18∶1n−9[d6], 18∶2n−6[d2], and 18∶3n−3[d4]. The results indicate that accumulation of n−3 LCFA metabolites synthesized from 18∶3n−3 in typical U.S. diets would be reduced from about 120 to 30 mg/d by supplementation with 6.5 g/d of DHA. Accumulation of n−6 LCFA metabolites synthesized from 18∶2n−6 in U.S. diets is estimated to be reduced from about 800 to 180 mg/d. This decrease is two to three times the amount of n−6 LCFA in a typical U.S. diet. These results support the hypothesis that health benefits associated with DHA supplementation are the combined result of reduced accretion of n−6 LCFA metabolites and an increase in n−3 LCFA levels in tissue lipids.
Fatty acid analysis of blood serum, seminal plasma, and spermatozoa of normozoospermic vs. Asthernozoospermic males
Authors: Conquer Julie A. , Martin James B. , Tummon Ian , Watson Lynn , Tekpetey Francis
Published: November 2006

Docosahexaenoic acid (DHA; 22∶6n−3) is found in extremely high levels in human ejaculate with the majority occurring in the spermatozoa. However, the relative concentration of DHA and other fatty acids, in blood serum, seminal plasma, and spermatozoa of asthenozoospermic vs. normozoospermic individuals is not known. We analyzed the phospholipid fatty acid composition of blood serum, seminal plasma, and spermatozoa of normozoospermic men and asthenozoospermic men in order to determine if DHA levels, as well as the levels of other fatty acids, differed. The serum phospholipid DHA levels were similar in the two groups, suggesting similar intakes of dietary DHA. On the other hand, seminal plasma levels of DHA (3.0 vs. 3.7%) and total polyunsaturated fatty acids (PUFA) (11.8 vs. 13.5%) were significantly lower in asthenozoospermic vs. normozoospermic men, respectively, while 18∶1 (19.0 vs. 16.8%) and monounsaturated fatty acids (MUFA) (24.2 vs. 21.7%) were significantly higher in the asthenozoospermic vs. the normozoospermic men. Spermatozoa from asthenozoospermic men had higher levels of 18∶1, 20∶0, 22∶0, 22∶1, and 24∶0 than sperm from normozoospermic men, and lower levels of 18∶0 and DHA (8.2 vs. 13.8%). Furthermore, total MUFA (19.3 vs. 16.5%) was higher and total PUFA (19.0 vs. 24.0%), n−3 fatty acids (9.3 vs. 14.6%), and the ratio of n−3 to n−6 fatty acids (1.0 vs. 1.6) were lower in the asthenozoospermic men. Therefore, in asthenozoospermic individuals, lower levels of DHA in the seminal plasma, but not in the blood serum, mimic the decreased concentrations of DHA in the spermatozoa. This suggests that the lower concentrations of spermatozoon DHA in these individuals are due not to dietary differences but to some type of metabolic difference in the asthenozoopermic men.
Apolipoprotein B mRNA editing and apolipoprotein gene expression in the liver of hyperinsulinemic fatty zucker rats: Relationship to very low density lipoprotein composition
Authors: Elam Marshall B. , von Wronski Matthew A. , Cagen Lauren , Thorngate Fayanne , Kumar Poonam , Heimberg Murray , Wilcox Henry G.
Published: November 2006

We previously demonstrated increased apolipoprotein B (apoB) mRNA editing, elevated levels of mRNA for the catalytic component of the apoB mRNA editing complex, apobec‐1, and increased secretion of the product of the edited mRNA, apoB48, in very low density lipoproteins (VLDL) in primary cultures of Sprague‐Dawley rat hepatocytes following insulin treatment. In order to determine the effect of in vivo hyperinsulinemia on these processes, we determined apoB mRNA editing, apobec‐1 expression, hepatic expression of mRNA for apoB and other VLDL apoproteins, and the quantity and composition of plasma VLDL in the hyperinsulinemic fatty Zucker rat. Total apoB mRNA content of the livers of the fatty rats and lean littermates did not differ, however, edited apoB message coding for hepatic apo B48, and abundance of mRNA for the catalytic subunit of the apoB mRNA editing complex, apobec‐1, was increased by 1.7‐and 3.3‐fold, respectively, in fatty rats. ApoCIII mRNA abundance was increased in livers of fatty rats as well, but the abundance of hepatic apoE mRNA in the fatty animal was not different from that of the lean rat. Hepatic apoAI mRNA abundance was also increased in the fatty rats. Associated with increased apoB mRNA editing, was the 1.7‐fold increase in the fraction of apoB in plasma as apoB48 in fatty rats. VLDL‐triglyceride and‐apoB in plasma were 15‐and 3‐fold higher, respectively, in fatty Zucker rats compared to lean littermates, indicating both enrichment of VLDL with triglycerides and increased accumulation of VLDL particles. Increased hepatic expression of mRNA for apoCIII and apoAI was associated with increased content of apoC (and relative depletion of apoE) in VLDL of fatty rats, and plasma apoAI was increased in fatty Zucker rats, primarily in the HDL fraction. The current study provides further evidence that chronic exposure to high levels of insulin influences both the quantity of and lipid/apoprotein composition of VLDL in plasma. The increased apoC and decreased apoE (as well as increased triglyceride) content of VLDL in the fatty Zucker rat observed in the current study may affect VLDL clearance and therefore may be a factor in the observed accumulation of VLDL in the plasma of the fatty hyperinsulinemic Zucker rats.
Characterization of the ybdT gene product of Bacillus subtilis: Novel fatty acid β‐hydroxylating cytochrome P450
Authors: Matsunaga Isamu , Ueda Atsuo , Fujiwara Nagatoshi , Sumimoto Tatsuo , Ichihara Kosuke
Published: November 2006

We have characterized the gene encoding fatty acid α‐hydroxylase, a cytochrome P450 (P450) enzyme, from Sphingomonas paucimobilis. A database homology search indicated that the deduced amino acid sequence of this gene product was 44% identical to that of the ybdT gene product that is a 48 kDa protein of unknown function from Bacillus subtilis. In this study, we cloned the ybdT gene and characterized this gene product using a recombinant enzyme to clarify function of the ybdT gene product. The carbon monoxide difference spectrum of the recombinant enzyme showed the characteristic one of P450. In the presence of H2O2, the recombinant ybdT gene product hydroxylated myristic acid to produce β‐hydroxyristic acid and α‐hydroxymyristic acid which were determined by high‐performance liquid chromatography (HPLC) and gas chromatography‐mass spectrometry. The amount of these products increased with increasing reaction period and amount of H2O2 in the reaction mixture. The amount of β‐hydroxyl product was slightly higher than that of α‐hydroxyl product at all times during the reaction. However, no reaction products were detected at any time or at any concentration of H2O2 when heat‐inactivated enzyme was used. HPLC analysis with a chiral column showed that the β‐hydroxyl product was nearly enantiomerically pure R‐form. These results suggest that this P450 enzyme is involved in a novel biosynthesis of β‐hydroxy fatty acid.
Identification of acylated glycoglycerolipids from a cyanobacterium, Synechocystis sp., by tandem mass spectrometry
Authors: Kim Young Hwan , Choi Jong‐Soon , Hong Jongki , Yoo Jong Shin , Kim Myung Soo
Published: November 2006

Acylated glycoglycerolipids were identified in the total lipid extract from cyanobacerium Synechocystis sp. PCC 6803. These compounds have a palmitoyl group esterified to the hydroxyl group at the C‐6 position of the terminal glycosyl moiety of digalactosyl monoacylglycerol and digalactosyl diacylglycerol. Their structural elucidation was accomplished by tandem mass spectrometry coupled with fast atom bombardment ionization. Acylated digalactosyl monoacylglycerol has a structure of 1‐hydroxy‐2‐palmitoyl‐3‐O‐[(6‐O‐palmitoyl)‐α‐d‐galactopyranosyl‐(1→6)‐β‐d‐galactopyranosyl]‐sn‐glycerol. This compound has not been reported previously.
Δ5‐Olefinic acids in the seed lipids from four Ephedra species and their distribution between the α and β positions of triacylglycerols. Characteristics common to coniferophytes and cycadophytes
Authors: Wolff Robert L. , Christie William W. , Pédrono Frédérique , Marpeau Anne M. , Tsevegsüren Nanzad , Aitzetmüller Kurt , Gunstone Frank D.
Published: November 2006

The fatty acid compositions of the seed lipids from four Ephedra species, E. nevadensis, E. viridis, E. przewalskii, and E. gerardiana (four gymnosperm species belonging to the Cycadophytes), have been established with an emphasis on Δ5‐unsaturated polymethylene‐interrupted fatty acids (Δ5‐UPIFA). Mass spectrometry of the picolinyl ester derivatives allowed characterization of 5,9‐ and 5,11–18∶2; 5,9,12–18∶3; 5,9,12,15–18∶4; 5,11–20∶2; 5,11,14–20∶3; and 5,11,14,17–20∶4 acids. Δ5‐UPIFA with a Δ11‐ethylenic bond (mostly C20 acids) were in higher proportions than δ5‐UPIFA with a δ9 double bond (exclusively C18 acids) in all species. The total δ5‐UPIFA content was 17–31% of the total fatty acids, with 5, 11, 14–20∶3 and 5, 11, 14, 17–20∶4 acids being the principal δ5‐UPFIA isomers. The relatively high level of cis‐vaccenic (11–18∶1) acid found in Ephedra spp. seeds, the presence of its δ5‐desaturation product, 5, 11–18∶2 acid (proposed trivial name: ephedrenic acid), and of its elongation product, 13–20∶1 acid, were previously shown to occur in a single other species, Ginkgo biloba, among the approximately 170 gymnosperm species analyzed so far. Consequently, Ephedraceae and Coniferophytes (including Ginkgoatae), which have evolved separately since the Devonian period (≈300 million yr ago), have kept in common the ability to synthesize C18 and C20 δ5‐UPIFA. We postulate the existence of two δ5‐desaturases in gymnosperm seeds, one possibly specific for unsaturated acids with a δ9‐ethylenic bond, and the other possibly specific for unsaturated acids with a δ11‐ethylenic bond. Alternatively, the δ5‐desaturases might be specific for the chain length with C18 unsaturated acids on the one hand and C20 unsaturated acids on the other hand. The resulting hypothetical pathways for the biosynthesis of δ5‐UPIFA in gymnosperm seeds are only distinguished by the position of 11–18∶1 acid. Moreover, 13C nuclear magnetic resonance spectroscopy of the seed oil from two Ephedra species has shown that δ5‐UPIFA are essentially excluded from the internal position of triacylglycerols, a characteristic common to all of the Coniferophytes analyzed so far (more than 30 species), with the possibility of an exclusive esterification at the sn‐3 position. This structural feature would also date back to the Devonian period, but might have been lost in those rare angiosperm species containing δ5‐UPIFA.
Preparation, separation, and confirmation of the eight geometrical cis/trans conjugated linoleic acid isomers 8,10‐through 11,13–18∶2
Authors: Eulitz Klaus , Yurawecz Martin P. , Sehat Najibullah , Fritsche Jan , Roach John A. G. , Mossoba Magdi M. , Kramer John K. G. , Adlof Richard O. , Ku Yuoh
Published: November 2006

Conjugated linoleic acid (CLA) mixtures were isomerized with p‐toluenesulfinic acid or I2 catalyst. The resultant mixtures of the eight cis/trans geometric isomers of 8,10‐, 9,11‐, 10,12‐, and 11,13‐octadecadienoic (18∶2) acid methyl esters were separated by silver ion‐high‐performance liquid chromatography (Ag+‐HPLC) and gas chromatography (GC). Ag+‐HPLC allowed the separation of all positional CLA isomers and geometric cis/trans CLA isomers except 10,12–18∶2. However, one of the 8,10 isomers (8cis, 10trans‐18∶2) coeluted with the 9trans,11cis18∶2 isomer. There were differences in the elution order of the pairs of geometric CLA isomers resolved by Ag+‐HPLC. For the 8,10 and 9,11 CLA isomers, cis,trans eluted before trans,cis, whereas the opposite elution pattern was observed for the 11,13–18∶2 geometric isomers (trans,cis before cis,trans). All eight cis/trans CLA isomers were separated by GC on long polar capillary columns only when their relative concentrations were about equal. Large differences in the relative concentration of the CLA isomers found in natural products obscured the resolution and identification of a number of minor CLA isomers. In such cases, GC‐mass spectrometry of the dimethyloxazoline derivatives was used to identify and confirm coeluting CLA isomers. For the same positional isomer, the cis,trans consistently eluted before the trans,cis CLA isomers by GC. High resolution mass spectrometry (MS) selected ion recording (SIR) of the molecular ions of the 18∶1 18∶2, and 18∶3 fatty acid methyl esters served as an independent and highly sensitive method to confirm CLA methyl ester peak assignments in GC chromatograms obtained from food samples by flame‐ionization detection. The high‐resolution MS data were used to correct for the nonselectivity of the flame‐ionization detector.
Mechanisms mediating lipoprotein responses to diets with medium‐chain triglyceride and lauric acid
Authors: Tsai Yu‐Hwai , Park Sunmin , Kovacic Jeffery , Snook Jean T.
Published: November 2006

Medium‐chain triglycerides (MCT) are often used in specialized formula diets or designer fats because of their special properties. Yet their influence on lipid metabolis is not completely understood. In this two‐period cross‐over study, the effects of MCT (8∶0+10∶0) in contrast to a similar saturated fatty acid (12∶0) were compared. Eighteen healthy women ate a baseline diet [polyunsaturated (PUFA)/saturated fat=0.9] fer 1 wk. Then, they consumed test diets (PUFA/saturated fat=0.2) for 4 wk. Monounsaturated fat and cholesterol were constant in baseline and treatment diets. MCT and 12∶0, substituted for part of the PUFA, provided 14 energy (en)% of the test diets. In comparison to the PUFA baseline diet, a 16% increase in mean serum low density lipoprotein (LDL)‐cholesterol (C) on the 12∶0 diet was accompanied by a 21% decrease in mean receptormediated degradation of LDL by freshly isolated mononuclear cells (MNC) in vitro. The MNC assay theoretically gives an indication of receptor‐mediated degradation of LDL. In contrast, the MCT diet raised mean receptor‐mediated degradation of LDL by 42%, a finding out of line with the mean 11% increase in serum LDL‐C. Perhaps MCT, by increasing the rate of LDL‐C production, overcame the rate of LDL‐C clearance. The 12∶0 diet enhanced some factors involved in reverse cholesterol transport (e.g., high density lipoprotein fractions) while MCT had a different of less pronounced effect. The overall effects of MCT on cholesterol metabolism may or may not be desirable, whereas those of 12∶0 appear largely undesirable as previously reported.
Eicosapentaenoic acid and docosahexaenoic acid selectively attenuate U46619‐induced smooth muscle cell proliferation
Authors: Pakala Rajbabu , Pakala Rajashree , Benedict Claude
Published: November 2006

It is well known that vascular smooth muscle cell (SMC) proliferation is a key step in atheromatous plaque formation. Thromboxane A2 (T×A2), released from aggregating platelets and an injured vessel wall, may play an important role in the development of atheromatous plaque. Many animal studies have suggested that n−3 polyunsaturated fatty acids eicosapentaenoic acid (EPA, 20∶5n−3) and docosahexaenoic acid (DHA, 22∶6n−3) present in the fish oils have antiatherosclerotic effects. In the present study, we investigated the effect of EPA and DHA on I×A2‐induced SMC proliferation. To determine the functional selectivity of n−3 fatty acids, we also tested the effect of arachidonic acid (AA, 20∶4n−6), γ‐linolenic acid) (INA, 18∶3n−6), and oleic acid (OA, 18∶1n−9) on T×A2‐induced SMC proliferation. Only LPA and DHA prevented the SMC proliferation induced by the T×A2 mimetic U46619. When EPA and DHA were added together in the ratio in which they are present in menhaden oil, EPA and DHA acted synergistically to block the SMC proliferation induced by the TXA2‐mimetic. These findings suggest that the n−3 polyunsaturated fatty acids in fish oils may exert antiatherosclerotic effects by blocking the mitogenstimulated proliferation of SMC.
Induction of apoptosis and apoptotic mediators in balb/C splenic lymphocytes by dietary n−3 and n−6 fatty acids
Authors: Avula C. P. Reddy , Zaman A. K. , Lawrence R. , Fernandes G.
Published: November 2006

The present study was designed to investigate the effect of diatery n−6 and n−3 polyunsaturated fatty acids (PUFA) on anti‐CD3 and anti‐Fas antibody‐induced apoptosis and its mediators in mouse spleen cells. Nutritionally adequate semipurified diets containing either 5% w/w corn oil (n−6 PUFA) or fish oil (n−3 PUFA) were fed to weanling female Balb/C mice, and 24 wk later mice were sacrificed. In n−3 PUFA‐fed mice, serum and splenocyte lipid peroxides were increased by 20 and 28.3% respectively, compared to n−6 PUFA‐fed mice. Further, serum vitamin F levels were decreased by 50% in the n−3 PUFA‐fed group, whereas higher anti0Fas‐ and anti‐CD3‐induced apoptosis (65 and 66%) and necrosis (17 and 25%), compared to the n−6 PUFA‐fed group, were found when measured with Annexin V and propidium iodide staining, respectively. In addition, decreased Bcl‐2 and increased Fas‐ligand (Fas‐L) also were observed in the n−3 PUFA‐fed group compared to the n−6 PUFA‐fed group. No difference in the ratio of splenocyte subsets nor their Fas expression was observed between the n−3 PUFA‐fed and n−6 PUFA‐fed groups, whereas decreased proliferation of splenocytes was found in n−3 PUFA‐fed mice compared to n−6 PUFA‐fed mice. In conclusion, our results indicate that dietary n−3 PUFA induces higher apoptosis by increasing the generation of lipid peroxides and elevating Fas‐L expression along with decreasing Bcl‐2 expression. A reduced proliferative response of immune cells also was observed in n−3 PUFA‐fed mice.