bluuebunny/crossref_metadata_2025 huggingface dataset:
FA Composition of plasma, red blood cell, and liver phospholipids of newborn piglets fed trans isomers of α‐linolenic acid
Authors: Acar Niyazi , Chardigny Jean‐Michel , Berdeaux Olivier , Almanza Simone , Sébédio Jean‐Louis
Published: November 2006

The effects of dietary cis and trans α‐linolenic acid (18∶3n−3) on the FA composition of plasma, red blood cell, and liver phospholipids were studied in newborn piglets. Animals were fed for 14 d with one of three diets: a control diet (group A) containing cis 18∶3n−3 at a level of 2.0% of total FA, a diet (group B) in which a part of the 18∶3n−3 acid was isomerized (1.3% of cis 18∶3n−3 and 0.7% of trans 18∶3n−3), or a diet (group C) with 2.0% cis 18∶3n−3 and 0.7% trans 18∶3n−3. Feeding animals with diets containing trans 18∶3n−3 resulted in the presence of trans isomers of 18∶3n−3, trans isomers of EPA, and trans isomers of DHA in phospholipids; however, the level of total trans n−3 PUFA in tissues was less than 0.3% of total tissue FA. In group B, the reduction of dietary amounts of cis 18∶3n−3 was associated with a decrease in individual and total cis n−3 PUFA. In contrast, in group C there was no decrease in tissue n−3 PUFA despite the increased dietary level of trans 18∶3n−3. These results suggest that the isomerization of a part of dietary n−3 PUFA, leading to the reduction of their levels in the diet, could induce a decrease in n−3 PUFA in phospholipids. The physiological effects of trans PUFA are not known and should be considered in future studies.
Dolichol levels in younger and older rat hearts heterotopically transplanted in younger recipients
Authors: Cavallini Gabriella , Parentini Ilaria , Di Stefano Rossella , Maccheroni Marco , Masini Matilde , Pollera Maria , Gori Zina , Masca Franco , Bergamini Ettore
Published: November 2006

Dolichol (D) levels increase dramatically in older tissue. An understanding of the exchangeability of D between tissues may be essential in order to understand the mechanism of the abnormal accumulation associated with aging. The question was investigated by the use of organ transplantation. D‐poor hearts donated by 3‐mon‐old and D‐rich by 22‐mon‐old male Lewis rats were transplanted heterotopically in 3‐mon‐old syngenic recipients, whose peripheral tissues and liver were poor in D. Native and transplanted hearts were taken 7 and 21 d after surgery. Native hearts of 3‐mon‐ and 22‐mon‐old male Lewis rats served as control. D concentration and quantity were higher in older than in younger native hearts as expected. In the transplanted hearts, the quantity of D was unchanged, irrespective of the age of the donor and of the time of transplantation, whereas D concentration increased because of the remarkable disuse atrophy. No changes in D were observed in recipients’ tissues. It is concluded that dolichol is not redistributed via circulation from the transplanted heart to the tissues and liver of the younger recipient.
Total synthesis of 2‐methoxy‐14‐methylpentadecanoic acid and the novel 2‐methoxy‐14‐methylhexadecanoic acid identified in the sponge agelas dispar
Authors: Carballeira Néstor M. , Cruz Heidyleen , Ayala Norma L.
Published: November 2006

The phospholipid FA composition of the Carbbean sponge Agelas dispar was revisited and 40 different FA were identified. Among these a novel 2‐methoxylated FA, namely, the anteiso methyl‐branched 2‐methoxy‐14‐methylhexadecanoic acid, was identified together with the recently discovered iso methyl‐branched 2‐methoxy‐14‐methylpentadecanoic acid and the normal‐chain 2‐methoxytetradecanoic acid. The structures of the iso and anteiso methyl‐branched 2‐methoxylated FA were confirmed by total syntheses, which were accomplished in seven steps and in 45–48% overall yields. Other phospholipid FA identified in A. dispar include the unusual methyl‐branched 10, 130dimethyltetradecanoic acid, 3,7,11,15‐tetramethylhexadecanoic (phytanic) acid, and the 11‐methyloctadecanoic acid. In addition, the Δ5,9 FA (5Z, 9Z)‐15‐methyl‐5,9‐hexadecadienoic acid and (5Z, 9Z)‐5,9‐octadecadienoic acid were characterized. These findings establish alternative FA biosynthetic possibilities for these marine organisms.
Fatty acid mobilized by the vascular endothelial growth factor in human endothelial cells
Authors: Boccellino Mariarosaria , Giovane Alfonso , Servillo Luigi , Balestrieri Ciro , Quagliuolo Lucio
Published: November 2006

Release of FFA from membrane phospholipids was observed after incubation of umbilical cord vein‐derived endothelial cells (HUVEC) with vascular endothelial growth factor (VEGF). In particular, we found an increase of arachidonate, stearate, and palmitate in a time‐dependent manner with a peak at 30 min. The maximum increase was reached by arachidonate (4.4‐fold), followed by stearate (2.2‐fold) and palmitate (1.3‐fold). The arachidonate increase can be ascribed to the activation of phospholipase A2 (PLA2). In fact, cells preincubated with arachidonyl trifluoromethyl ketone, a PLA2 inhibitor, showed a marked reduction in arachidonate mobilization. The role of Ca2+ in PLA2 activation was also investigated. Cells incubated with VEGF in the presence of EGTA showed a marked decrease in arachidonate mobilization, whereas incubation with the calcium ionophore A23187 alone produced an increase in arachidonate, although to a lesser extent compared with the VEGF stimulation. Incubation with A23187 in association with PMA produced the same increase in arachidonate as the VEGF treatment. Mitogen‐activated protein kinase (MAPK) activity was also found to increase as a consequence of VEGF stimulation. Taken together, these results suggest that the VEGF‐mediated activation of PLA2 in HUVEC is dependent on both MAPK‐mediated phosphorylation and Ca2+ increase. Furthermore, the increase in stearate and palmitate likely is brought about by the activation of a pathway involving phospholipase D, phosphatidate phosphohydrolase (PAP), and DAG lipase. In fact, the increase in those FFA was prevented when HUVEC were stimulated with VEGF in the presence of ethanol (which inhibits the formation of phosphatidate), propranolol (a specific inhibitor of PAP), or RHC‐80267 (a specific inhibitor of DAG lipase).
Dietary flax oil reduces renal injury, oxidized LDL content, and tissue n−6/n−3 FA ratio in experimental polycystic kidney disease
Authors: Ogborn Malcolm R. , Nitschmann Evan , Bankovic‐Calic Neda , Weiler Hope A. , Aukema Harold
Published: November 2006

As whole flaxseed is beneficial in the treatment of experimental renal disease, we undertook a study to determine whether previously documented benefits of whole flaxseed could be reproduced with dietary low‐lignan flax oil (FO), a rich source of α‐linolenic acid, in experimental polycystic kidney disease. Male offspring of Han:SPRD‐cy heterozygous rats were fed a synthetic diet containing FO or corn oil (CO) for 8 wk from the time of weaning. Renal inflammation, fibrosis, proliferation, cystic change, and oxidized‐LDL were assessed morphometrically. Hepatic and renal lipid composition was assessed using GC. FO feeding produced hepatic and renal enrichment of n−3 PUFA and an increase in C18∶>C18 PUFA ratios (18‐carbon PUFA compared to longer‐chain PUFA), with a reduction in proportion of hepatic long‐chain PUFA. The FO‐based diet was associated with lower mean cystic change by 29.7% (P=0.018), fibrosis by 21.7% (P=0.017), macrophage infiltration by 31.5% (P< 0.0001), epithelial proliferation by 18.7% (P=0.0035), and ox‐LDL detection by 31.4% (P<0.0001) in Han:SPRD‐cy heterozygotes. Serum creatinine was significantly lower in FO‐fed diseased animals. A small hypocholesterolemic effect was noted in all animals fed FO. FO feeding moderates renal injury, modifies the profile of substrates available for elongation to eicosanoid precursors, and inhibits the elongation of C18 PUFA in this model. The consumption of FO‐based products may prove a more practical way of obtaining health benefit than attempts to increase dietary content of unrefined seed.
Effects of dietary α‐linolenic acid from blended oils on biochemical indices of coronary heart disease in indians
Authors: Ghafoorunissa  , Vani A. , Laxmi R. , Sesikeran B.
Published: November 2006

PUFA of the n−6 and n−3 series have beneficial effects on key risk factors of coronary heart disease (CHD). Our earlier studies on the intake of FA and on the FA composition of plasma and platelet phospholipids suggested the need to improve the n−3 PUFA nutritional status in the Indian population. The present long‐term study was conducted on 80 middle‐aged Indian subjects (40 men and 40 women) using the subjects' own home‐prepared diets to evaluate the effects of dietary n−3 PUFA on biochemical indices of CHD risk. Substitution of Blend G (equal proportions of groundnut and canola oils) for groundnut oil or substitution of Blend S (equal proportions of sunflower and canola oils) for sunflower oil increased α‐linolenic acid (ALNA) fourfold and decreased the linoleic acid (LA)/ALNA ratio from 35 to 6 and 65 to 9, respectively. Twelve subjects (six men and six women) who received Blend G were switched back to groundnut oil and were administered 0.3 g daily of long‐chain (LC) n−3 PUFA from fish oil. At the end of the trial period for both blends in both sexes, plasma lipid and apolipoprotein levels had not changed, and ADP‐induced aggregation had decreased. In plasma and platelet phospholipids, LA as well as LCn‐3 PUFA had increased, suggesting competition between LA and ALNA for metabolism into the respective LC‐PUFA. Fish oil supplementation increased LCn‐3 PUFA in plasma and platelet phospholipids, decreased ADP‐induced platelet aggregation, and increased plasma cholesterol. On the basis of the increased LCn‐3 PUFA in plasma phospholipids, it was calculated that 0.75% energy (en%) (2.2 g) ALNA (from vegetable oils) may be required to increase LCn‐3 PUFA to about the same extent as 0.1 en% (0.3 g) LCn‐3 PUFA (from fish oils). Since both n−6 and n−3 PUFA play a critical role in fetal growth and development and in the programming of diet‐related chronic diseases in adults, an improvement in the n−3 PUFA nutritional status in cereal‐based diets through long‐term use of cooking oils containing 25–40% LA and 4% ALNA may contribute to the prevention of CHD in Indians.
5,9,23‐Triacontatrienoic methyl ester, an elastase inhibitor from the marine sponge Chondrilla nucula
Authors: Meyer Michèle , Guyot Michèle
Published: November 2006

A polyethylenic fatty ester was isolated from the marine sponge Chondrilla nucula. The structure was elucidated through NMR spectral data and MS analysis as 5,9,23‐triacon‐tatrienoic methyl ester 1. Compound 1 is an elastase inhibitor [ID50=10 μg/mL (2·10−5M)].
Dietary CLA decreased weight loss and extended survival following the onset of kidney failure in NZB/W F1 mice
Authors: Yang Mingder , Cook Mark E.
Published: November 2006

In an earlier study, we showed that feeding CLA immediately after weaning prolonged survival of NZB/W F1 mice after onset of proteinuria. In the present study, the feeding of CLA was delayed until mice had developed proteinuria. Thirty NZB/W F1 mice were fed a regular rodent chow after weaning. Urine samples were collected to detect proteinuria. Once a mouse was proteinuria positive, it was then randomly assigned to a 0.5% CLA supplement semipurified diet or a control diet (supplement 0.5% corn oil). The next proteinuria positive mouse was then assigned to the opposite diet to which the first mouse was assigned. Mice fed the control diet lost 25% more body weight (13.0 g) than mice fed the CLA diet (9.7 g). Moreover, CLA‐fed mice survived an average 1.7‐fold longer (148 d) than mice fed the control diet (89 d) after the onset of proteinuria. This follow‐up study confirmed that dietary CLA had a beneficial effect in the autoimmune NZB/W F1 mouse. In summary, the cachectic symptom of systemic lupus erythematosus was decreased by dietary CLA and survival days were increased over control group.
Pyloric ceca are significant sites of newly synthesized 22∶6n−3 in rainbow trout (Oncorhynchus mykiss)
Authors: Bell M. V. , Dick J. R. , Porter A. E. A.
Published: November 2006

In this pulse‐chase study, rainbow trout fed a diet containing deuterated (D5) (17,17,18,18,18)‐18∶3n−3 ethyl ester accumulated D5‐22∶6n−3 in pyloric ceca to a greater extent than in liver 2 d post‐dose. The ratio of newly synthesized D5‐22∶6n−3 in ceca to that in liver 2 d after feeding D5‐18∶3n−3 was 4.7±1.2 when expressed as per mg tissue and 5.2±2.4 when expressed as per mg protein. The amount of D5‐22∶6n−3 in ceca then declined whereas that in liver and blood increased, with the ratio of ceca to liver falling to 1.7 and 1.4, respectively, by day 5 and approaching unity by day 9. A crude cecal mucosa fraction contained 123±50 ng D5‐22∶6n−3/mg protein/mg D5‐18∶3n−3 eaten 2 d after feeding the tracer, compared with 35±21 ng D5‐22∶6n−3/mg protein/mg D5‐18∶3n−3 eaten in liver. Three days later the amount in cecal mucosa had fallen by one‐third and that in liver had increased threefold. Most of the D5‐18∶3n−3 was catabolized very rapidly. The ratio of D5‐18∶3n−3 to 21∶4n−6 (a relatively inert FA marker) in the diet was 4.0, but this fell to 0.30 in ceca and ca. 0.8 in liver, blood, and whole carcass one day after feeding. These results indicate that ceca are active in the synthesis of 22∶6n−3 and the oxidation of 18∶3n−3.
Dual action of neutral sphingomyelinase on rat hepatocytes: Activation of cholesteryl ester metabolism and biliary cholesterol secretion and inhibition of VLDL secretion
Authors: Liza Mariana , Chico Yolanda , Fresnedo Olatz , Ochoa Begoña
Published: November 2006

To address the role of cell membrane neutral sphingomyelinase (EC 3.1.4.12; SMase) in the regulation of cholesterol metabolism in the liver parenchymal cell, we examined the effect of exogenous neutral SMase on the metabolism of cholesteryl esters and the secretion of VLDL and biliary lipids in isolated rat hepatocytes. We show that treatment of hepatocytes with SMase (20 mU/mL) resulted in the intracellular buildup of cholesteryl esters, increased ACAT (EC 2.3.1.26) activity without affecting the ACAT2 mRNA level, and increased cytosolic and microsomal cholesteryl ester hydrolase (EC 3.1.1.13) activity. This was accompanied by increases in the secretion of biliary. bile acid, phospholipid, and cholesterol and in increased cholesterol 7α‐hydroxylase (EC 1.14.13.17) activity and levels of mRNA, as well as decreased levels of apoB mRNA and a decreased secretion of VLDL apoB (apoB‐48, ∼45%; apoB‐100, ∼32%) and lipids (∼55%). Moreover, the VLDL particles secreted had an abnormal size and lipid composition; they were larger than controls, were relatively enriched in cholesteryl ester, and depleted in TG and cholesterol. Cell‐permeable ceramides did not replicate any of the reported effects. These findings demonstrate that the increased cholesteryl ester turnover, oversecretion of biliary cholesterol and bile acids, and undersecretion of VLDL cholesterol and particles are concerted responses of the primary hepatocytes to exogenous neutral SMase brought about by regulation at several levels. We suggest that plasma membrane neutral SMase may have a specific, ceramide‐independent effect in the regulation of cholesterol out‐put pathways in hepatocytes.
Conjugated methyl sulfide and phenyl sulfide derivatives of oxidosqualene as inhibitors of oxidosqualene and squalene‐hopene cyclases
Authors: Rocco Flavio , Bosso Simonetta Oliaro , Viola Franca , Milla Paola , Roma Giorgio , Grossi Giancarlo , Ceruti Maurizio
Published: November 2006

Various (1E,3E)‐ and (1Z,3E)‐conjugated methylthio derivatives of oxidosqualene (OS) and conjugated and non‐conjugated phenylthio derivatives of OS were obtained. These compounds, designed as inhibitors of pig liver and Saccharomyces cerevisiae 2,3‐oxidosqualene‐lanosterol cyclases (OSC) (EC 5.4.99.7) and of Alicyclobacillus acidocaldarius squalenehopene cyclase (SHC) (EC 5.4.99.‐), contain the reactive function adjacent to carbons involved in the formation of the third and the fourth cycle during OS cyclization. All the new compounds are inhibitors of OSC and SHC, with various degrees of selectivity. The conjugated methylthio derivatives behaved as potent inhibitors of S. cerevisiae OSC, whereas most of the phenylthio derivatives were especially active toward SHC.
Eicosapentaenoic acid‐induced apoptosis depends on acyl CoA‐synthetase
Authors: Heimli Hilde , Hollung Kristin , Drevon Christian A.
Published: November 2006

Marine n−3 FA are known to inhibit proliferation or induce cell death in several cancer cell lines. We have previously reported that EPA promotes apoptosis in the lymphoma cell line Ramos, whereas the U‐698 cell line is insensitive to EPA. Furthermore, acyl‐CoA synthetase (ACS) is expressed to a higher extent in Ramos cells compared to U‐698 cells. To investigate the importance of ACS in EPA‐induced apoptosis, we incubated Ramos cells with triacsin C, an inhibitor of ACS. This caused a 70% reduction in the amount of cell‐associated EPA and diminished activation of EPA. In addition, triacsin C caused a 90% reduction in EPA‐induced apoptosis. Several different approaches were tried to overexpress ACS4 in EPA‐insensitive lymphoma cell lines, but we did not obtain viable cells with high expression of acyl‐CoA activation. However, we show that overexpression of ACS4 in the more robust COS‐1 cells caused up to a fivefold increase in activation of EPA and a 67% increase in the amount of cell‐associated radiolabeled EPA. Furthermore, we observed 28% elevated cellular level of TAG in EPA‐incubated COS‐1 cells overexpressing ACS4. The present study provides new information about ACS as an important enzyme for EPA‐induced apoptosis in Ramos cells. Our data offer a potential mechanism that may explain the effect of dietary marine n−3 PUFA on growth of certain malignant cells.
Ethyl arachidonate is the predominant fatty acid ethyl ester in the brains of alcohol‐intoxicated subjects at autopsy
Authors: Refaai M. A. , Nguyen P. N. , Cluette‐Brown J. E. , Laposata M.
Published: November 2006

The role of fatty acid ethyl esters (FAEE), the nonoxidative ethanol metabolites, as mediators of alcohol‐induced organ damage is increasingly being recognized. FAEE are detectable in the blood and in liver and adipose tissue after ethanol ingestion, and on that basis, FAEE can be used as markers of ethanol intake. In this study, 10 samples of human brain were collected at autopsy at the Massachusetts Medical Examiner's Office and analyzed for FAEE. FAEE were isolated and quantified as mass per gram of wet weight. The blood ethanol level was also obtained in each case along with the other drugs detected in routine postmortem toxicology screening tests. Ethyl arachidonate was the predominant FAEE species in the brain, representing up to 77.4% of total FAEE in the brain. The percent age of ethyl arachidonate of the total FAEE in the brain was significantly higher than what has been found in all other organs and tissues previously analyzed. Linoleate, the precursor of arachidonate, was a poor substrate for FAEE synthesis, as the percentage of ethyl linoleate of the total FAEE content was extremely low. Thus, this reflects preferred incorporation of arachidonate into newly synthesized FAEE in the brain. Since arachidonate is derived from linoleate, which is depleted in FAEE while arachidonate is enriched, the synthesis of FAEE may be linked to the desaturation and elongation of linoleate to arachidonate.
Effects of red wine consumption on kidney FA composition
Authors: Araya Julia , Rodrigo Ramón , Orellana Myriam , García Vanessa
Published: November 2006

We studied the effects of red wine consumption on the FA composition of rat kidney. Four groups of adult male rats were fed a balanced diet for 10 wk. The drinking fluid was water (control), red wine, alcohol‐free red wine, or ethanol (12.5%, vol/vol). FA composition, lipid peroxidation, and cytochrome P450 content were determined in the kidney. The antioxidant capacity of plasma was also measured. Ethanol decreased the content of long‐chain PUFA, whereas red wine maintained the levels of arachidonic (20∶4n−6) and eicosapentaenoic (20∶5n−3) acids and alcohol‐free red wine significantly increased the levels of 20∶4n−6. Lipid peroxidation in the red wine and alcohol‐free red wine groups was significantly lower than that of both the control and ethanol groups. The diminished renal lipid peroxidation was associated with an increased antioxidant capacity of plasma. Renal cytochrome P450 was elevated by 50% in the ethanol group and diminished by 20% in the alcohol‐free red wine group. These data suggest that moderate red wine consumption could contribute to the preservation of the contents of n−3 and n−6 PUFA, particularly 20∶4n−6, in rat kidney. Although ethanol increased the content of cytochrome P450 in the kidney, this effect was eliminated by the nonalcoholic components of red wine.
Combined effects of EFA deficiency and tumor necrosis factor‐α on circulating lipoproteins in rats
Authors: Levy Emile , Delvin Edgard , Peretti Noel , Bouchard Guylaine , Seidman Ernest
Published: November 2006

Both tumor necrosis factor‐α (TNF‐α) and EFA deficiency (EFAD) have been established as causes of marked perturbations in lipid and lipoprotein metabolism. Excessive levels of circulating TNF‐α can coexist with EFAD in various clinical disorders such as cystic fibrosis and type I diabetes. The present study therefore aimed to investigate their combined effects on lipid profile and lipoprotein composition by administering TNF‐α to EFAD rats. Lipoprotein lipase (LPL), the ratelimiting enzyme in TG catabolism, was also measured in epididymal adipose tissue. EFAD, after a 4‐wk period, induced significant increases in plasma TG (80%, P<0.001), total cholesterol (TC, 27%, P<0.025), and HDL‐cholesterol (HDL‐C, 62%). Two hours after the administration of TNF‐α, a further rise in TG (43%, P<0.05) was noted in controls, but not EFAD animals. TC and HDL‐C were unaffected by TNF‐α treatment. In addition, TNF‐α modified lipoprotein‐lipid composition. VLDL and HDL2 derived from EFAD rats were depleted in apolipoprotein (apo) E and apo A‐II, and enriched in apo A‐12 h after TNF‐α administration. Finally, TNF‐α decreased adipose tissue LPL activity in both control and EFAD animals. The TNF‐α‐induced inhibition was more marked in EFAD rats. The present results demonstrated that TNF‐α can amplify or antagonize the effects of EFAD on lipid profile, lipoprotein composition, and LPL activity. These data also suggest that the host's nutritional status is a determining factor for the modulating effect of TNF‐α on lipid metabolism.
Differences in CLA isomer distribution of cow's milk lipids
Authors: Kraft Jana , Collomb Marius , Möckel Peter , Sieber Robert , Jahreis Gerhard
Published: November 2006

The uniqueness of ruminant milk lipids is based on their high concentration of CLA. Maximal CLA concentrations in milk lipids require optimal conditions of ruminal fermentation and substrate availability, conditions like those present in pasture‐fed cows. Our previous work showed that farm management (indoor feeding vs. pasture feeding) markedly influenced the CLA concentration. In this study, the objective was to evaluate the influence of the farm management system as dependent on different locations. Milk samples from different locations (Thuringia and the Alps, representing diverse altitudes) were collected during the summer months and analyzed for FA profile and CLA isomer distribution. The proportion of PUFA and total CLA in milk fat was significantly lower in milk from indoor cows compared with the pasture cows in the Alps. The trans‐11 18∶1 in milk fat of Alpine cows was elevated, in contrast to lower values for trans‐10 18∶1. Milk from cows grazing pasture in the Alps was higher in EPA and lower in arachidonic acid than milk from indoor‐fed cows. The proportion of cis,trans/trans,cis isomers of CLA was 10 times higher from the indoor cows than from the Alpine cows. In addition to the major isomer cis‐9,trans‐11, this difference also occurred for the trans‐11,cis‐13 isomer, which represented more than a fourth of the total CLA present in milk fat. This is the first report showing a special isomer distribution in the milk fat of cows living under very natural conditions. We hypothesize that the CLA isomer trans‐11,cis‐13 is formed in large quantity as a result of grazing mountain pasture, which is rich in α‐linolenic acid.
Determination of the phospholipase activity of patatin by a continuous spectrophotometric assay
Authors: Jiménez‐Atiénzar M. , Cabanes J. , Gandía‐Herrero F. , Escribano J. , García‐Carmona F. , Pérez‐Gilabert M.
Published: November 2006

Patatin is a family of glycoproteins that accounts for 30–40% of the total soluble protein in potato (Solanum tuberosum L.) tubers. This protein has been reported to serve as a storage protein and also to exhibit lipid phospholipase activity. This paper describes a simple continuous spectrophotometric method for assaying patatin phospholipase activity. The procedure is based on a coupled enzymatic assay using [1,2‐dilinoleoyl]PC as the phospholipase substrate and lipoxygenase as the coupling enzyme. In the procedure developed in this work, lipoxygenase oxidizes the linoleic acid released by the phospholipase activity of patatin. This activity can then be followed spectrophotometrically by recording the increase in absorbance at 234 nm that results from the formation of the corresponding hydroperoxide from linoleic acid by the action of lipoxygenase. The optimal assay concentrations of patatin and lipoxygenase were established. Phospholipase activity varied with pH, reaching its optimal value at pH 9.5. Scans of the deoxycholate concentration pointed to an optimal detergent concentration of 3 mM. Phospholipid hydrolysis followed classical Michaelis‐Menten kinetics (Vm=9.8×10−3 μmol/min·μg protein, Km=7.8 μM, Vm/Km=1.3 min−1·μg protein). This method proved to be specific since there was no activity in the absence of patatin. It also had the advantages of a short analysis time and the use of commercially nonradiolabeled and inexpensive substrates, which are, furthermore, natural substrates of phospholipase.
Effect of conjugated FA on feed intake, body composition, and liver FA in mice
Authors: Chardigny J. M. , Hasselwander O. , Genty M. , Kraemer K. , Ptock A. , Sébédio J. L.
Published: November 2006

CLA is a generic term describing different isomers of linoleic acid with two conjugated double bonds. Various metabolic effects have been demonstrated following administration of CLA, including a change in body composition in animals. However, the effects of pure CLA isomers are not fully understood. In addition, conjugated octadecatrienoic acids such as calendic acid have not been extensively investigated. In this study, male and female ICR mice were fed pure CLA isomers (cis9,trans11 or trans10,cis12) or calendic acid (trans8,trans10,cis12) as their ethyl esters for 6 wk. Body protein content was significantly increased after feeding CLA isomers, either as pure isomers or as a mixture. Calendic acid significantly decreased body fat content in males. CLA (pure isomers or a mixture) significantly decreased body fat in both males and females, with the trans10,cis12 isomer being the most effective. The effect of the cis9,trans11 isomer was more pronounced in females than in males. It was concluded that the trans10,cis12 CLA isomer was mainly responsible for the decrease in fat content in mice, without a significant modification of feed efficiency, and that it was more effective than calendic acid.
Stimulation of rat liver mitochondrial sn‐glycerol‐3‐phosphate acyltrasferase by polymyxin B via enhanced extraction of lysophosphatidic acid
Authors: Roy Arun , Guha Nilanjan , Veras Ingrid D. , Chakraborty Sanjoy , Haldar Dipak
Published: November 2006

The purpose of this investigation was to determine how polymyxin B stimulates the activity of mitochondrial glycerophosphate acyltransferase. Polymyxin B did not change the integrity of the mitochondrial outer membrane as judged by testing the latency (>80%) of cytochrome oxidase activity. The stimulation totally disappeared when polymyxin B‐treated mitochondria were washed. The FA side chain in polymyxin B was unnecessary for stimulation, as the nonapeptide was as effective as the whole antibiotic. The stimulation by polymyxin B or the nonapeptide was observed only in the presence of BSA. Cytochrome c, when added to the incubation medium instead of albumin, did not stimulate the mitochondrial enzyme, but did produce a stimulatory effect of polymyxin B on the mitochondrial acyltransferase. As reported earlier for the bacterial and microsomal acyltransferase, other polycationic compounds such as spermine and spermidine stimulated mitochondrial glycerophosphate acyltransferase. The stimulation of the mitochondrial acyltransferase by spermine and spermidine also occurred only in the presence of BSA. The analysis of the products of esterification demonstrated the presence of more lysophosphatidic acid (LPA) in the polymyxin B‐and polyamine‐stimulated assays in comparison to their respective control. Furthermore, in comparison to the albumin‐treated control, there was 60% more LPA present in the assay supernatant fractions of polymyxin B‐treated samples. Our results suggest that polymyxin B stimulates the mitochondrial glycerophosphate acyltransferase activity by enhancing the extraction of more LPA from the mitochondria to the supernatant fraction.
Electrophile tocopheryl quinones in apoptosis and mutagenesis: Thermochemolysis of thiol adducts with proteins and in cells
Authors: Cornwell David G. , Kim Sunghwan , Mazzer Paula A. , Jones Kenneth H. , Hatcher Patrick G.
Published: November 2006

Electrophile tocopheryl quinones from the phenolic antioxidants γ‐tocopherol and δ‐tocopherol form Michael adducts with the thiol nucleophile glutathione. These tocopheryl quinones are involved in cytotoxicity, apoptosis, and mutagenesis, and their biologic properties are associated with the depletion of intracellular thiols. We now show that both proteins and tissues treated with the electrophile γ‐tecopheryl quinone (γ‐TQ) form thiol adducts. The monoglutathion‐S‐yl derivative of γ‐TQ was subjected to thermochemolysis with the strong methylating base tetramethylammonium hydroxide. GC/MS showed four signature peaks and a fragmentation pattern characteristic of the thiol adduct. Similarly, pure monoglutathion‐S‐yl and diglutathion‐S‐yl derivatives of δ‐TQ were subjected to thermochemolysis, and GC/MS showed characteristic fragmentation patterns for thiol adducts. The four signature peaks were identified when pure proteins with accessible thiol groups (hemoglobin and histone), FBS, and tissue culture medium and cell preparations were treated with γ‐TQ. Signature peaks in both complete medium and washed cells showed the presence of both soluble and insoluble thiol adducts. The effective or free arylating electrophile concentration in complete medium should always be evaluated in tissue culture studies. γ‐TQ is a mutagen but not a genotoxin; therefore, the histone adduct may be a previously unrecognized histone modification involved in chromatin dynamics leading to mutagenesis.
Kinetics of barley FA hydroperoxide lyase are modulated by salts and detergents
Authors: Koeduka Takao , Stumpe Michael , Kajiwara Tadahiko , Feussner Ivo
Published: November 2006

The cDNA from barley coding FA hydroperoxide lyase (HPL) was cloned. A recombinant protein derived from the cDNA was expressed in Escherichia coli as an active enzyme. Thus far, there have been no reports on HPL in monocotyledonous plants. The recombinant protein was shown to be most active to linolenic acid 13‐hydroperoxide, followed by linoleic acid 13‐hydroperoxide. 9‐Hydroperoxides of the FA could not be substrates for the recombinant HPL. The activity was dramatically enhanced in the presence of a detergent and/or a salt in the reaction mixture. At the same time, the kinetics of the reaction, including inactivation and the Vmax value of the HPL, were also greatly modulated, depending on the concentration of a monovalent cation and/or a detergent in the reaction mixture. These results suggest that these effectors induced a conformational change in barley HPL, resulting in an improvement in substrate binding and in enzyme activity.
Programming of initial steps in bile acid synthesis by breat‐feeding vs. Formula‐feeding in the baboon
Authors: Mott Glen E. , Jackson Evelyn M. , Klein Marissa L. , Shan Hui , Pang Jihai , Wilson William K. , McMahan C. Alex
Published: November 2006

We tested the hypothesis that breast‐vs. formula‐feeding differentially affects the enzymatic activity of three sterol hydroxylases critical in the initial steps of bile acid formation. Thirty baboons were either breast‐fed or formula‐fed for the first 14 wk of life before weaning to baboon chow. At 14 and 34 wk of age, liver biopsies were assayed for cholesterol 7α‐hydroxylase (CYP7A1), 27‐hydroxycholesterol‐7α‐hydroxylase (CYP7B1), and cholesterol 27‐hydroxylase (CYP27A1). We also determined the kinetics of 3H‐27‐hydroxycholesterol (27‐OHC) turnover in vivo at both ages. At 14 wk of age, hepatic CYP7A1 activity was low but sevenfold higher among formula‐fed vs. breast‐fed baboons. By 34 wk, CYP7A1 activity had increased nearly 10‐fold in both infant diet groups, and the sevenfold difference in CYP7A1 between previously breast‐and formula‐fed animals persisted. There were no differences in CYP7B1 activities between infant diet groups at either 14 or 34 wk of age although the activity increased in both groups by about 50% from 14 to 34 wk. CYP27A1 activity also increased between 14 and 34 wk of age, and, compared with CYP7A1, relatively small differences in CYP27A1 activity due to infant diet were observed at each age. Plasma 27‐OHC turnover had a half‐time of 2–4 min. We had previously reported that after weaning, the total bile acid synthesis rate was higher among baboons that were formula‐fed than among breast‐fed animals. The present results suggest that this difference is most likely due to significantly higher CYP7A1 activity among formula‐fed vs. breast‐fed animals.
Comparative health effects of margarines fortified with plant sterols and stanols on a rat model for hemorrhagic stroke
Authors: Ratnayake W. M. N. , Plouffe L. , L'Abbé M. R. , Trick K. , Mueller R. , Hayward S.
Published: November 2006

There is increased acceptance of fortifying habitual foods with plant sterols and their saturated derivatives, stanols, at levels that are considered safe. These sterols and stanols are recognized as potentially effective dietary components for lowering plasma total and LDL cholesterol. Our previous studies have shown that daily consumption of plant sterols promotes strokes and shortens the life span of stroke‐prone spontaneously hypertensive (SHRSP) rats. These studies question the safety of plant sterol additives. The present study was performed to determine whether a large intake of plant stanols would cause nutritional effects similar to those seen with plant sterols in SHRSP rats. Young SHRSP rats (aged 26–29 d) were fed semipurified diets containing commercial margarines fortified with either plant stanols (1.1 g/100 g diet) or plant sterols (1.4 g/100 g diet). A reference group of SHRSP rats was fed a soybean oil diet (0.02 g plant sterols/100 g diet and no plant stanols). Compared to soybean oil, both plant stanol and plant sterol margarines significantly (P<0.05) reduced the life span of SHRSP rats. At the initial stages of feeding, there was no difference in the survival rates between the two margarine groups, but after approximately 50 d of feeding, the plant stanol group had a slightly, but significantly (P<0.05), lower survival rate. Blood and tissue (plasma, red blood cells, liver, and kidney) concentrations of plant sterols in the plant sterol margarine group were three to four times higher than the corresponding tissue concentrations of plant stanols in the plant stanol group. The deformability of red blood cells and the platelet count of SHRSP rats fed, the plant sterol margarine were significantly (P<0.05) lower than those of the plant stanol margarine and soybean oil groups at the end of the study. These parameters did not differ between the soybean oil and plant stanol margarine groups. These results suggest that, at the levels tested in the present study, plant stanols provoke hemorrhagic stroke in SHRSP rats to a slightly greater extent than plant sterols. The results also suggest that the mechanism by which plant stanols shorten the life span of SHRSP rat might differ from that of plant sterols.
Maternal dietary FA modulate the long‐chain n−3 PUFA status of chick cardiac tissue
Authors: Ajuyah A. O. , Cherian G. , Wang Y. , Sunwoo H. , Sim J. S.
Published: November 2006

The effect that egg yolk or maternal n−3 FA have on the cardiac tissue long‐chain n−3 FA status of chicks during growth was investigated. Fggs with low, medium, and high levels of n−3 PUFA were obtained by feeding breeder hens a wheat/soybean meal‐based diet containing 5% sunflower oil (Low n−3), 2.5% sunflower oil plus 2.5% fish oil (Medium n−3), or 5% fish oil (High n−3). The chicks hatched from Low, Medium, and High n−3 eggs were fed a diet containing 18∶3n−3, but devoid of long‐chain n−3 FA. The FA composition of cardiac tissue was determined on days 0, 14, 28, and 42. At day 0, the cardiac FA reflected maternal diet. With time, the level of all the long‐chain n−3 FA decreased compared with day 0, and this was true especially by day 14. These data show that dietary 18∶3n−3 fed to the chicks did not sustain high levels of EPA and DHA in cardiac tissue, despite the high content of long‐chain n−3 FA in the maternal diet. At days 0 and 14, the chicks hatched from High and Medium n−3 eggs had higher 20∶5n−3, 22∶5n−3, and 22∶6n−3 contents with a concomitant reduction in 20∶4n−6 in the cardiac tissue compared with the Low n−3 egg group. Cardiac tissue of birds hatched from Medium n−3 eggs retained higher levels of 20∶5n−3 up to day 42 of growth when compared with other treatments (P<0.05). None of the treatments was effective in maintaining DHA levels after day 14 of growth.
Linoleate diol synthase of the rice blast fungus Magnaporthe grisea
Authors: Cristea Mirela , Osbourn Anne E. , Oliw Ernst H.
Published: November 2006

Mycelia of two strains of Magnaporthe grisea, Guy 11 and TH3, were incubated with linoleic acid, and the metabolites were isolated and identified by GC‐MS and LC‐MS. The two main metabolites were identified as 8‐hydroxylinoleic and 7,8‐dihydroxylinoleic acids, and the former was further oxidized by n−2 and by n−3 hydroxylation to 8,16‐ and 8,17‐dihydroxylinoleic acids. Lipoxygenase metabolites of linoleic acid could not be detected. The sequence of the genome of M. grisea has been released from the Whitehead Institute; it contains a gene with close homology to the linoleate diol synthase gene of the take‐all fungus Gaeumannomyces graminis. Both genes appear to have the same organization, with four exons and three short introns, and the intron‐exon borders were determined by reverse‐transcription PCR and sequencing. The linoleate diol synthase precursor of G. graminis consists of 978 amino acids, whereas the putative diol synthase precursor of M. grisea contains 987 amino acids. The diol synthases of G. graminis and M. grisea can be aligned with 65% identical and 78% positive amino acid residues, and catalytically important amino acid residues were conserved.
Synthesis of novel tri‐ and tetrasubstituted C18 furan fatty esters
Authors: Lie Ken Jie Marcel S. F. , Lau Maureen M. L. , Lam Corey N. W.
Published: November 2006

A methylene‐interrupted C18 keto‐acetylenic fatty ester (methyl 12‐oxo‐9‐octadecynoate) was obtained from methyl ricinoleate by bromination‐dehydrobromination followed by oxidation. Reaction of methyl 12‐oxo‐9‐octadecynoate with bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl‐allyl bromide furnished methyl 8‐[5‐hexyl‐3‐allyl‐furan‐2‐yl]‐octanoate (1, 56%) or methyl 8‐[5‐hexyl‐3‐(2‐methyl‐allyl)‐furan‐2‐yl]‐octanoate (2, 55%). Reaction of methyl 12‐oxo‐11‐chloro‐or 11‐fluoro‐9‐octadeyynoate (prepared from methyl santalbate‐methyl 11‐E‐9‐octadecynoate, found in sandalwood, Santalum album, seed oil) with bis(benzonitrile) palladium(II) chloride gave methyl 8‐(4‐fluoro‐5‐hexyl‐furan‐2‐yl)‐octanoate (3, 50%) or methyl 8‐(4‐fluoro‐5‐hexyl‐furan‐2‐yl)‐octanoate (4, 50%), respectively. And when methyl 12‐oxo‐11‐chloro‐ or 11‐fluoro‐9‐octadecynoate was treated with a mixture of bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl‐allyl bromide, the reaction yielded tetrasubstituted C18 furan derivatives, viz, methyl 8‐(3‐allyl‐4‐chloro‐5‐hexyl‐furan‐2‐yl)‐octanoate (5, 54%), methyl 8‐[4‐chloro‐5‐hexyl‐3‐(2‐methyl‐allyl)‐furan‐2‐yl)‐octanoate (6, 54%), methyl 8‐(3‐allyl‐4‐fluoro‐5‐hexyl‐furan‐2‐yl]‐octanoate (7, 10%), and methyl 8‐[4‐fluoro‐5‐hexyl‐3‐(2‐methyl‐allyl)‐furan‐2‐yl]‐octanoate (8, 10%). The presence of a fluorine atom in the furan derivatives 4, 7, and 8 was readily characterized by the appearance of doublets for carbon nuclei, which were coupled to the fluorine atom in the 13C NMR spectra. All furan fatty derivatives from this work were characterized by NMR spectroscopic and mass spectrometric analyses. The yields of compounds 7 and 8 were very low (10%) despite attempts to improve the procedure by increasing the amounts of the reactants and catalyst.
Purification and characterization of an extracellular lipase from Geotrichum marinum
Authors: Huang Youliang , Locy Robert , Weete John D.
Published: November 2006

An extracellular lipase (EC 3.1.1.3) from Geotrichum marimum was purified 76‐fold with 46% recovery using Octyl Sepharose 4 Fast Flow and Bio‐Gel A 1.5 m chromatography. The purified enzyme showed a prominent band on SDS‐PAGE and a single band on native PAGE based on the activity staining. The molecular mass of the lipase was estimated to be 62 kDa using SDSPAGE and Bio‐Gel A chromatography, indicating that the lipase likely functions as a monomer. The pl of the lipase was determined to be 4.54. The apparent Vmax and Km were 1000 μmol/min/mg protein and 11.5 mM, respectively, using olive oil emulsified with taurocholic acid as substrate. The lipase demonstrated a pH optimum at pH 8.0 and a temperature optimum at 40°C. At 6 mM, Na+, K+, Ca2+, and Mg2+ stimulated activity, but Na+, and K+ at 500 mM and Fe2+ and Mn2+ at 6 mM reduced lipase activity. The anionic surfactant, taurocholic acid, and the zwitterionic surfactant, 3‐[(3‐cholamidopropyl)dimethylammonio]‐1‐propanesulfonate, enhanced the activity at 0.1 mM. Other anionic surfactants such as SDS and sodium dioctyl sulfosuccinate, the cationic surfactants methylbenzethonium bromide and cetyltriethylammonium bromide, and the nonionic surfactants Tween‐20 and Triton X‐100 inhibited the lipase activity to different extents. The lipase was found to have a preference for TG containing cis double bonds in their FA side chains, and the reaction rate increased with an increasing number of double bonds in the side chain. The lipase had a preference for ester bonds at the sn‐1 and sn‐3 positions over the ester bond at the sn‐2 position.
Regulation of diacylglycerol acyltransferase in developing seeds of castor
Authors: He Xiaohua , Chen Grace Q. , Lin Jiann‐Tsyh , McKeon Thomas A.
Published: November 2006

We have previously reported the cloning of castor diacylglycerol acyltransferase (RcDGAT) based on its homology to other plant type 1 diacylglycerol acyltransferases (DGATs). To elucidate the physiological role of the RcDGAT, we have investigated the regulation of RcDGAT expression in developing seeds of castor. The RcDGAT transcript appeared at 12 d after pollination (DAP), reached the highest level at 26 DAP, and declined rapidly after that. However, the RcDGAT protein started to accumulate at 26 DAP, reached its peak at 47 DAP, then remained at this high level until 54 DAP. The significant difference between the expression of mRNA and protein indicates that gene expression of RcDGAT in maturing castor seeds is controlled at the posttranscriptional level. We found that DGAT activity measured in microsomal membranes isolated from seed at different stages of development was parallel to RcDGAT protein level, suggesting DGAT activity is mainly a function of the level of RcDGAT protein. We monitored the triacylglycerol (TG) composition and content during seed development. Compared with the overall rate of TG accumulation, DGAT activity appeared coincidently with the onset of lipid accumulation at 26 DAP; the highest DGAT activity occurred during the rapid phase of lipid accumulation at 40 DAP; and a decline in DGAT activity coincided with a decline in the accumulation rate of TG after 40 DAP. The ricinoleate‐containing TG content was very low (only about 7%) in oil extracted from seeds before 19 DAP; however it increased up to about 77% of the oil at 26 DAP. The relative amount of triricinolein in oil at 26 DAP was 53 times higher than that at 19 DAP, and it was about 76% of the amount present in oil from mature castor seeds. The close correlation between profiles of RcDGAT activity and oil accumulation confirms the role of RcDGAT in castor oil biosynthesis.
Biomimetic oxidation of unactivated carbons in steroids by a model of cytochrome P‐450, oxorutheniumporphyrinate complex
Authors: Iida Takashi , Ogawa Shoujiro , Miyata Shouhei , Goto Takaaki , Mano Nariyasu , Goto Junichi , Nambara Toshio
Published: November 2006

Biomimetic oxidation of unactivated carbons for structurally different steroids was studied with a model of cytochrome P‐450, oxorutheniumporphyrinate complex, which is generatedin situby 2,6‐dichloropyridineN‐oxide as an oxygen donor and (5,10,15,20‐tetramesitylporphyrinate) ruthenium(II) carbonyl complex and HBr as catalysts. The O‐insertion positions depended significantly on specific structural features of the substrates to give novel and remote‐oxygenated steroids in one step. The electrophilic oxorutheniumporphyrinate attacked predominantly allylic and benzylic β‐carbons adjacent to a π‐bond and/or less hindered, electron‐richtert‐methine carbons in the substrates to give regio‐ and stereoselectively the corresponding oxo and/or hydroxy derivatives.
Interaction between ferric ions, phospholipid hydroperoxides, and the lipid phosphate moiety at physiological pH
Authors: Morrill Gene A. , Kostellow Adele , Resnick Lawrence M. , Gupta Raj K.
Published: November 2006

Iron‐catalyzed lipid peroxidation was examined using 1H NMR in a biphasic aqueous‐chloroform system. At physiological pH (7.4), mole ratios of phospholipids/Fe3+ as low as 1300∶1 catalyzed the rapid disappearance of endogenous lipid hydroperoxides with a loss of two of the four double bonds in PC containing palmitic (16∶0) and arachidonic (20∶4) acids in the sn‐1 and sn‐2 positions, respectively. The predominant phospholipid products after 1 h at 20°C were a 9‐carbon monounsaturated carbonyl and a phospholipid with an 11‐carbon Δ5,8 FA in the sn‐2 position. PC with linoleic acid (18∶2) in the sn‐2 position lost one double bond and formed a phospholipid with a 9‐carbon FA. Cardiolipin (linoleic acid‐rich) also lost about 40% of its double bonds. No detectable loss was seen for PC containing oleic acid (18∶1) or neutral lipids with PUFA. At arachidonyl PC/Fe3+ ratios less than 20∶1, significant broadening of the choline methyl proton peak was evident, indicating that Fe3+ may form a complex with the adjacent phosphate group and that the complex involves both the phosphate and the hydroperoxide adjacent to the Δ11 double bond. The results demonstrate that, at physiological pH, Fe3+‐catalyzed peroxidation in polyunsaturated phospholipids occurs selectively adjacent to specific double bonds (Δ9 or Δ11). These PC‐derived products have been shown to activate components of the inflammatory system. This suggests that the episodic release of ferric ions may play a significant role in generating inflammatory mediators.