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PubMed1997

Low-dose eicosapentaenoic or docosahexaenoic acid administration modifies fatty acid composition and does not affect susceptibility to oxidative stress in rat erythrocytes and tissues.

In view of the promising future for use of n-3 polyunsaturated fatty acids (PUFA) in the prevention of cancer and cardiovascular diseases, it is necessary to ensure that their consumption does not result in detrimental oxidative effects. The aim of the present work was to test a hypothesis that low doses of eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) do not induce harmful modifications of oxidative cell metabolism, as modifications of membrane fatty acid composition occur. Wistar rats received by gavage oleic acid, EPA, or DHA (360 mg/kg body weight/day) for a period of 1 or 4 wk. Fatty acid composition and alpha-tocopherol content were determined for plasma, red blood cell (RBC) membranes, and liver, kidney, lung, and heart microsomal membranes. Susceptibility to oxidative stress induced by tert-butylhydroperoxide was measured in RBC. EPA treatment increased EPA and docosapentaenoic acid (DPA) content in plasma and in all the membranes studied. DHA treatment mainly increased DHA content. Both treatments decreased arachidonic acid content and n-6/n-3 PUFA ratio in the membranes, without modifying the Unsaturation Index. No changes in tissue alpha-tocopherol content and in RBC susceptibility to oxidative stress were induced by either EPA or DHA treatment. The data suggest that EPA and DHA treatments can substantially modify membrane fatty acids, without increasing susceptibility to oxidative stress, when administered at low doses. This opens the possibility for use of low doses of n-3 PUFA for chemoprevention without risk of detrimental secondary effects.

Animals↗
PubMed2004

Influences of fatty acid moiety and esterification of polyglycerol fatty acid esters on the crystallization of palm mid fraction in oil-in-water emulsion.

We examined the crystallization of palm mid fraction (PMF) in oil-in-water (O/W) emulsion, after adding polyglycerol fatty acid esters (PGFEs). We employed ultrasonic velocity measurements and DSC techniques, with special emphases on the influences of fatty acid moiety and esterification of PGFE. Twelve types of PGFEs were examined as additives. PGFEs have a large hydrophilic moiety composed of 10 glycerol molecules to which palmitic, stearic and behenic acids were esterified as the fatty acid moiety with different degrees of esterification. Crystallization temperature (T(c)) of PMF remarkably increased with increasing concentrations of the PGFEs as the chain length of the fatty acid moiety increased, and the PGFE became more hydrophobic in accordance with increasing degree of esterification. We observed that the heterogeneous nucleation of PMF in the O/W emulsion was activated at the oil-water interface, where the template effect of very hydrophobic long saturated fatty acid chains of the PGFE might play the main role of heterogeneous nucleation.

Crystallization↗
PubMed2000

Intestinal fatty acid binding protein may favor differential apical fatty acid binding in the intestine.

The intestinal mucosa metabolizes fatty acids differently when presented to the lumenal or basolateral membrane. Expression of both liver and intestinal fatty acid binding proteins (L- and I-FABPs) uniquely in the enterocyte offers a possible explanation of this phenomenon. An organ explant system was used to analyze the relative binding of fatty acids to each protein. More fatty acid was bound to L-FABP than to I-FABPs (28% vs. 6% of cytosolic radioactivity), no matter on which side the fatty acid was added. However, a 2-3-fold increase in fatty acid binding to the intestinal paralog was noted after apical addition of palmitic or oleic acid in mucosa from chow fed rats. When oleic acid was added apically, a 1.4-fold increase in binding to I-FABP was observed in mucosa derived from chronically fat fed rats, consistent with the previously observed 50% increase in the content of that protein. Immunocytochemical localization of both FABPs in vivo demonstrated an apical cytoplasmic localization in the fasting state, and redistribution to the entire cytoplasm after fat feeding. These data are consistent with the hypothesis that I-FABP may contribute to the metabolic compartmentalization of apically presented fatty acids in the intestine.

Animals↗
PubMed2003

Dietary conjugated linoleic acid differentially alters fatty acid composition and increases conjugated linoleic acid content in porcine adipose tissue.

Conjugated linoleic acids (CLA) have been shown to decrease body fat content in pigs. It is possible that feeding pigs diets rich in CLA may increase carcass lipid CLA to levels that could provide health benefits when included as a part of a healthy diet. Therefore, the aim of the present study was to determine whether dietary CLA supplementation has any effect on the fatty acid composition of subcutaneous and intramuscular adipose tissue in pigs. Thirty-five female cross bred (Large White x Landrace) pigs (initial weight 57.2 kg and initial P2 back fat 11.5 mm) were used in the present study. Pigs were housed individually and randomly allocated to one of six dietary treatments (0.00, 1.25, 2.50, 5.00, 7.50 and 10.00 g CLA55 (55 g CLA isomers/100 g total fatty acids; Natural Lipids Ltd, Hovdebygda, Norway)/kg) and fed their respective diets for 8 weeks. Twelve CLA isomers in the diet and in pig tissue lipids were separated by Ag+-HPLC. CLA was incorporated at fivefold higher levels in subcutaneous fat as compared with intramuscular fat and in a dose-dependant manner. Overall, the transfer efficiency of CLA was maximized at 5.00 g CLA55/kg. However, there was clear selectivity in the uptake or incorporation of cis,trans-9,11 isomer over the trans,cis-10,12 isomer. In general, CLA supplementation produced significant changes in skeletal muscle and adipose tissue fatty acid composition, indicating that dietary CLA had a potent affect on lipid transport and metabolism in vivo. Significant increases in myristic, palmitic and palmitoleic acids and a reduction in arachidonic acid were observed, suggesting an alteration in activity of delta5-, delta6- and delta9-desaturases in pig adipose tissue. In conclusion, feeding pigs diets supplemented with CLA increases carcass lipid CLA, but also results in changes in the fatty acid profile in pig fat that could potentially outweigh the benefits of CLA.

Adipose Tissue↗
PubMed2002

Chia seed (Salvia hispanica L.) as an omega-3 fatty acid source for broilers: influence on fatty acid composition, cholesterol and fat content of white and dark meats, growth performance, and sensory characteristics.

Five thousand four hundred, 1-d-old, male, Ross 308, broiler chicks were fed for 49 d to compare diets containing 10 and 20% chia (Salvia hispanica L.) seed to a control diet. Cholesterol content, total fat content, and fatty acid composition of white and dark meats were determined at the end of the trial. A taste panel assessed meat flavor and preference. Cholesterol content was not significantly different among treatments; however, the 10% chia diet produced a lower fat content in the dark meat than did the control diet. Palmitic fatty acid content was less in both meat types when chia was fed, with differences being significant (P < 0.05), except for the white meat and the 20% chia diet. alpha-Linolenic fatty acid was significantly higher (P < 0.05) in the white and dark meats with the chia diets. Chia significantly lowered the saturated fatty acid content as well as the saturated:polyunsaturated fatty acid and omega-6:omega-3 ratios of the white and dark meats compared to the control diet. No significant differences in flavor or preference ratings were detected among diets. Body weight and feed conversion were significantly lower with the chia diets than with the control, with weight reductions up to 6.2% recorded with the 20% chia diet.

Animal Feed↗
PubMed1984

In vivo stimulation of DNA synthesis and induction of ornithine decarboxylase in rat colon by fatty acid hydroperoxides, autoxidation products of unsaturated fatty acids.

The effect of intrarectal instillation of hydroperoxy and hydroxy fatty acids on colonic DNA synthesis and ornithine decarboxylase activity in male Sprague-Dawley rats was examined. A mixture of hydroperoxy-arachidonic acid isomers was prepared by methylene blue-sensitized photooxygenation. Pure 13-hydroperoxy-9,11-octadecadienoic acid was prepared by the action of soybean lipoxygenase on linoleic acid. Sodium borohydride reduction yielded the respective hydroxy fatty acids. Twelve hr after instillation of solutions of either hydroperoxy or hydroxy fatty acids, at concentrations up to 10 mM, DNA synthesis was increased in a dose-dependent fashion up to 240% above control values. The induction of ornithine decarboxylase occurred over a similar concentration range 3 hr after instillation of oxidized linoleic acid. In this case, the hydroxy acids (49-fold increase at 10 mM), were more stimulatory than the hydroperoxy derivatives (23-fold at 10 mM). Highly purified linoleic and arachidonic acids did not stimulate either activity at concentrations up to 50 mM. These data indicate that autoxidation products of unsaturated fatty acids, likely components of high-fat diets, can evoke proliferative responses in colonic mucosa. These responses may be relevant to the promotional effect of high dietary fat on colon carcinogenesis.

Animals↗
PubMed1976

Control of fatty-acid synthetase levels by exogeneous long-chain fatty acids in the yeasts Candida lipolytica and Saccharomyces cerevisiae.

Endogeneous fatty acid biosynthesis in the two yeast species, Saccharomyces cerevisiae and Candida lipolytica is completely repressed by the addition of long-chain fatty acids to the growth medium. In Candida lipolytica, this repression is accompanied by a corresponding loss of fatty acid synthetase activity in the cell homogenate, when the cells were grown on fatty acids as the sole carbon source. The activity of the Saccharomyces cerevisiae fatty acid synthetase, however, remains unaffected by the addition of fatty acids to a glucose-containing growth medium. From fatty-acid-grown Candida lipolytica cells no fatty acid synthetase complex can be isolated, nor is there any immunologically cross-reacting fatty acid synthetase protein detectable in the crude cell extract. From this it is concluded that Candida lipolytica, but not Saccharomyces cerevisiae, is able to adapt to the growth on fatty acids either by repression of fatty acid synthetase biosynthesis or by a fatty-acid-induced proteolytic degradation of the multienzyme complex. Similarly, the fatty acid synthetase complex disappears rapidly from stationary phase Candida lipolytica cells even after growth in fatty-acid-free medium. Finally, it was found that the fatty acid synthetase complexes from Saccharomyces cerevisiae and Candida lipolytica, though very similar in size and subunit composition, were immunologically different and had no common antigenic determinants.

Acetyl-CoA Carboxylase↗
PubMed1996

Essential fatty acid preparation reduces cholesterol and fatty acids in rat cortex.

Previous studies have shown that chronic administration of SR-3 (a 1:4 mixture of alpha-linolenic and linoleic acid) affects spatial learning, thermoregulation, pain threshold, and protection from seizures. The mode of action of SR-3 is unknown. One possible explanation is that SR-3 induces changes in the FA profile and in the cholesterol level in neuronal membranes. This study used 10 independent groups of rats (ni = 12) given 4 weeks of either saline, mineral oil (vehicle), alpha-tocopherol (antioxidant), alpha-linolenic acid, linoleic acid, or one of 5 different ratios of alpha-linolenic acid:linoleic acid (1:3, 1:4, 1:5, 1:6, 1:7) as free fatty acids. FA profile and cholesterol level were examined by GC method in synaptosomes obtained from the frontal cortex of the rats. The mineral oil treated group served as the control group. No difference was found in the FA profile or cholesterol level except for the SR-3 treated group. The ratio of 1:4 was found to have a significant influence on decreasing the cholesterol level and in inducing major changes in the FA profile, such as an increase in EFA. These effects of SR-3 may result in modification of the membrane fluidity, which may, in turn, enhance cognitive and neuropharmacological effects.

Animals↗
PubMed2004

Liver fatty acid binding protein expression enhances branched-chain fatty acid metabolism.

Although liver fatty acid binding protein (L-FABP) is known to enhance uptake and esterification of straight-chain fatty acids such as palmitic acid and oleic acid, its effects on oxidation and further metabolism of branched-chain fatty acids such as phytanic acid are not completely understood. The present data demonstrate for the first time that expression of L-FABP enhanced initial rate and average maximal oxidation of [2,3-3H] phytanic acid 3.5- and 1.5-fold, respectively. This enhancement was not due to increased [2,3-3H] phytanic acid uptake, which was only slightly stimulated (20%) in L-FABP expressing cells after 30 min. Similarly, L-FABP also enhanced the average maximal oxidation of [9,10-3H] palmitic acid 2.2-fold after incubation for 30 min. However, the stimulation of L-FABP on palmitic acid oxidation nearly paralleled its 3.3-fold enhancement of uptake. To determine effects of metabolism on fatty acid uptake, a non-metabolizable fluorescent saturated fatty acid, BODIPY-C16, was examined by laser scanning confocal microscopy (LSCM). L-FABP expression enhanced uptake of BODIPY-C16 1.7-fold demonstrating that L-FABP enhanced saturated fatty acid uptake independent of metabolism. Finally, L-FABP expression did not significantly alter [2,3-3H] phytanic acid esterification, but increased [9,10-3H] palmitic acid esterification 4.5-fold, primarily into phospholipids (3.7-fold) and neutral lipids (9-fold). In summary, L-FABP expression enhanced branched-chain phytanic acid oxidation much more than either its uptake or esterification. These data demonstrate a potential role for L-FABP in the peroxisomal oxidation of branched-chain fatty acids in intact cells.

Animals↗
PubMed1994

Regulation of fluorescent fatty acid transfer from adipocyte and heart fatty acid binding proteins by acceptor membrane lipid composition and structure.

Adipocyte and heart fatty acid binding proteins (A-FABP and H-FABP) are closely related members of the FABP family. Unlike the more distantly related liver FABP, these FABP have been proposed to transfer free fatty acids to model membranes by a collisional mechanism (Wootan, M. G., Bernlohr, D. A., and Storch, J. (1993) Biochemistry 32, 8622-8627; Kim, H. K., and Storch, J. (1992) J. Biol. Chem. 267, 20051-20056). Collisional transfer requires that the acceptor membranes interact with FABP during the transfer process. We, therefore, examined whether the acceptor membrane structure and lipid composition regulate the rate of anthroyloxy-labeled palmitate (2AP) transfer from A- and H-FABP, using a fluorescence resonance energy transfer assay. The results showed that 2AP transfer from A- and H-FABP was more rapid to acceptor vesicles containing acidic phospholipids and was slower to positively charged membranes. In addition, the rate of 2AP transfer from A- and H-FABP was enhanced by unsaturation of the phosphatidylcholine acyl chains and was slowed by the presence of cholesterol or sphingomyelin in the acceptor membranes. These latter changes were small but of a similar magnitude and together suggest that fatty acid transfer from A- and H-FABP was slower to membranes of greater lipid order. Since transfer by an aqueous diffusion mechanism would be unaffected by acceptor membrane properties, these studies strengthen the hypothesis that free fatty acid transfer from A- and H-FABP to membranes occurs via a collisional mechanism.

Adipocytes↗
PubMed2004

Effect of n-3 fatty acids on serum lipid levels and hepatic fatty acid metabolism in BALB/c.KOR-Apoeshl mice deficient in apolipoprotein E expression.

N-3 fatty acids exert a potent serum lipid-lowering effect in rodents mainly by affecting hepatic fatty acid oxidation and synthesis. However, it has been observed that fish oil and docosahexaenoic acid ethyl ester do not lower serum lipid levels in apolipoprotein E (apoE)-knockout (Apoetm1Unc) mice generated by gene targeting. To test the hypothesis that apoE expression is required for n-3 fatty acid-dependent regulation of serum lipid levels and hepatic fatty acid metabolism, we examined the effect of fish oil and n-3 fatty acid ethyl esters on the activity and gene expression of hepatic enzymes involved in fatty acid oxidation and synthesis using an alternative apoE-deficient mouse model with the BALB/c genetic background (BALB/c.KOR-Apoeshl). ApoE-deficient mice were fed diets containing 9.4% palm oil, fish oil, or 5.4% palm oil and 1% EPA plus 3% DHA ethyl esters for 15 days. In contrast to the reported data on apoE-knockout mice, fish oil and n-3 fatty acid ethyl esters greatly decreased serum triacylglycerol, cholesterol, and phospholipid levels in the Apoeshl mice. The decreases were greater with fish oil than with ethyl esters. The alterations by dietary n-3 fatty acids of serum lipid levels were accompanied by parallel changes in the activity and mRNA levels of enzymes involved in hepatic fatty acid oxidation and synthesis. The reason for the discrepancy between the results of the current study and previous studies is unknown. However, our study at least indicates that a lack of apoE expression does not necessarily accompany deficits in the n-3 fatty acid-dependent regulation of serum lipid levels and hepatic fatty acid metabolism.

Animals↗
PubMed2002

Long-chain polyunsaturated fatty acids in rat maternal milk, offspring brain and peripheral tissues in essential fatty acid deficiency.

Fatty acid status in humans is usually related to plasma or red blood cell fatty acid profiles. The aim of the study was to explore whether a maternal deficiency in dietary essential fatty acids would differentially affect lipid fractions in several tissues of the offspring, including brain. Female Wistar rats were fed an essential fatty acid-deficient diet during 3 months before mating. The fatty acid composition of different lipid fractions was examined in maternal milk, and in plasma, red blood cells, liver, adipose tissue, cerebral cortex and hippocampus of the offspring using thin layer and capillary column gas chromatography. Lipid fractions from most tissues of deprived offspring showed a common fatty acid profile characterized by elevated 20:3 omega9/20:4 omega6 ratio, and decreased docosahexaenoic acid and arachidonic acid. However, arachidonic acid was not affected in brain, even though 22:5 omega6 was increased in phospholipids of cerebral cortex and hippocampus. The present results demonstrate different degrees of resistance to essential fatty acid deficiency in lipid fractions and tissues. This suggests a priority distribution of arachidonic acid to preferential areas and shows that blood phospholipid fatty acids do not exactly reflect brain phospholipid status.

Adipose Tissue↗
PubMed2001

Dietary long-chain polyunsaturated fatty acids from different sources affect fat and fatty acid excretions in rats.

Several sources of long-chain polyunsaturated fatty acids (LCP) have been evaluated for infant-formula supplementation. These sources differ in their chemical structure [triglyceride (TG) or phospholipid (PL)], arrangement of fatty acids on the TG or PL backbone, fatty acid composition and presence of other lipid components. All of these characteristics influence fat digestion, may affect fat and fatty acid absorption, and hence, LCP bioavailability and metabolism in infancy. The main objective of this work was to establish the influence of different dietary LCP sources on overall fat and LCP absorption in early life. We compared fat and fatty acid excretions at weaning in rats fed control diets or diets supplemented with LCP as TG or PL. Two separate experiments were conducted. In Experiment 1, weanling rats were fed for 3 wk a control diet (C1), a diet with TG from tuna and fungal oils (TF-TG) or a diet with PL from pig brain concentrate (PB-PL). In Experiment 2, weanling rats were fed for 3 wk a control diet (C2), a diet containing egg-TG (EG-TG) or a diet containing egg-PL (EG-PL). Fat, mineral and saturated fatty acid excretions in feces were higher in rats fed PB-PL compared with those fed TF-TG diet. In Experiment 2, groups did not differ in fat and mineral excretions. However, the EG-PL group had lower fecal excretions of saturated fatty acids than the C2 and EG-TG groups. The 16:1(n-7), 18:1(n-9), 18:2(n-6) and 22:6(n-3) levels in feces were higher in the EG-TG group than in the EG-PL group. In summary, total fat and LCP excretions differed among rats fed diets supplemented with LCP from different sources.

Absorption↗
PubMed1974

Inhibition of ileal water absorption by intraluminal fatty acids. Influence of chain length, hydroxylation, and conjugation of fatty acids.

The influence of fatty acids on ileal absorption of water, electrolytes, glucose, and taurocholate was examined in Thirty-Vella fistulas in five mongrel dogs. Fatty acid absorption also was measured. Segments of terminal ileum were perfused at steady state with isotonic electrolyte solutions containing 11.2 mM glucose, 4.5 mM taurocholate, and 0.1-5.0 mM fatty acid. Three C(18) fatty acids, oleic acid, 10(9)-hydroxystearic acid, and ricinoleic acid, completely inhibited water absorption at 5 mM. Sodium, chloride, and potassium absorptions were inhibited in parallel with absorption of water. Differences between the potencies of C(18) fatty acids were apparent when lesser concentrations were perfused. Dodecanoic and decanoic acids were as effective as C(18) fatty acids at 5 mM but octanoic and hexanoic acids were ineffective. The polar group of C(18) fatty acids was modified by conjugating oleic and ricinoleic acids with taurine. When these compounds and a substituted C(18) fatty acid, p-n-decylbenzenesulfonate, were perfused, water absorption was also inhibited. Short-chain fatty acids (C(3) and C(4)) and their hydroxylated derivatives were ineffective at 5 mM. When water absorption was inhibited, absorption of glucose and taurocholate was decreased. We speculate that the phenomenon of inhibition of water and electrolyte absorption by fatty acids may be relevant to steatorrhea and diarrhea in man.

Animals↗
PubMed1999

Intake of fatty acids in western Europe with emphasis on trans fatty acids: the TRANSFAIR Study.

OBJECTIVE: To assess the intake of trans fatty acids (TFA) and other fatty acids in 14 Western European countries. DESIGN AND SUBJECTS: A maximum of 100 foods per country were sampled and centrally analysed. Each country calculated the intake of individual trans and other fatty acids, clusters of fatty acids and total fat in adults and/or the total population using the best available national food consumption data set. RESULTS: A wide variation was observed in the intake of total fat and (clusters) of fatty acids in absolute amounts. The variation in proportion of energy derived from total fat and from clusters of fatty acids was less. Only in Finland, Italy, Norway and Portugal total fat did provide on average less than 35% of energy intake. Saturated fatty acids (SFA) provided on average between 10% and 19% of total energy intake, with the lowest contribution in most Mediterranean countries. TFA intake ranged from 0.5% (Greece, Italy) to 2.1% (Iceland) of energy intake among men and from 0.8% (Greece) to 1.9% among women (Iceland) (1.2-6.7 g/d and 1.7-4.1 g/d, respectively). The TFA intake was lowest in Mediterranean countries (0.5-0.8 en%) but was also below 1% of energy in Finland and Germany. Moderate intakes were seen in Belgium, The Netherlands, Norway and UK and highest intake in Iceland. Trans isomers of C18:1 were the most TFA in the diet. Monounsaturated fatty acids contributed 9-12% of mean daily energy intake (except for Greece, nearly 18%) and polyunsaturated fatty acids 3-7%. CONCLUSION: The current intake of TFA in most Western European countries does not appear to be a reason for major concern. In several countries a considerable proportion of energy was derived from SFA. It would therefore be prudent to reduce intake of all cholesterol-raising fatty acids, TFA included.

Adult↗
PubMed1998

Effects of dietary polyunsaturated fatty acids on rat brain plasma membrane fatty acid composition.

The effects of four different diets on phospholipid fatty acid composition of rat brain plasma membranes were evaluated. Rats were given a semisynthetic diet in which lipids were supplied by 5% peanut oil (n-3 PUFA deficient diet), cod liver oil (n-6 PUFA deficient diet), partially hydrogenated palm oil (total PUFA deficient diet) or a mixture of peanut and rapeseed oil (control group). Animals fed the total PUFA deficient diet had significantly lower body and brain weights than the control group (p < 0.05). Lower brain cholesterol and phospholipids also were observed in animals fed the total PUFA deficient diet, whereas the brain of animals fed the n-6 PUFA deficient diet had higher levels of these lipid components than the control group (p < 0.05). Phosphatidylcholine and phosphatidylethanolamine were mutually replaced in animals fed the n-6 and n-3 PUFA deficient diets, so that the sum of these two membrane constituents was maintained around 77% of total phospholipids. Brain phospholipid fatty acid composition was significantly modified by the diets studied. Thus, despite being a highly protected organ, the fatty acid composition of the brain can be extensively modulated by dietary lipids.

Animals↗