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PubMed1991

Dietary alpha-linolenic acid is as effective as oleic acid and linoleic acid in lowering blood cholesterol in normolipidemic men.

The effect of dietary oleic acid (OA), linoleic acid (LA), and linolenic acid (LNA) on plasma lipid metabolism was studied in eight normolipidemic men. A mixed-fat diet composed of conventional foods was fed during 6-d pre- and post-experimental periods. The same basic diet but with 75% of the fat (26% of total energy) provided by sunflower and olive; canola; soybean; and sunflower, olive, and flax oils was fed during four 18-d experimental periods. Mean plasma total cholesterol (-18%), low-density-lipoprotein-cholesterol, (-22%) and very-low-density-lipoprotein-cholesterol (-41%) concentrations were significantly (P less than 0.004) lower after the experimental diets than after the mixed-fat diet. Mean serum apolipoprotein B (-19%) and apolipoprotein A-I (-9%) concentrations were also significantly (P less than 0.0007) lower after the experimental diets. The experimental diets were equally effective in lowering total and lipoprotein cholesterol and apolipoprotein concentrations in plasma, indicating that dietary OA, LA, and LNA were equally hypocholesterolemic.

Adult↗
PubMed2005

Comparative toxicity of oleic acid and linoleic acid on Raji cells.

OBJECTIVE: Parenteral diets are often administered to critically ill patients. To study one of the effects of commercially available parenteral lipid diets, rich in triacylglycerol esters of omega-6 polyunsaturated fatty acids or omega-9 monounsaturated fatty acids, on the immune system of such patients, we evaluated the cytotoxicity of oleic and linoleic acids on Raji cells that had been derived from human B-lymphocytes. METHODS: Cell death intensity and type were investigated by flow cytometry by quantitation of cell volume, granularity, DNA fragmentation, mitochondrial depolarization, and lipid accumulation. Fluorescence microscopy was used to determine chromatin condensation and type of cell death (acridine orange/ethidium bromide assay). Gene expression of BCL-XL, BCL-XS, C-MYC, and P53 was studied by reverse transcriptase polymerase chain reaction. RESULTS: Oleic acid was less toxic than linoleic acid to Raji cells. Both fatty acids promote apoptosis and necrosis of these cells. The mechanism of cell death induced by these fatty acids seemed to involve mitochondrial depolarization, lipid accumulation, and overexpression of C-MYC and P53. CONCLUSION: Oleic acid may offer a less harmful alternative to linoleic acid in parenteral diets with respect to patient B-lymphocyte-mediated immunologic activity.

Apoptosis↗
PubMedDate not supplied

Bioconversion of linoleic acid into conjugated linoleic acid by immobilized Lactobacillus reuteri.

Lactobacillus reuteri was immobilized on silica gel to evaluate the bioconversion of linoleic acid (LA) into conjugated linoleic acid (CLA), consisting of cis-9,trans-11 and trans-10,cis-12 isomers. The amount of cell to carrier, the reaction time, and the substrate concentration, pH, and temperature for CLA production were optimized at 10 mg of cells/(g of carrier), 1 h, 500 mg/L LA, 10.5, and 55 degrees C, respectively. In the presence of 1.0 mM Cu(2+), CLA production increased by 110%. Under the optimal conditions, the immobilized cells produced 175 mg/L CLA from 500 mg/L LA for 1 h with a productivity of 175 mg/(L.h) and accumulated 5.5 times more CLA than that obtained from bioconversion by free washed cells. The CLA-producing ability of reused cells was investigated over five reuse reactions and was maximal at pH 7.5, 25 degrees C, and 1.0 mM Cu(2+). The total amount of CLA by the combined five reuse reactions was 344 mg of CLA/L reaction volume. This was 8.6 times higher than the amount obtained from reuse reactions by free washed cells.

Bioreactors↗
PubMed2003

The effect of addition of linoleic acid on food intake regulation in linoleic acid tasters and linoleic acid non-tasters.

In a randomised, single blind, placebo-controlled crossover design study, we investigated whether healthy, non-smoking, dietary unrestrained women (n 24), divided into linoleic acid tasters (LAT, n 14) and linoleic acid non-tasters (LANT, n 10), differed in food intake regulation when linoleic acid was added to ice creams. The determination of subjects as LAT or LANT was done using a 10 microm-linoleic acid solution. The ice creams were characterised by the subjects and a taste perception test using the triangle test was conducted three times. Food intake and appetite were measured using the universal eating monitor. LAT and LANT did not differ in characterisation or in taste perception of the ice creams, even though LAT were able to increase their ability to discriminate between the ice cream with linoleic acid from the one containing oleic acid. No effect of LAT status or type of ice cream was found for hedonic value of the ice creams. Linoleic acid taster status did affect food intake regulation. For LAT, but not LANT, the amount eaten was a function of Deltasatiety. Subjects ate by weight of food and not by energy content. In conclusion, differences in food intake regulation were seen between LAT and LANT, in that the amount eaten by LAT was a function of Deltasatiety, but was not for LANT.

Adult↗
PubMed2006

Isolation of a novel strain of Butyrivibrio fibrisolvens that isomerizes linoleic acid to conjugated linoleic acid without hydrogenation, and its utilization as a probiotic for animals.

AIM: Isolation of a new strain of Butyrivibrio fibrisolvens possessing great capacity to produce conjugated linoleic acid (CLA) in order to utilize as a probiotic for animals. METHODS AND RESULTS: A novel strain (MDT-5) was isolated from the goat rumen, which exclusively converted linoleic acid (LA) to CLA, because of its high LA isomerase activity with virtually no CLA reductase activity. MDT-5 also converted linolenic acid to conjugated linolenic acid that may be more bioactive than CLA. The oral administration of MDT-5 every other day to mice for 2 weeks resulted in increased amounts of CLA in the contents of the large intestine (2.5-fold), as well as in adipose tissue (threefold). Feeding a high-LA diet, as well as prolonging the period of MDT-5 administration, further increased the CLA content in body fat. CONCLUSIONS: MDT-5 has by far greater ability to produce CLA than any other known bacteria. Administration of MDT-5 to mice increases CLA production in the large intestine, which results in increased CLA absorption. SIGNIFICANCE AND IMPACT OF THE STUDY: MDT-5 may be useful in pet animals as a probiotic to provide CLA continuously.

Adipose Tissue↗
PubMed2006

Effects of conjugated linoleic acid on linoleic and linolenic acid metabolism in man.

Evidence from animal studies suggests that conjugated linoleic acid (CLA) modulates plasma and tissue appearance of newly synthesized PUFA. The effects of a 1.2g (0.5 % energy) daily intake of the cis-9,trans-11 (c9,t11) isomer of CLA, trans-10,cis-12 (t10,c12) isomer of CLA or olive oil (placebo) on linoleic acid (LA) and linolenic acid (LNA) metabolism in healthy human volunteers was investigated. Fifteen subjects were fed an experimental diet and supplemented with c9,t11-CLA, t10,c12-CLA or placebo for 7 d before consuming a tracer dose of U-[(13)C]LA (50 mg) and U-[(13)C]LNA (50 mg). Blood samples were taken at 0, 2, 4, 6, 8, 24, 48, 72 and 168 h and analysed using high-precision MS. No differences between the groups in peak plasma [(13)C]LA (10.3-11.6 % of dose), [(13)C]LNA (2.5-2.9 % of dose), [(13)C]arachidonic acid (0.09-0.12 % of dose), [(13)C]EPA (0.04-0.06 % of dose) or [(13)C]DHA (0.06-0.10 % of dose) were detected. Concentration v. time curves (area under the curve) also showed no significant differences between groups. This suggests that, in healthy human subjects consuming a diet with adequate intake of essential fatty acids, CLA does not affect metabolism of LA or LNA.

Adolescent↗
PubMed2005

A new strain of Butyrivibrio fibrisolvens that has high ability to isomerize linoleic acid to conjugated linoleic acid.

A new strain of Butyrivibrio fibrisolvens (TH1) that has high potential to produce conjugated linoleic acid (CLA) was isolated. Strain TH1 had higher LA isomerase (LA-I) activity, and was much more tolerant to linoleic acid (LA) than other strains examined. However, high CLA reductase (CLA-R) activity resulted in the temporary accumulation of CLA and subsequent conversion to trans-vaccenic acid (t-VA). When LA was added to growing TH1 cultures in a solution with dimethylsulfoxide (LA/DMSO), CLA produced was greater than when LA was added in a mixture with bovine serum albumin (BSA). The number of viable cells decreased upon addition of LA/DMSO, but then increased as the CLA decreased upon its conversion to t-VA. This result suggests that B. fibrisolvens can resume growing by the removal of CLA from the cells. Most CLA was released from B. fibrisolvens cells by gentle washing with BSA, suggesting that CLA bound to the cells might be removed in the rumen and large intestine. Thus, CLA production by B. fibrisolvens in the digestive tract could be increased by a reduction in CLA-R activity without accompanying an overall decrease in the cell number of B. fibrisolvens. Fatty acids (FAs) with 18 carbon backbone inducted LA-I activity, whereas unsaturated FAs induced CLA-R activity, suggesting that FAs stimulate the synthesis of LA-I and CLA-R. Providing a diet with a low ratio of unsaturated to saturated FAs may favor CLA production.

Butyrivibrio↗
PubMed1993

Synthesis of monohydroxylated fatty acids from linoleic acid by rat aortic smooth muscle cells and tissues: influence on prostacyclin production.

We have investigated whether cellular metabolism of linoleic acid (18:2) can influence prostacyclin (PGI2) production by cultured rat aortic smooth muscle cells (SMC) and tissues. Incubation of rat SMC homogenates with [1-14C]18:2 results in the enzymatic synthesis of [14C]13-HODE (hydroxyoctadecadienoic acid) and to a lesser extent [14C]9-HODE as defined by gas-liquid chromatography-mass spectrometry (GLC-MS). The observed changes, in percent enzymatically synthesized 13-HODE in the presence of indomethacin, aspirin, metyrapone, 15-HPETE (hydroperoxyeicosatetraenoic acid), and NDGA, suggest that it is formed from the PGH (prostaglandin endoperoxide) synthase pathway. Incubation of intact adherent SMC with [14C]linoleic acid demonstrates that the monohydroxylated compounds are predominantly esterified within the membrane phospholipids and not released into the incubation medium. The simultaneous incubation or a short-term preincubation of 18:2 and arachidonic acid (20:4) do not modify the enzymatic profile of 20:4 transformation. By contrast, long-term preincubation of cells with 18:2 or 13-HODE stimulates the transformation of exogenously added [14C]20:4 to [14C]6-keto PGF1 alpha. However, exogenous 13-HODE does not enhance [14C]6-keto PGF1 alpha recovery from [14C]20:4 prelabeled SMCs. Our results demonstrate that 18:2 is a substrate for PGH-synthase in rat aortic SMC and tissues. The 13-HODE formed is essentially esterified in cell phospholipids and remains without any significant effects on the release of [14C]6-keto PGF1 alpha from [14C]20:4 prelabeled SMC.

Animals↗
PubMed1989

Bidirectional control of membrane expression and/or activation of the tumor cell IRGpIIb/IIIa receptor and tumor cell adhesion by lipoxygenase products of arachidonic acid and linoleic acid.

Lewis lung carcinoma cells express a plasma membrane receptor (i.e., IRGpIIb/IIIa) which is immunologically and functionally related to the platelet aggregation receptor complex (i.e., GpIIb/IIIa). Both fluorescence microscopy and flow cytometric analysis reveal that surface expression and/or activation of this tumor cell receptor is enhanced by a phorbol ester [i.e., 12-O-tetradecanoylphorbol-13-acetate (TPA)] and a lipoxygenase metabolite of arachidonic acid; 12-hydroxyeicosatetraenoic acid (i.e., 12-HETE). TPA-enhanced expression appears to be mediated by a lipoxygenase metabolite, as this effect can be reversed by lipoxygenase inhibitors but not by cyclooxygenase inhibitors. In parallel with these results both TPA and 12(S)-HETE [but not 12(R)-HETE] enhance tumor cell adhesion to endothelial cells, subendothelial matrix and fibronectin, but not to type IV collagen. TPA-enhanced adhesion can be reduced by lipoxygenase inhibitors but not by cyclooxygenase inhibitors and in addition, stimulated adhesion can be blocked by pretreatment of tumor cells with specific polyclonal or monoclonal antibodies which react against IRGpIIb/IIIa. 12(S)-HETE-enhanced adhesion can also be inhibited by these same antibodies. In contrast, a lipoxygenase product of linoleic acid, 13(S)-hydroxyoctadecadienoic acid, inhibited TPA and 12(S)-HETE-enhanced tumor cell adhesion to endothelial cells, subendothelial matrix, and fibronectin. These results suggest that (a) IRGpIIb/IIIa is a multifunctional receptor which mediates tumor cell adhesion to a variety of biological substrata, (b) TPA enhances surface expression and/or activation of this receptor possibly via a lipoxygenase metabolite of arachidonic acid, and (c) these effects are opposed by a lipoxygenase metabolite of linoleic acid.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1992

Effects of butylated hydroxyanisole on arachidonic acid and linoleic acid metabolism in relation to gastrointestinal cell proliferation in the rat.

In order to determine the effect of oral administration of 2(3)-tert-butyl-4-hydroxyanisole (BHA; dose-level: 1.5% BHA of the diet) on arachidonic acid (AA) and linoleic acid (LA) metabolism in correlation with changes in gastrointestinal cell kinetics, we coadministered two inhibitors of prostaglandin H synthase, acetylsalicylic acid (ASA) and indomethacin (IM), to rats. Coadministration of ASA (0.2%) and IM (0.002%) in the drinking water, resulted in a significant reduction of the BHA-induced enhancement of cell proliferation in forestomach and glandular stomach. ASA completely counteracted the effect of BHA on labeling indices in colon/rectum whereas IM exhibited no effect in this organ. Both inhibitors had no direct effect on cell kinetics in the control groups. ASA, and to a lesser degree IM, inhibited prostaglandin E2 release in all tissues examined. Whereas ASA did inhibit lipoxygenase-mediated metabolism of AA in forestomach tissue, ASA did not affect the release of AA- and LA-derived hydroxy fatty acids in glandular stomach and colon/rectum. IM did not affect lipoxygenase production. BHA, however, appeared to be a strong inhibitor of both routes of AA metabolism. While ASA nor IM affected LA metabolism, BHA inhibited both prostaglandin H synthase-mediated and lipoxygenase-mediated metabolism of AA and LA. A causal role of AA or LA metabolites in the process of cell proliferation enhancement induced by BHA, can therefore be excluded. Prostaglandin H synthase may, however, be involved in BHA activation by converting the hydroquinone metabolite of BHA to the corresponding quinone by redox cycling, which is probably accompanied by reactive intermediate production.

Animals↗
PubMed2006

Clostridium proteoclasticum: A ruminal bacterium that forms stearic acid from linoleic acid.

The aim of this study was to identify ruminal bacteria that form stearic acid (18 : 0) from linoleic acid (cis-9,cis-12-18 : 2). One 18 : 0-producing isolate, P-18, isolated from the sheep rumen was similar in morphology and metabolic properties to 'Fusocillus' spp. isolated many years ago. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequence (>1300 bp) analysis indicated that the stearate producer was most closely related to Clostridium proteoclasticum B316(T). Clostridium proteoclasticum B316(T) was also found to form 18 : 0, as were other bacteria isolated elsewhere, which occurred in the same family subclass of the low G+C% Gram-positive bacteria, related to Butyrivibrio fibrisolvens. These bacteria are not clostridia, and the ability to form 18 : 0 was present in all strains in contrast to proteolytic activity, which was variable. Production of 18 : 0 occurred in growing, but not in stationary-phase, bacteria, which made detection of biohydrogenating activity difficult, because of the inhibitory effects of linoleic acid on growth.

Animals↗
PubMed2004

Diversity of oleic acid, ricinoleic acid and linoleic acid conversions among Pseudomonas aeruginosa strains.

Sixteen Pseudomonas aeruginosa strains, including patent strain NRRL B-18602, three recent isolates from composted materials amended with ricinoleic acid, and 12 randomly selected from the holdings of the ARS Culture Collection, were examined for their fatty acid converting abilities. The study examined the bioconversion of oleic acid to 7,10-dihydroxy-8( E)-octadecenoic acid (DOD) and ricinoleic acid to 7,10,12-trihydroxy-8( E)-octadecenoic acid (TOD). A new DOD-like compound from linoleic acid was observed. All strains except NRRL B-247 exhibited varying levels of DOD production. NRRL B-1000, NRRL B-18602 and NRRL B-23258 with yields up to 84% were among the best DOD producers. TOD production generally paralleled DOD production at a relatively lower yield of up to 15%. Strains NRRL B-1000 and NRRL B-23260 were the best TOD producers. A DOD-like product in low yields was obtained from linoleic acid. The fatty acid bioconversion capability was related neither to growth rate nor to variation in the greenish pigmentation of the strains. Production of significant quantities of DOD and TOD from oleic and ricinoleic acids, respectively, appeared to be a characteristic trait of P. aeruginosa strains. A number of highly effective strains for DOD production were identified.

Culture Media↗
PubMed2003

Bioconversion of linoleic acid into conjugated linoleic acid during fermentation and by washed cells of Lactobacillus reuteri.

Conjugated linoleic acid (CLA) was produced at 300 mg l(-1) after 24 h culture of Lactobacillus reuteri in de Man-Rogosa-Sharpe medium containing 0.9 g linoleic acid (LA) l(-1) and 1.67% (v/v) Tween 80. CLA was mainly located in the extracellular space of the cells. Washed cells previously grown on LA were less active than unadapted washed cells in converting LA into CLA. Most of the CLA transformed by washed L. reuteri cells was located in cells or associated with cells. CLA production by washed L. reuteri cells was most efficient in conversion with 0.45 g LA l(-1) at pH 9.5 and 37 degrees C for 1 h.

Adaptation, Physiological↗
PubMed1982

Modulation of tissue prostaglandin synthesizing capacity by increased ratios of dietary alpha-linolenic acid to linoleic acid.

Semipurified diets containing ratios of alpha-linolenic acid (18:3 omega 3) to linoleic acid (18:2 omega 6) of 1/32, 1/7, 1/1, and 3.5/1 in the form of corn oil, soybean oil, soybean/linseed oil mix and linseed oil were fed to rats for 2 months. The first 3 diets were fed to another group of rats for 4 months and to a group through the second generation. Fatty acid analysis of liver and spleen ethanolamine glycerophosphatide revealed that, as the level of 18:3 omega 3 in the diet increased, the elongated, desaturated metabolites of the omega 6 series decreased and the omega 3 series increased. Noteworthy was the depression in the amount of the precursor of the 2-series prostaglandins (PG) as the omega 3 levels increased. Synthesis of PG by liver of rats fed 2 or 4 months markedly decreased, but at 2 months in thymus and spleen, it showed a trend toward decreasing only. Brain slices showed no decrease in PGF2 alpha synthesis after 4 months, but did decrease significantly after feeding the diets to the second generation. Synthesis of PGE2 by spleen homogenate from the second generation also significantly decreased. The replacement of omega 6 series fatty acids by omega 3 series is explained by the effective competition of 18:3 omega 3 over 18:2 omega 6 for the delta 6 desaturase. Depressions in PG synthesis by high dietary 18:3 omega 3 is explained by the competitive inhibition of the PG synthetase complex by 20:5 omega 3 as well as by the decreased levels of 20:4 omega 6.

Animals↗
PubMed1989

The suppression of eicosanoid synthesis by peritoneal macrophages is influenced by the ratio of dietary docosahexaenoic acid to linoleic acid.

The efficacy of docosahexaenoic acid (DHA) in suppressing eicosanoid synthesis by peritoneal macrophages in vivo was influenced by the relative amount of dietary DHA when linoleic acid (LA) was held constant. Increasing DHA from 0 to 37% of the fatty acids in diets containing 10 weight % fat (of which LA was 40%) caused an eleven-fold increase in the DHA content of macrophages. Limited retroconversion of DHA to eicosapentaenoic acid was observed. Macrophages in animals consuming DHA synthesized significantly lower amounts of leukotriene E4, prostaglandin E2 and 6-keto prostaglandin F1 alpha in vivo upon stimulation with zymosan. The maximum inhibition of eicosanoid synthesis was observed when the dietary DHA/LA ratio was 0.16 and no further inhibition occurred when the ratio was increased up to 0.81.

Animals↗
PubMed2006

Biocatalysis of linoleic acid to conjugated linoleic acid.

CLA refers to a group of geometrical and positional isomers of linoleic acid (LA) with conjugated double bonds. CLA has been reported to have diverse health benefits and biological properties. Traditional organic synthesis is highly capital-intensive and results in an isomeric mixture of CLA isomers. Biotechnology presents new alternatives to traditional lipid manufacturing methods. The objective of this study was to examine the effect of protein isolation procedures on linoleate isomerase (LAI) recovery from microbial cells and biocatalysis of LA to CLA. Protein isolation experiments were carried out using Lactobacillus acidophilus L1 and two strains of Lactobacillus reuteri (ATCC 23272 and ATCC 55739). Under the same assay conditions, ATCC 55739 had the highest LAI activity among the microbial cultures examined in this study. Efficiency of cell lysis methods, which included various combinations of lysozyme and mutanolysin treatments in combination with sonication and osmotic rupture of cells with liquid nitrogen, was very low. Although treatment of cell material with a detergent (octylthioglucoyranoside) freed a significant amount of LAI activity into the solution, it was not sufficient to recover all the LAI activity from the residual cells. Crude LAI preparations produced mainly the cis-9,trans-11 CLA isomer. Time and substrate/protein ratio had a significant effect on biocatalysis of LA to CLA. It appears that the mechanism and kinetics of enzymatic conversion of LA to CLA are quite complex and requires further research using pure LAI preparations.

Lactobacillus acidophilus↗
PubMed1980

Stereochemistry in the formation of 9-hydroxy-10,12-octadecadienoic acid and 13-hydroxy-9,11-octadecadienoic acid from linoleic acid by fatty acid cyclooxygenase.

9-Hydroxy-10,12-octadecadienoic acid and 13-hydroxy-9,11-octadecadienoic acid are formed from linoleic acid upon incubation with the microsomal fraction of homogenates of the sheep vesicular gland (Hamberg, M. and Samuelsson, B. (1967) J. Biol. Chem. 242, 5344-5354. This communication is concerned with the stereochemical aspects of the conversion. The ratio between the 9- and 13-hydroxy isomers was 77:23. Steric analysis of the individual isomers showed that the hydroxyl group of both isomers had mainly the L configuration, i.e. 9L:9D, 79:21 and 13L:13D, 9- and 13-hydroxyoctadecadienoates which had largely lost the tritium label (6% and 7% retention of tritium relative to precursor, respectively) showing that the hydrogen which is removed from C-11 during the conversion has the L (pro-S) configuration.

Animals↗
PubMed2001

Modulation of arachidonic acid distribution by conjugated linoleic acid isomers and linoleic acid in MCF-7 and SW480 cancer cells.

The relationship between growth and alterations in arachidonic acid (AA) metabolism in human breast (MCF-7) and colon (SW480) cancer cells was studied. Four different fatty acid preparations were evaluated: a mixture of conjugated linoleic acid (CLA) isomers (c9,t11, t10,c12, c11,t13, and minor amounts of other isomers), the pure c9,t11-CLA isomer, the pure t10,c12-CLA isomer, and linoleic acid (LA) (all at a lipid concentration of 16 microg/mL). 14C-AA uptake into the monoglyceride fraction of MCF-7 cells was significantly increased following 24 h incubation with the CLA mixture (P < 0.05) and c9,t11-CLA (P < 0.02). In contrast to the MCF-7 cells, 14C-AA uptake into the triglyceride fraction of the SW480 cells was increased while uptake into the phospholipids was reduced following treatment with the CLA mixture (P < 0.02) and c9,t11-CLA (P < 0.05). Distribution of 14C-AA among phospholipid classes was altered by CLA treatments in both cell lines. The c9,t11-CLA isomer decreased (P < 0.05) uptake of 14C-AA into phosphatidylcholine while increasing (P < 0.05) uptake into phosphatidylethanolamine in both cell lines. Both the CLA mixture and the t10,c12-CLA isomer increased (P < 0.01) uptake of 14C-AA into phosphatidylserine in the SW480 cells but had no effect on this phospholipid in the MCF-7 cells. Release of 14C-AA derivatives was not altered by CLA treatments but was increased (P < 0.05) by LA in the SW480 cell line. The CLA mixture of isomers and c9,t11-CLA isomer inhibited 14C-AA conversion to 14C-prostaglandin E2 (PGE2) by 20-30% (P < 0.05) while increasing 14C-PGF2alpha by 17-44% relative to controls in both cell lines. LA significantly (P < 0.05) increased 14C-PGD2 by 13-19% in both cell lines and increased 14C-PGE2 by 20% in the SW480 cell line only. LA significantly (P < 0.05) increased 5-hydroperoxyeicosatetraenoate by 27% in the MCF-7 cell line. Lipid peroxidation, as determined by increased levels of 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha), was observed following treatment with c9,t11-CLA isomer in both cell lines (P < 0.02) and with t10,c12-CLA isomer in the MCF-7 cell line only (P < 0.05). These data indicate that the growth-promoting effects of LA in the SW480 cell line may be associated with enhanced conversion of AA to PGE2 but that the growth-suppressing effects of CLA isomers in both cell lines may be due to changes in AA distribution among cellular lipids and an altered prostaglandin profile.

Arachidonic Acid↗