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Interesterification (acidolysis) of butterfat with conjugated linoleic acid in a batch reactor.

Six commercial lipases, in free or immobilized form, were tested for their ability to catalyze acyl exchange between conjugated linoleic acid and anhydrous butterfat under solvent-free conditions. Immobilized Candida antarctica lipase exhibited the best activity. Experiments were conducted for this lipase in butterfat to conjugated linoleic acid ratios of 10:1 (vol/vol), temperatures from 30 to 70 degrees C, enzyme concentrations of 50 to 200 mg/g of reaction mixture, and water contents of 0.15 to 2% (wt/wt). At the maximum enzyme concentration used, equilibrium was reached within the first 24 h of reaction. The optimum temperature was 50 degrees C. The triacylglycerol profile of the product butterfat reflected changes in the relative proportions of fatty acid residues as the reaction proceeded, with increases in those triacylglycerols containing 46 to 54 carbon atoms and concomitant decreases in those triacylglycerols containing 34 to 42 carbon atoms.

Butter↗

Dietary conjugated linoleic acid alleviates nonalcoholic fatty liver disease in Zucker (fa/fa) rats.

Nonalcoholic fatty liver disease (NAFLD) is the preferred term to describe the spectrum of liver damage ranging from hepatic steatosis to steatohepatitis, liver fibrosis, and cirrhosis, and it is emerging as the most common liver disease in industrialized countries. Thus, the discovery of food components that would ameliorate NAFLD is of interest. Conjugated linoleic acid (CLA), a mixture of positional and geometric isomers of linoleic acid, has attracted considerable attention because of its potentially beneficial biological effects both in vitro and in vivo. We tested whether dietary CLA protects Zucker (fa/fa) rats from hepatic injury. After 8 wk of feeding, hepatomegaly, hepatic triglyceride (TG) accumulation, and elevated hepatic injury markers in plasma were markedly alleviated in CLA-fed Zucker rats compared with linoleic acid-fed (control) rats. These effects were attributed in part to the enhanced hepatic activities of carnitine palmitoyltransferase, a key enzyme of fatty acid beta-oxidation, and microsomal TG transfer protein, an important factor for lipoprotein secretion due to the CLA diet. We previously reported that the severe hyperinsulinemia in control Zucker rats was attenuated in CLA-fed rats due to an enhanced level of plasma adiponectin, which improves insulin sensitivity. In the present study, the adiponectin concentration was increased and the mRNA expression of tumor necrosis factor-alpha, an inflammatory cytokine, was markedly suppressed in the liver of CLA-fed Zucker rats. We speculate that the enhanced level of liver adiponectin may prevent the development and progression of NAFLD in CLA-fed Zucker rats.

Adiponectin↗

Effect of dietary depletion and repletion of linoleic acid on renal fatty acid composition and urinary prostaglandin excretion.

To study the effect of dietary modification on urinary prostaglandin E (UPGE) excretion and on renal fatty acid compositions, weanling male rats were raised on a fat-free diet for 6 weeks and were switched to a diet containing 2 energy % of linoleic acid (LA) for 8 days. During fat deprivation, UPGE excretion increased in the first week (6.9 ng/24 hours urine), fell to a minimum of 1.1 ng/24 hours at 3rd week and thereafter remained at a level lower than that in the controls (3.1 ng/24 hours). UPGE excretion returned rapidly to normal (2.7 ng/hr) only 24 hours after LA supplementation. During LA treatment, arachidonic acid (AA) concentrations in renal cholesteryl esters rapidly increased from 19% to 27% (33% in the controls), while concentrations in renal phospholipids (PL) and renal free fatty acids (FFA) did not change during the first four days but reached the normal range at the 8th day. The present studies demonstrate that chronically fat deficient animals excreted significantly less UPGE than that in the controls. However, this deficiency could be rapidly reversed by LA supplementation despite the fact that AA levels in renal lipid fractions remained well below normal. This suggests that dietary LA may be rapidly converted to AA and subsequently to PGE without AA levels rising in the lipid fractions usually thought of as being PG precursors.

Animals↗

Effect of phosphatidylethanolamine and its constituent base on the metabolism of linoleic acid in rat liver.

Dietary phosphatidylethanolamine (PE) contributes the circulatory and hepatic free-ethanolamine in rats (Ikeda et al. (1987) Biochim. Biophys. Acta 921, 245). A role for circulatory ethanolamine has not been defined; however, our recent studies have shown that exogenous ethanolamine influences cholesterol and linoleic acid metabolism in rats (Imaizumi et al. (1983) J. Nutr. 113, 2403). In order to understand the role of dietary PE the effects of PE and its base on the hepatic metabolism of linoleic acid were investigated in vivo and in primary cultured hepatocytes in rats. Dietary PE increased the plasmic level of ethanolamine from 37 to 52 microM and decreased the ratio of arachidonate to linoleate in hepatic phospholipids. Activity of hepatic delta 6-desaturase decreased in rats given PE and the desaturation of [14C]linoleate in the cultured hepatocytes decreased by the addition of ethanolamine. Secretion [14C]linoleate labeled very-low-density lipoprotein from the cultured hepatocytes decreased by the addition of ethanolamine. Dietary PE caused an increased formation of CO2 from [14C]acetate by liver slices, and ethanolamine added to the hepatocytes caused an increased oxidation of [14C]linoleate and a suppression of fatty acid synthesis from [3H]serine. These results suggest that ethanolamine derived from the dietary PE plays a regulatory role in the linoleate metabolism in the liver.

Animals↗

Effect of soy protein isolate and conjugated linoleic acid on the growth of Dunning R-3327-AT-1 rat prostate tumors.

BACKGROUND: Epidemiologic and animal model studies suggest that consumption of soy isoflavones may be associated with reduced risk of prostate cancer (PC). In addition, animal model studies suggest that conjugated linoleic acid (CLA), a natural positional isomer of linoleic acid, inhibits tumor growth in various models, including models of PC. METHODS: Based on the above-mentioned data, the objective of the present study was to test the hypothesis that supplementation of the diet with combinations of isoflavone-rich soy protein isolate and CLA would act to inhibit the growth of androgen-independent R-3327-AT-1 rat prostate tumor cells inoculated ectopically into male Copenhagen rats. RESULTS: The results of this study indicate that neither an isoflavone-rich soy protein isolate (SPI), nor CLA inhibit the in vivo growth and development of prostate tumor cells when administered in the diet either singly or in combination. Moreover, at the highest concentrations SPI and CLA (i.e., 20% SPI, 1% CLA), there was a statistically significant increase in tumors volume over controls. Administration of SPI at 10% in the diet also enhanced tumor growth, whereas at 5%, SPI exerted no measurable effect. CLA administration alone had no observable effects on AT-1 tumor growth. CONCLUSION: These results, in an established rat model, suggest caution in using isoflavone-rich SPI in human studies involving advanced hormone-refractory prostate cancer until further investigation of these effects are completed.

Animals↗

Parenteral nutrition providing a restricted amount of linoleic acid in severely burned patients: a randomised double-blind study of an olive oil-based lipid emulsion v. medium/long-chain triacylglycerols.

It has been claimed that lipid emulsions with a restricted linoleic acid content can improve the safety of total parenteral nutrition (TPN). The tolerability of TPN and its effects on the metabolism of fatty acids were assessed in this prospective, double-blind, randomised study comparing an olive/soyabean oil long-chain triacylglycerol (LCT) with a medium-chain triacylglycerol (MCT)/LCT; 50:50 (w) based lipid emulsion in two groups (O and M, respectively; eleven per group) of severely burned patients. After resuscitation (48-72 h), patients received TPN providing 147 kJ/kg per d (35 kcal/kg per d) with fat (1.3 g/kg per d) for 6 d Plasma fatty acids, laboratory parameters including liver function tests, and plasma cytokines were assessed before and after TPN. Adverse events encountered during TPN and the clinical outcomes of patients within the subsequent 6 months were recorded. With both lipid emulsions, the conversion of linoleic acid in its higher derivatives (di-homo-gamma-linolenic acid) improved and essential fatty acid deficiency did not appear. Abnormalities of liver function tests occurred more frequently in the M (nine) than in the O (three) group (P = 0.04, Suissa-Shuster test). Seven patients (four from group O and three from group M) died as a consequence of severe sepsis 3-37 d after completion of the 6 d TPN period. When compared with the surviving patients, those who died were older (P = 0.01) and hyperglycaemic at baseline (P < 0.001), and their plasma IL-6 levels continued to increase (P < 0.04). Although fatty acid metabolism and TPN tolerability were similar with both lipid emulsions, the preservation of liver function noted with the use of the olive oil-based lipid emulsions deserves confirmation.

Adult↗

Tensile properties and water absorption of zein sheets plasticized with oleic and linoleic acids.

Corn zein has been investigated for fabrication of biodegradable packaging materials. Our objective was to investigate the effect of added plasticizers, oleic and linoleic acids, on tensile properties and water absorption of zein sheets. Moldable resins were precipitated from aqueous ethanol dispersions of zein and fatty acids and rolled into sheets of approximately 0.5 mm in thickness. To increase plasticization effects, zein-oleic acid sheets were replasticized by heating them in fatty acid baths. Plasticization resulted in flexible sheets of high clarity, low modulus, and high elongation and toughness, although low tensile strength. Water absorption of zein sheets was lowered by plasticization, attributed in part to reduced mass fraction of zein. Polymerization of linoleic acid may have sealed off pores on sheet surfaces, thus slowing water absorption.

Absorption↗

Distribution of milk fat globules in cow's milk high in linoleic acid.

The influence of feeding cows formaldehyde-treated polyunsaturated oilseed supplement on fatty acid composition and distribution of particle size of milk fat globules has been studied. Supplement increased linoleic acid in milk fat from 1.7 to 27.4%. Distributions of particle size measured by a Coulter counter showed that milk fat from cows receiving supplement had large milk fat globules than those in milk fat of the same cows when supplementation was discontinued. However. this difference in size could not be attributed to percent linoleic acid in the milk fat since correction of the data of supplemented cows for percent milk fat and size of milk fat globules resulted in particle distributions strikingly similar in shape.

Animals↗

Inhibition of glutathione S-transferase P type-positive foci development by linolic acid hydroperoxides and their secondary oxidative products in a rat in vivo mid-term test for liver carcinogens.

The effects of linolic acid hydroperoxides (product A) and secondary oxidative products of product A (product B), were examined in an in vivo mid-term test for hepatocarcinogens or hepatopromoters in rats. The number of placental type of glutathione S-transferase (GST-P)-positive foci of the liver was significantly reduced in rats given diethylnitrosamine (DEN) followed by products A (4.64 +/- 1.09, P less than 0.05) or B (3.62 +/- 1.65, P less than 0.01) as compared to the controls given carcinogen alone (6.31 +/- 2.82). The area of GST-P positive foci was also significantly reduced in rats given DEN followed by product B (0.30 +/- 0.21, P less than 0.05) as compared to the controls (0.47 +/- 0.23). These results suggest that linolic acid hydroperoxides or their secondary oxidative products are not hepatocarcinogens and rather may possess inhibitory potential for liver carcinogenesis.

Animals↗

Effect of autoxidized linoleic acid on the contents of cytochrome P-450 and cytochrome b5, and drug-metabolizing enzyme activities in rat liver.

Autoxidized linoleic acid (AL) having 800 meq/kg of peroxide value and 1,700 meq/kg of carbonyl value was given in repeated oral doses for 1-15 days at a daily dose of 2.5 ml/kg to male Wistar rats. During the administration, the effect of AL on drug-metabolizing activity was investigated periodically in liver microsomes. The contents of cytochrome P-450 and b5 were increased by consecutive oral doses for 3-7 days. Thereafter, the amount of cytochrome P-450 decreased gradually, but the b5 decreased slightly. Thus, after administration for 11-15 days, the cytochrome P-450 content was significantly lower but the cytochrome b5 content was rather high in comparison with the control group. The aminopyrine-N-demethylase activity was not reduced even after repeated oral doses of AL for 15 days. The activation of 2-acetyl amino fluorene (2-AAF), which the authors termed S-9 activity, gradually decreased during administration for more than 3 days, and completely disappeared after administration for 9 days.

2-Acetylaminofluorene↗

Inhibitory effects of c9, t11-conjugated linoleic acid on invasion of human gastric carcinoma cell line SGC-7901.

AIM: To investigate the effect of c9, t11-conjugated linoleic acid (c9, t11-CLA) on the invasion of human gastric carcinoma cell line and its possible mechanism of preventing metastasis. METHODS: Using reconstituted basement membrane invasion, chemotaxis, adhesion, PAGE substrate zymography and RT-PCR assays, we analyzed the abilities of invasion, direct migration, adhesion of intracellular matrix, as well as the activity of type IV collagenase and expression of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 mRNA in SGC-7901 cells which were treated with gradually increased concentrations (25, 50, 100 and 200 micromol/L) of c9, t11-CLA for 24 h. RESULTS: At the concentrations of 200 micromol/L, 100 micromol/L and 50 micromol/L, c9,t11-CLA suppressed the invasion of SGC-7901 cells into the reconstituted basement membrane by 53.7 %, 40.9 % and 29.3 %, respectively, in comparison with the negative control. Only in the 200 micromol/L c9,t11-CLA group, the chemotaxis of SGC-7901 cells was inhibited by 16.0 % in comparison with the negative control. C9,t11-CLA also could inhibit the adhesion of SGC-7901 cells to laminin, fibronectin and Matrigel, increase the expression of TIMP-1 and TIMP-2 mRNA, and reduce type IV collagenase activities in the serum-free medium supernatant of SGC-7901 cells. CONCLUSION: c9,t11-CLA can inhibit the invasion of SGC-7901 cells at multiple procedures in tumor metastasis cascade, which may be associated with the induction of TIMP-1 and TIMP-2 mRNA expression.

Adenocarcinoma↗

Conjugated linoleic acid suppresses triglyceride accumulation and induces apoptosis in 3T3-L1 preadipocytes.

Four sets of experiments were conducted to examine the influence of conjugated linoleic acid (CLA) isomers during proliferation and differentiation of cultures of 3T3-L1 preadipocytes using physiological culturing conditions. Cultures treated with either albumin [bovine serum albumin (BSA) vehicle] or linoleic acid (LA) served as controls. For the proliferation study (Expt.1), cells were cultured in media containing a crude mixture of CLA isomers or pure LA at 0, 10, 50, or 200 microM for 4 d. Preadipocyte proliferation (cell number, 3H-thymidine incorporation into DNA) decreased as the level of CLA increased in the cultures. In contrast, LA had no impact on DNA synthesis. In Experiment 2a, postconfluent cultures were grown in media containing a crude mixture of CLA isomers or LA at 0, 10, 50, or 200 microM for the next 6 d. Postconfluent cultures supplemented with 50-200 microM CLA had less triglyceride (TG) and were smaller in size than cultures supplemented with similar amounts of LA. In Experiment 2b, postconfluent cultures supplemented with 200 microM of a crude mixture of CLA isomers or LA were harvested on days 1, 3, 6, or 9. Differences in TG content of cultures supplemented with 200 microM CLA compared to control and LA-supplemented cultures became apparent after 3 d of culture. Experiments 3a and 3b examined whether the fatty acid vehicle (BSA vs. ethanol) or the vitamin E status (+/-0.2 mM alpha-tocopherol) of the cultures altered CLA's impact on preadipocyte TG content. In Experiment 3a, ethanol-treated cultures had more TG than non-ethanol-treated cultures regardless of the fatty acid treatment. In Experiment 3b, cultures treated with 100 microM of either a crude mixture of CLA or the trans-10,cis-12 CLA isomer without supplemental vitamin E for 6 d had less TG than CLA-treated cultures containing vitamin E. In Experiment 4, postconfluent cultures were grown in media containing 100 microM LA or either a crude mixture of CLA isomers or the trans-10,cis-12 CLA isomer for 24-96 h to assess CLA's influence on the cell cycle and indices of apoptosis. Cultures treated with 100 microM CLA for 24-96 h had more apoptotic cells than BSA- or LA-treated cultures. Furthermore, cultures treated for 48 h with CLA had fewer cells in the S-phase than control cultures. The effects of the trans-10,cis-12 CLA isomer were more pronounced than those of the crude mixture of CLA isomers. These data suggest that CLA may exert its antiobesity effects by inhibiting proliferation, attenuating TG content, and/or inducing apoptosis in (pre)adipocytes.

3T3 Cells↗

Fetal growth is associated positively with maternal intake of riboflavin and negatively with maternal intake of linoleic acid.

OBJECTIVE: To examine whether dietary factors in pregnancy are related to fetal growth. DESIGN: Prospective longitudinal study during pregnancy; midway through gestation a dietary history was obtained. SUBJECTS/SETTING: Subjects (n = 372) were participants in a study on maternal essential fatty acid status during pregnancy who did not have hypertension or any metabolic, cardiovascular, neurological, or renal disorder. Only pregnant white women with the intention to give birth in one of the three hospitals involved in the study were included. All three hospitals were located in the southern part of the Netherlands. STATISTICAL ANALYSES PERFORMED: The relation between maternal nutrition and fetal growth was evaluated using multiple regression analyses. RESULTS: Maternal intake of n-3 fatty acids plus arachidonic acid and of riboflavin were associated positively with fetal growth. A negative relation was observed between linoleic acid intake and fetal growth. APPLICATIONS/CONCLUSIONS: Our data suggest that the maternal diet during pregnancy is associated with fetal growth. Although this relationship ought to be more closely investigated, our results imply that much more attention should be paid to an adequate maternal diet during pregnancy, especially with respect to riboflavin and fatty acid intake.

Adolescent↗

Down-regulation of PPARgamma2-induced adipogenesis by PEGylated conjugated linoleic acid as the pro-drug: Attenuation of lipid accumulation and reduction of apoptosis.

This study is designed to evaluate whether the PEGylated conjugated linoleic acid (PCLA) as the pro-drug can have favorable stability, bioavailability, and anti-adipogenic activity in 3T3-L1 cells for anti-obesity when compared with conjugated linoleic acid (CLA) itself. The CLA was simply coupled to poly(ethylene glycol) (PEG) at the melting state without solvents or catalysts through ester linkages between the carboxylic group of CLA and the hydroxyl group of PEG. To confirm of PCLA as the pro-drug, CLA release from PCLA was investigated by using high-performance liquid chromatographic (HPLC), showing that CLA release from PCLA was almost 90% in a nearly continuous fashion over the next 75h. Apoptosis was promoted by both CLA- and PCLA-treatments with increasing concentrations. However, the level of cell apoptosis induced by PCLA was lower than that induced by CLA owing to the biocompatible and hydrophilic properties of PEG. Moreover, the PCLA decreased glycerol-3-phosphate dehydrogenase (GPDH) activity in 3T3-L1 cells by acting upon major adipocyte marker proteins such as PPARgamma2, C/EBPalpha, and aP2 modulators. Furthermore, either CLA or PCLA stimulated basal, but not isoproterenol-sensitive, lipolysis in our cell model, suggesting that both CLA and PCLA may stimulate lipolysis via hormone sensitive lipase (HSL)-independent mechanisms. These results suggest that the PCLA may prove to be a stable pro-drug to control the deposition of fat in the human body, and that the anti-adipogenic effect of the PCLA on 3T3-L1 cells will offer a challenging approach for anti-obesity.

3T3-L1 Cells↗

Effectiveness of short-term feeding strategies for altering conjugated linoleic acid content of beef.

A steer finishing trial was performed to determine the effect of short-term dietary regimens on conjugated linoleic acid (CLA) content of muscle tissues. The experimental design was an incomplete 3 x 2 factorial, with three levels of soybean oil (SBO; 0, 4, and 8% of diet DM) and two levels of forage (20 vs. 40% of diet DM). Forty Angus x Hereford steers averaging 504 +/- 29.0 kg were allotted randomly to one of four treatments for the last 6 wk of the finishing period. Treatments were: 80:20 concentrate:forage control diet (C); 80:20 concentrate:forage + 4% SBO (C4); 60:40 concentrate:forage + 4% SBO (F4); and 60:40 concentrate:forage + 8% SBO (F8). After 42 d on the experimental diets, steers were sacrificed and samples were collected from the chuck, loin, and round muscle groups. Fatty acid (FA; mg/100 mg of FA) composition was determined by gas-liquid chromatography. Data were statistically analyzed with mixed models procedures. The performance and carcass quality model included the effects of SBO and forage. The model for FA composition included the effects of SBO, forage, muscle group, and interactions. Orthogonal contrasts were used to determine linear effects of SBO. There were no differences in growth performance among treatments (P > 0.05). Increasing dietary SBO linearly decreased dressing percent (P = 0.04), and tended to linearly decrease marbling score (P = 0.12) and quality grade (P = 0.08). The only CLA isomer detected in tissue samples was cis-9,trans-11. Addition of SBO to diets linearly increased linoleic acid (18:2n-6; P = 0.04) and tended to linearly increase linolenic acid (18:3n-3; P = 0.10) in muscle tissues. The CLA in lean tissues was decreased (P = 0.005) with SBO-containing diets. These findings suggest that increased PUFA may limit ruminal production of CLA and trans-vaccenic acid (VA) and/or may depress stearoyl-CoA desaturase expression or activity in lean tissues, which in turn limits CLA formation and accretion in tissues. Increasing dietary forage tended to increase 18:0, 18:2n-6, CLA, and 18:3n-3 (P < 0.15), suggesting that increased forage may mitigate toxic effects of PUFA on ruminal biohydrogenation, thereby increasing the pool of CLA and VA available for CLA formation and accretion in tissues. Short-term feeding of elevated SBO and forage levels can alter FA profiles in muscle tissues.

Animal Feed↗

Inhibitions of the autoxidation of linoleic acid by flavonoids in micelles.

The activities of five flavonoids as chain-breaking antioxidants have been studied for the autoxidation of linoleic acid in cetyl trimethylammonium bromide (CTAB) micelles at 37 degrees C. Flavonols such as quercetin, rutin and morin exhibited antioxidant activities, while two flavanones, naringin and hesperidin, did not suppress the oxidation appreciably. The ratio of rate constants for inhibition and propagation kinh/kp and stoichiometric factor n were determined.

Antioxidants↗

Effects of conjugated linoleic acid on oxygen diffusion-concentration product and depletion in membranes by using electron spin resonance spin-label oximetry.

The effect of conjugated linoleic acid (CLA) on the relation between structure and function of membranes is described in this paper. Electron spin resonance (ESR) spin-label oximetry was used in the present study to evaluate if oxygen transport and oxygen depletion were affected by incorporation of CLA instead of linoleic acid into membrane phospholipids. Specifically, 1-stearoyl-2-(9cis, 11 trans-octadecadienoyl)-phosphorylcholine (SCLAPC) was incorporated into soy plant phosphatidylcholine (soy PC) or egg yolk PC (EYPC) bilayers. The use of spin labels attached to different carbons along the fatty acid chain makes it possible to carry out structural and oximetric determinations with the same test sample. For example, the incorporation of 5 mol% SCLAPC increased the oxygen diffusion-concentration product in soy PC or EYPC liposomes at 37 degrees C, slightly decreased the ordering of the hydrocarbon chains at the C10 and C12 positions (in the region of the conjugated double bonds), and increased the rate of oxygen depletion from the aqueous medium. Similar results were not obtained by incorporating 5 mol% of 1-stearoyl-2-linoleoyl-PC (SLPC). In our model system, free-radical generation was initiated by extended incubation of the liposomes, by induction by 2,2'-azobis(2-amidinopropane)hydrochloride, or by ultraviolet irradiation of H2O2. The rate of consumption of molecular oxygen was studied by monitoring the oxygen concentration in the aqueous phases of the liposomes. The effect of 5 mol% SCLAPC in soy PC was significantly larger than 5 mol% SLPC in soy PC; the response patterns with soy PC and EYPC were similar. Furthermore, 5 mol% SCLAPC in 1-palmitoyl-2-linoleoyl-PC showed similar oxygen consumption to that observed with 5 mol% SCLAPC in EYPC. On the other hand, 5 mol% SCLAPC in synthetic PC membranes containing saturated or monounsaturated fatty acids showed low oxygen depletion rates. The perturbation of membrane structure and the increase of the relative oxygen diffusion-concentration products provided a potential mechanism by which CLA incorporated into membrane lipids could affect oxidative stress.

Electron Spin Resonance Spectroscopy↗

Effects of conjugated linoleic acid isomers on the hepatic microsomal desaturation activities in vitro.

The influence of individual conjugated linoleic acid (CLA) isomers on the delta6 desaturation of linoleic and alpha-linolenic acids and on the delta9 desaturation of stearic acid was investigated in vitro, using rat liver microsomes. The delta6 desaturation of 18:2n-6 was decreased from 23 to 38% when the ratio of 9cis,11trans-18:2 to 18:2n-6 increased from 0.5 to 2. The compound 10trans,12cis-18:2 exhibited a similar effect only at the highest concentration. The delta6 desaturation of alpha-linolenic acid was slightly affected by the presence of CLA isomers. The sole isomer to induce an inhibitory effect on the delta9 desaturation of stearic acid was 10trans,12cis-18:2.

Animals↗