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PubMed2000

Synthesis of glycerides containing n-3 fatty acids and conjugated linoleic acid by solvent-free acidolysis of fish oil.

Menhaden oil, a rich source of n-3 fatty acids, was interesterified with conjugated linoleic acid (CLA) in a reaction medium composed solely of substrates and either free or immobilized commercial lipase preparations. Of five lipases tested, an immobilized preparation from Mucor miehei provided the fastest rate of incorporation of CLA into fish oil acylglycerols; however, and as observed with most of the lipases utilized, a significant proportion of the n-3 fatty acid residues were liberated in the process. A soluble lipase from Candida rugosa converted free CLA to acylglycerol residues while leaving the n-3 fatty acid residues virtually untouched. Even though the reaction rate was slower for this enzyme than for the other four lipase preparations, the specificity of the free C. rugosa lipase gives it the greatest potential for commercial use in preparing fish oils enriched in CLA residues but still retaining their original n-3 fatty acid residues.

Biochemistry↗

PubMed2003

The effect of polyunsaturated fatty acids, including conjugated linoleic acid, on calcium absorption and bone metabolism and composition in young growing rats.

The effect of polyunsaturated fatty acids (PUFA), in particular conjugated linoleic acid (CLA), on Ca and bone metabolism is unclear. In a 2x2 factorial design study, forty male 4-week-old rats were fed a control diet containing 70 g added fat (soyabean oil (SBO; n-6 PUFA-rich diet) or menhaden oil-safflower oil (MSO; n-3 PUFA-rich diet))/kg diet with 0 or 10 g CLA/kg for 8 weeks. Ex vivo prostaglandin E2 biosynthesis by bone organ culture was significantly higher (P<0.001) in rats consuming SBO compared with MSO, irrespective of CLA. Addition of the CLA treatment to either diet further lowered (P<0.05) ex vivo prostaglandin E2 production. Neither PUFA type nor CLA altered circulating or femoral mRNA levels of osteocalcin (a marker of bone formation) or insulin-like growth factor-I (a mediator of bone metabolism). While urinary pyridinium crosslinks levels (markers of bone resorption) were unaffected by CLA irrespective of PUFA type, they were significantly higher (P<0.05) in rats consuming SBO compared with MSO irrespective of CLA. Net fractional (%) and absolute (mg) Ca absorption were significantly (P<0.01 and P<0.05 respectively) higher in CLA-supplemented than unsupplemented animals fed on the n-3 PUFA-rich diet, whereas CLA had no effect in animals fed the n-6 PUFA-rich diet. There was no effect of CLA supplementation on bone mineral mass. In conclusion, CLA supplementation over 8 weeks appeared to enhance Ca absorption in young growing rats fed an n-3 PUFA-rich diet, but had no measurable effect on bone metabolism or bone mass over this time frame.

Absorption↗

PubMed2001

Infant plasma trans, n-6, and n-3 fatty acids and conjugated linoleic acids are related to maternal plasma fatty acids, length of gestation, and birth weight and length.

BACKGROUND: Arachidonic acid (AA) and docosahexaenoic acid (DHA) are important for growth and neural development. trans Fatty acids (TFAs) may inhibit desaturation of linoleic acid (LA) and alpha-linolenic acid (ALA) to AA and DHA, respectively. Conjugated linoleic acids (CLAs) also alter lipid metabolism and body fat. OBJECTIVE: We determined the associations of birth outcome with maternal and infant plasma concentrations of TFAs, CLAs, AA, and DHA. DESIGN: In healthy women, we sampled maternal blood at 35 wk gestation (n = 58) and umbilical cord blood at birth (n = 70). RESULTS: Mean (+/- SEM) TFA concentrations (% by wt) in infant plasma were as follows: triacylglycerol, 2.83 +/- 0.19 (range: 0.63-12.79); phospholipid, 0.67 +/- 0.03 (0.11-1.33); and cholesteryl ester, 2.04 +/- 0.01 (0.86-4.24). LA, AA, DHA, TFA, and CLA concentrations in infant phospholipids correlated with the same fatty acid in maternal plasma phospholipids (n = 44; P < 0.05). Infant plasma cholesteryl ester and triacylglycerol TFAs and cholesteryl ester CLAs (r = -0.33, -0.42, and -0.49, respectively) were significantly inversely related to length of gestation. Triacylglycerol and cholesteryl ester AA were positively related to length of gestation (r = 0.41 and 0.37, respectively) and birth weight (r = 0.27 and 0.23, respectively). Inverse correlations occurred between infant plasma TFA and DHA concentrations in triacylglycerols (r = -0.33) and between TFA and AA concentrations in cholesteryl esters (r = -0.23). CONCLUSION: The results suggest possible important effects of TFAs and of AA on fetal growth and length of gestation.

Arachidonic Acid↗

PubMed2002

Bioconversion of vaccenic acid to conjugated linoleic acid in humans.

BACKGROUND: Vaccenic acid (11-trans octadecenoic acid; VA), a major trans fatty acid in the fat of ruminants, is produced in the rumen and converted in tissues to rumenic acid (9-cis, 11-trans octadecenoic acid; RA), an isomer of conjugated linoleic acid, by Delta(9)-desaturase. There are indications that this conversion also occurs in humans. OBJECTIVE: The aim of this controlled intervention was to study the conversion of VA to RA in humans after consumption of diets with increasing amounts of VA. DESIGN: Thirty healthy subjects consumed a baseline diet rich in oleic acid for 2 wk. The subjects were then divided into 3 groups (n = 10 per group) and provided a diet containing 1.5, 3.0, or 4.5 g VA/d for 9 d. All diets contained equal amounts of macronutrients and differed only in their fatty acid compositions. The fats were mixed into conventional foods, and nearly all food was provided during the study. RESULTS: The proportion of VA in serum total fatty acids increased 94%, 307%, and 620% above baseline with the 1.5-, 3.0-, and 4.5-g diets, respectively. This was associated with a linear increase in the proportion of RA. The conversion rate was 19% on average, with significant interindividual differences with all 3 intakes of VA. The urinary excretion of 8-iso-prostaglandin F(2alpha) increased in all groups (P < 0.001). CONCLUSIONS: The results quantify the desaturation of VA to RA in humans. Conversion is likely to contribute significantly to the amount of RA available to the body, and dietary intakes of VA should thus be taken into account when predicting RA status.

Adult↗

PubMed2002

Duodenal and milk trans octadecenoic acid and conjugated linoleic acid (CLA) isomers indicate that postabsorptive synthesis is the predominant source of cis-9-containing CLA in lactating dairy cows.

Duodenal and milk samples obtained from lactating cows in a previous study were analyzed to compare the content and isomer distribution of conjugated linoleic acids (CLA) and trans-18:1 fatty acids (tFA). Four diets containing either low [25 g/100 g dry matter (DM)] or high (60 g/100 g DM) forage were fed with or without 2% added buffer to four multiparous Holstein dairy cows in a 2 x 2 factorial, 4 x 4 Latin square design with 3-wk experimental periods. Duodenal flows of CLA were low (1.02-1.84 g/d), compared with that of tFA (57-120 g/d), regardless of diet. The greatest amounts of CLA and tFA, as well as the greatest proportions of trans-10-18:1 (P < 0.02), and cis-9, trans-11 (P < 0.01) and trans-10, cis-12 CLA (P < 0.01) were in the duodenal flow of cows fed the low forage unbuffered diet. In milk fat, tFA were increased by the low forage unbuffered diet and the trans-10-18:1 (P < 0.02) replaced trans-11-18:1 as the major 18:1 isomer. Milk CLA secretion (7.2-9.1 g/d) was greater (P < 0.001) than that in the duodenal flow with each diet. This was due to the increase in cis-9, trans-11-18:2 and trans-7, cis-9 CLA, resulting most likely from endogenous synthesis via Delta9-desaturation of ruminally derived tFA. For other CLA isomers, duodenal flow was always greater than milk secretion, suggesting that they essentially were produced in the rumen.

Animal Feed↗

PubMed2000

Mammary lipogenic enzyme activity, trans fatty acids and conjugated linoleic acids are altered in lactating dairy cows fed a milk fat-depressing diet.

The objectives of the present study were to examine the effect of a milk fat-depressing (MFD) diet on: 1) the activity of mammary acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), 2) ACC mRNA relative abundance and 3) distributions of conjugated linoleic acids (CLA) and trans-18:1 fatty acids (tFA) in milk fat. Twelve lactating Holstein cows were used in a single reversal design. Two diets were fed: a control diet (60:40% forage/concentrate) and an MFD diet (25:70% forage/concentrate, supplemented with 5% soybean oil). The MFD diet decreased (P: < 0 0.001) milk fat by 43% and ACC and FAS activity by 61 and 44%, respectively. A reduced ACC mRNA relative abundance (P: < 0.001) corresponded with the lower ACC activity. The fatty acids synthesized de novo were decreased (P: < 0. 002), whereas tFA were increased from 1.9 to 15.6% due predominantly to a change in trans-10-18:1 isomer (P: < 0.001). With the MFD diet, the trans-7, cis-9 and trans-10, cis-12 CLA isomers were elevated (P: < 0.001), in contrast to the decrease in trans-11-18:1 (P: < 0. 001) and cis-9, trans-11-18:2. The data were consistent with a dietary effect on mammary de novo FA synthesis mediated through a reduction in ACC and FAS activity and in ACC mRNA abundance. The results were compatible with a role of trans-10, cis-12 CLA in milk fat depression, but alterations noted in tFA and other CLA isomers suggest that they also may be important during diet-induced milk fat depression.

Acetyl-CoA Carboxylase↗

PubMed2003

Partial inhibition of biohydrogenation of linoleic acid can increase the conjugated linoleic acid production of Butyrivibrio fibrisolvens A38.

Butyrivibrio fibrisolvens A38, one of the most active rumen bacteria in conjugated linoleic acid (CLA) production, was characterized in vitro. Previous findings that some inhibitory levels of substrate for biohydrogenation (BH) by B. fibrisolvens A38 resulted in more CLA accumulation led to a prediction that partial inhibition of BH could increase ruminal CLA production. The inhibitory conditions for bacterial growth were less effective on the isomerization step than on the following reduction step. Linoleic acid (LA) was inhibitory not only to cell growth but also to LA hydrogenation, and this effect was greater at high concentrations. The reduction step, converting CLA to hydrogenated products (trans-C18:1 and C18:0), was significantly inhibited, and more CLA accumulated during aerobic incubation when LA was added along with a glycolytic inhibitor, iodoacetate (IAA), to cells that were pre-adapted to LA (1 g/OD at 600 nm/L, P < 0.05). Monensin was more inhibitory than IAA to cell growth but less effective for CLA accumulation. Rumen fluid in the culture medium appeared to activate BH even in an aerobic condition, resulting in a lower CLA level than the control group (P < 0.05). Because the isomerization and reduction steps are coupled reactions in BH of most hydrogenating bacteria including B. fibrisolvens A38 cells, both positive and negative modulations of the reduction steps could be key determinants for CLA accumulation in the rumen.

Animals↗

PubMed2004

An overview of the effect of linoleic and conjugated-linoleic acids on the growth of several human tumor cell lines.

Both n-6 and n-3 polyunsaturated fatty acids are dietary fats important for cell function, being involved in several physiologic and pathologic processes, such as tumorigenesis. Linoleic acid and conjugated linoleic acid, its geometrical and positional stereoisomer, were tested on several human tumor cell lines originating from different tissues and with different degrees of malignancy. This was to provide the widest possible view of the impact of dietary lipids on tumor development. While linoleic acid exerted different effects, ranging from inhibitory to neutral, even promoting growth, conjugated linoleic acid inhibited growth in all lines tested and was particularly effective against the more malignant cells, with the exception of mammary tumor cells, in which behavior was the opposite, the more malignant cell line being less affected. The inhibitory effect of conjugated linoleic acid on growth may be accompanied by different contributions from apoptosis and necrosis. The effects of conjugated linoleic acid on growth or death involved positive or negative variations in PPARs. The important observation is that a big increase of PPARalpha protein occurred in cells undergoing strong induction of apoptosis, whereas PPARbeta/delta protein decreased. Although PPARalpha and PPARbeta/delta seem to be correlated to execution of the apoptotic program, the modulation of PPARgamma appears to depend on the type of tumor cell, increasing as protein content, when inhibition of cell proliferation occurred. In conclusion, CLA may be regarded as a component of the diet that exerts antineoplastic activity and its effect may be antiproliferative or pro-apoptotic.

Antineoplastic Agents↗

PubMed2006

Polyunsaturated fatty acids and conjugated linoleic acid isomers in breast milk are associated with plasma non-esterified and erythrocyte membrane fatty acid composition in lactating women.

Maternal adipose tissue is a major contributor to breast milk long-chain fatty acids, probably through the pool of plasma NEFA. The fatty acid composition of the erythrocyte membrane (EM) is a biochemical index of the intake of fatty acids not synthesized endogenously and of PUFA and long-chain PUFA fatty acid status. The present study investigated the associations between breast milk fatty acid composition and the composition of plasma NEFA and of EM fatty acids with special reference to PUFA, long-chain PUFA and conjugated linoleic acid (CLA). The detailed fatty acid composition of mature breast milk was also reported. Thirty-three healthy, lactating Brazilian women donated milk samples; of these, twenty-four also donated blood samples in an observational cross-sectional study. Breast milk fatty acid composition presented several associations with NEFA and EM composition, which explained most (> or =50 %) of the variability of selected milk PUFA, long-chain PUFA and CLA. Milk CLA was associated with fatty acids that are markers of dairy fat intake in the diet, NEFA and EM. In general, breast milk n-3 fatty acids and CLA, but not n-6 fatty acids, were associated with EM composition, whereas both the n-6 and n-3 fatty acids and CLA in milk were associated with NEFA composition, possibly owing to its role as a direct source of fatty acids for breast milk. These findings emphasize the contribution of the NEFA pool derived from the adipose tissue to the long-chain fatty acid composition of breast milk.

Adult↗

PubMed2006

Effects of conjugated linoleic acid supplementation in layer diet on fatty acid compositions of egg yolk and layer performances.

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of linoleic acid with conjugated double bonds. Conjugated linoleic acids have been reported to have a wide range of health-beneficial effects, including anticarcinogenic, antiatherogenic, antidiabetic, and immune stimulatory effects. The objective of this study was to investigate the incorporation of CLA into eggs. Three hundred 27-wk-old layers were allocated to 5 dietary treatments (0, 1, 2, 3, and 4% CLA) with 5 replicates. The results of the study showed that average daily feed intakes were similar in all treatment groups, although hens fed with 4% CLA tended to consume less feed than other hens. Body weight gain and mortality rate were not significantly different (P > 0.05). Hens fed 4% dietary CLA had reduced egg, yolk, and albumen weights (P < 0.05). Yolk color significantly decreased as dietary CLA increased (P < 0.01). Shell thickness and Haugh units were not influenced by the dietary CLA. Concentrations of CLA and saturated fatty acids in egg yolk lipids increased as dietary CLA increased (P < 0.01), whereas concentrations of monounsaturated fatty acids and polyunsaturated fatty acids decreased as dietary CLA increased (P < 0.01). It can be concluded from the present experiments that increasing the amount of CLA fed to hens will increase the amount of CLA in egg yolk and that this increase is accompanied by a reduction in the amount of yolk polyunsaturated fatty acids but an increase in yolk saturated fatty acids. Egg size, yolk weight, and Roche-fan determined yolk color significantly decreased at the highest level of CLA supplementation.

Animal Feed↗

PubMed2002

Effects of dietary fat source and breed on the carcass composition, n-3 polyunsaturated fatty acid and conjugated linoleic acid content of sheep meat and adipose tissue.

Seventy-two 8-week-old ram lambs from three breeds, Suffolk, Soay and Friesland, were offered one of four diets based on dried grass and formulated to have a similar fatty acid content (60 g/kg DM) and containing: Megalac (high in 16 : 0, control; Volac Ltd, Royston, Herts., UK), whole linseed (18 : 3n-3), fish oil (20 : 5n-3 and 22 : 6n-3) or whole linseed plus fish oil. The lambs were slaughtered at approximately half of their mature live weight (43, 21 and 43 kg for Suffolk, Soay and Friesland lambs, respectively). Fish oil reduced DM intake and lamb live-weight gain (P<0.001), while DM intake, live-weight gain and subcutaneous fat content were highest in Suffolk and lowest in Soay lambs. Linseed feeding doubled the proportion (x100) of 18 : 3n-3 in the longissimus dorsi from 1.4 to 3.1 and in the subcutaneous adipose tissue from 1.2 to 2.6 (P<0.001). Suffolk and particularly Soay lambs contained higher proportions of 18 : 3n-3 than Friesland lambs in the longissimus dorsi, while in the adipose tissue, Suffolk lambs had the highest level. Feeding fish oil increased the muscle proportion (x100) of 20 : 5n-3 from 0.7 to 2.3 and 22 : 6n-3 from 0.3 to 0.8 (P<0.001). By contrast, the proportions of the longer-chain n-3 polyunsaturated fatty acids were similar across all three breeds. All three lipid supplements containing n-3 polyunsaturated fatty acids increased the content of muscle trans-18 : 1 relative to the control values, but conjugated linoleic acid (cis-9,trans-11-18 : 2) only increased in the muscle of lambs fed linseed. Feeding linseed or fish oil lowered the n-6 : n-3 ratio in sheep meat, but neither diet nor breed had much effect on the polyunsaturated fatty acid: saturated fatty acid ratio.

Adipose Tissue↗

PubMed2003

Association of liver steatosis with lipid oversecretion and hypotriglyceridaemia in C57BL/6j mice fed trans-10,cis-12-linoleic acid.

Conjugated linoleic acids (CLA) have recently been recognized to reduce body fat and plasma lipids in some animals. This study demonstrated that the steatosis accompanying the fat loss induced by trans-10,cis-12-C(18:2) (CLA2) and not cis-9,trans-11-C(18:2) (CLA1) isomer in C57BL/6j mice was not due to an alteration of the liver lipoprotein production that was even increased. The 3-fold decrease in plasma triacylglycerol contents and the induction of mRNA expression of low-density lipoprotein receptors concomitantly observed in CLA2-fed mice suggested an increase in the lipoprotein clearance at the level of the liver itself. CLA1 feeding produced similar but attenuated effects on triglyceridaemia only.

Animals↗

PubMed2006

NF-kappaB independent inhibition of lipopolysaccharide-induced cyclooxygenase by a conjugated linoleic acid cognate, conjugated nonadecadienoic acid.

10t, 12c-CLA was shown to inhibit COX-2 expression through the NF-kappaB pathway. In the current study, conjugated nonadecadienoic acid (CNA) was shown to decrease inducible COX-2 protein and mRNA and PGE(2) release to the similar extent as 10t, 12c-CLA in Raw264.7 macrophage. However, unlike 10t, 12c-CLA, inhibition of COX-2 mRNA/protein by CNA was independent of the NF-kappaB pathway. The data indicate the regulation of COX-2 by select conjugated fatty acids and hence their anti-inflammatory actions could operate through different signal transduction pathways.

Animals↗

PubMed2004

Enrichment of conjugated linoleic acid in oats (Avena sativa L.) by microbial isomerization.

A method for microbial isomerization of oat linoleic acid to conjugated linoleic acid (CLA) was developed. The method includes hydrolysis of oat lipids in aqueous flour slurries by the endogenous oat lipase. Then, the flour slurry containing free linoleic acid is utilized as a substrate for the isomerization reaction carried out by resting cells of Propionibacterium freudenreichii ssp. shermanii. The isomerization reaction progressed most effectively when, after the lipid hydrolysis period, the pH of the slightly acidic oat slurry was elevated to 8.0-8.5 and maintained at this range. With slurries containing 5% (w/v) oat flour, the amounts of CLA formed per dry matter were up to 10.1 mg/g corresponding to 102 mg/g lipids or 0.44 mg/mL slurry. Increments in the flour content up to 15% increased the volumetric production of CLA to 0.85 mg/mL. The proportion of the cis-9,trans-11 isomer was 80% of the total CLA formed. CLA could be concentrated into the solid material of the oat slurry by acidification.

Avena↗

PubMed2003

Interactions of conjugated linoleic acid and lipoic acid on insulin action in the obese Zucker rat.

The fatty acid conjugated linoleic acid (CLA) and the antioxidant R-(+)-alpha-lipoic acid (R-ALA) individually enhance glucose tolerance and insulin action on skeletal muscle glucose transport in the insulin-resistant obese Zucker rat. To date, no study has assessed the potential interactions between these 2 interventions in treating insulin resistance. The present study was designed to determine whether chronic treatment with CLA and R-ALA in combination would enhance skeletal muscle glucose transport to a greater extent than either intervention individually. CLA, R-ALA, or a combination treatment of R-ALA and CLA were administered to female obese Zucker rats for 20 days at low or high doses. Whereas low-dose R-ALA (10 mg/kg body weight) alone did not alter muscle glucose transport, low-dose CLA (0.3 g/kg) induced a significant increase (38%, P <.05) in insulin-mediated glucose transport in epitrochlearis, but not in soleus. Low-dose combination therapy brought about the greatest enhancement of insulin-mediated glucose transport in epitrochlearis (77%) and soleus (54%), with the latter effect being associated with a 50% reduction in protein carbonyls (an index of tissue oxidative stress) and a 33% diminution in muscle triglycerides. High-dose treatments with CLA (1.5 g/kg), R-ALA (50 mg/kg), and the combination of CLA and R-ALA elicited increases in insulin-mediated glucose transport in epitrochlearis (57%, 58%, and 77%) and soleus (32%, 35%, and 54%). However, whereas the individual high-dose treatments with CLA and R-ALA reduced protein carbonyls (63% and 49%) and triglycerides (29% and 28%) in soleus, no further reductions were observed with the high-dose combination treatment groups. These findings support a significant interaction between low doses of CLA and R-ALA for enhancement of insulin action on skeletal muscle glucose transport, possibly via reductions in muscle oxidative stress and in lipid storage.

Animals↗

PubMed2003

Isomer-specific actions of conjugated linoleic acid on muscle glucose transport in the obese Zucker rat.

The fatty acid-conjugated linoleic acid (CLA) enhances glucose tolerance and insulin action on skeletal muscle glucose transport in rodent models of insulin resistance. However, no study has directly compared the metabolic effects of the two primary CLA isomers, cis-9,trans-11-CLA (c9,t11-CLA) and trans-10,cis-12-CLA (t10,c12-CLA). Therefore, we assessed the effects of a 50:50 mixture of these two CLA isomers (M-CLA) and of preparations enriched in either c9,t11-CLA (76% enriched) or t10,c12-CLA (90% enriched) on glucose tolerance and insulin-stimulated glucose transport in skeletal muscle of the insulin-resistant obese Zucker (fa/fa) rat. Animals were treated daily by gavage with either vehicle (corn oil), M-CLA, c9,t11-CLA, or t10,c12-CLA (all CLA treatments at 1.5 g total CLA/kg body wt) for 21 consecutive days. During an oral glucose tolerance test, glucose responses were reduced (P < 0.05) by 10 and 16%, respectively, in the M-CLA and t10,c12-CLA animals, respectively, whereas insulin responses were diminished by 21 and 19% in these same groups. There were no significant alterations in these responses in the c9,t11-CLA group. Insulin-mediated glucose transport activity was enhanced by M-CLA treatment in both type I soleus (32%) and type IIb epitrochlearis (58%) muscles and by 36 and 48%, respectively, with t10,c12-CLA. In the soleus, these increases were associated with decreases in protein carbonyls (index of oxidative stress, r = -0.616, P = 0.0038) and intramuscular triglycerides (r = -0.631, P = 0.0028). Treatment with c9,t11-CLA was without effect on these variables. These results suggest that the ability of CLA treatment to improve glucose tolerance and insulin-stimulated glucose transport activity in insulin-resistant skeletal muscle of the obese Zucker rat are associated with a reduction in oxidative stress and muscle lipid levels and can be specifically ascribed to the actions of the t10,c12 isomer. In the obese Zucker rat, the c9,t11 isomer of CLA is metabolically neutral.

Abdomen↗

PubMed2006

Production of trans-10, cis-12 conjugated linoleic acid in rice.

Conjugated linoleic acid (CLA) has anti-carcinogenic and anti-atherosclerosis activity, and modulatory effects on the immune system and lipid metabolism. To produce a transgenic rice plant that can accumulate CLA, a linoleate isomerase gene that can convert linoleic acid to trans-10, cis-12 CLA was introduced and expressed under the control of seed-specific promoters from the oleosin and globulin genes. The fatty acid composition of the transgenic rice grain was analyzed by gas chromatography. Although there was no clear difference in the fatty acid composition between seeds from transformed versus untransformed plants, a peak of trans-10, cis-12 CLA methyl ester, which was not present in seeds from untransformed plants, was found in transformed plants. The trans-10, cis-12 CLA comprised an average of 1.3% (w/w) of the total fatty acids in seeds carrying the oleosin promoter in comparison to 0.01% (w/w) in seeds carrying the globulin promoter. In addition, approximately 70 and 28% of the total amount of the CLA isomer were present in the triacylglycerol and free fatty acid fractions, respectively. These results demonstrate the ability to produce fatty acid components of vegetable oils with novel physiological activities in crops.

Chromatography, Gas↗

PubMed2004

Total antioxidant capacity of arginine-conjugated linoleic acid (CLA) complex.

Conjugated linoleic acids (CLA) have shown diverse biological activities, including anti-carcinogenic, anti-atherosclerotic, anti-adipogenic, and anti-diabetogenic effects. Recent reports also showed that CLA has free radical scavenging capacity, which may give health benefits to human beings. However, the application of CLA as a bioactive ingredient has been limited due to its insolubility in water. To overcome this problem, we investigated antioxidant activities of arginine (Arg)-CLA, a water-soluble CLA salt, using both 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. CLA, Arg, and Arg-CLA all exerted radical scavenging activities in a dose-dependent manner in both assays. Arg-CLA at 20 mM scavenged 89 and 55% of ABTS and DPPH radicals in 3 h, respectively, whereas CLA alone quenched only 48 and 26% of them under the same conditions. The antioxidant activity of the Arg-CLA complex was found to be synergistic in ABTS assay and comparable to that of vitamin E in DPPH assay.

Antioxidants↗