Metabolites of conjugated isomers of linoleic acid (CLA) in the rat

Sébédio, J. L.; Juanéda, Pierre; Dobson, Gary; Ramilison, I; Martin, Jean-Charles; Chardigny, Jean Michel; Christie, William W.

doi:10.1016/s0005-2760(97)00015-5

Cited by 167 publications

(119 citation statements)

References 23 publications

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“…This may relate to the isomer being metabolized, via desaturation and elongation pathways (Sebedio et al, 1997), or being more easily oxidized due to its structure (Martin et al, 2000). However, irrespective of the reasons for the lack of incorporation into plasma lipids, a low exposure of bone cells to circulating trans-10,cis-12 isomer of CLA (potentially the more bone-active isomer of CLA) might be one explanation of the lack of effect of CLA supplementation on bone metabolism in the present study.…”

Section: Conjugated Linoleic Acid and Bone Metabolism L Doyle Et Almentioning

confidence: 99%

Effect of dietary supplementation with conjugated linoleic acid on markers of calcium and bone metabolism in healthy adult men

et al. 2005

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Introduction: Conjugated linoleic acid (CLA) has been shown to positively influence calcium and bone metabolism in experimental animals and cells in culture, but there are limited human data available. Objective: To investigate the effect of CLA supplementation on biomarkers of calcium and bone metabolism in healthy adult males. Design: The study consisted of a double-blind, placebo-controlled trial in which 60 healthy adult males (aged 39-64 y) were randomly assigned to receive daily either 3.0 g CLA isomer blend (50:50% cis-9,trans-11:trans-10,cis-12 isomers) or a palm/bean oil blend (placebo) for 8 weeks. Urine and blood samples were collected at weeks 0 and 8 and were analysed for biomarkers of calcium and bone metabolism. Results: Supplementation with CLA or placebo for 8 weeks had no significant effects on markers of bone formation (serum osteocalcin and bone-specific alkaline phosphatase) or bone resorption (serum C-telopeptide-related fraction of type 1 collagen degradation products, urinary N-telopeptide-related fraction of type 1 collagen degradation products, urinary pyridinoline and deoxypyridinoline), or on serum or urinary calcium levels. Baseline levels of these biochemical parameters were similar in both groups of subjects. While the placebo had no effect, CLA supplementation resulted in a three-fold increase (Po0.00001) in cis-9,trans-11 CLA isomer in total plasma lipids.Conclusion: Under the conditions tested in this double-blind, placebo-controlled trial in adult men, a CLA supplement of mixed isomers did not affect markers of calcium or bone metabolism. Further investigation of the effects of CLA on calcium and bone metabolism in other gender-and age-groups is warranted. Sponsorship: Irish Government.

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Section: Conjugated Linoleic Acid and Bone Metabolism L Doyle Et Almentioning

confidence: 99%

Effect of dietary supplementation with conjugated linoleic acid on markers of calcium and bone metabolism in healthy adult men

et al. 2005

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“…The presence of these derivatives has been mentioned in the liver of different species such as the rat [16][17][18]21], lamb [19] and mouse [20]. Moreover, it has been recently demonstrated in the rat that the liver is able to convert rumenic acid into a conjugated derivative identified on the basis of its retention time as the cis-6, cis-9, trans-11 C18:3 [21].…”

Section: Discussionmentioning

confidence: 99%

“…FA methyl esters (FAME) were prepared from total lipids at room temperature by using sodium methylate (1 M) followed by boron trifluoride in methanol (14% v/v) as previously described by Sébédio et al [17]. FAME containing [1-14 C] FAME were then analysed by gas-liquid chromatography using a Hewlett-Packard 5890 series II gas chromatograph (Palo Alto, CA) equipped with a splitless injector and fused Stabilwax wide-bore silica column (60 m × 0.53 mm i.d., film thickness: 0.50 µM, Restek, Evry, France).…”

Section: Determination Of Fa Bioconversionmentioning

confidence: 99%

“…In such situations, large amounts of FA, including CLA which are stored in adipose tissues, are released into the blood and taken up by the liver. The intensity of the different CLA metabolic pathways in the liver is still poorly documented except for the fact that in the liver of different species such as the rat [16][17][18], lamb [19] and mouse [20] given CLA-supplemented diets, CLA is converted into conjugated C18:3 by ∆6 desaturase activity [2,17]. Although these studies reported the presence of CLA derivatives in the liver of animals, only Gruffat et al [21] recently demonstrated, by using rat liver slices incubated with cis-9, trans-11 and trans-10, cis-12 CLA isomers, that CLA conversion into conjugated C18:3 actually occurs in this organ.…”

Section: Introductionmentioning

confidence: 99%

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In vitro metabolism of rumenic acid in bovine liver slices

et al. 2005

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-Ruminant products are the major source of CLA for humans. However, during periods of fat mobilization, the liver might play an important role in CLA metabolism which would limit the availability of the latter for muscles and milk. In this context, rumenic acid (cis-9, trans-11 CLA) metabolism in the bovine liver (n = 5) was compared to that of oleic acid (n = 3) by using the in vitro liver slice method. Liver slices were incubated for 17 h in a medium containing 0.75 mM of FA mixture and 55 µM of either [1-14 C] rumenic acid or [1-14 C] oleic acid at 37 °C under an atmosphere of 95% O 2 -5% CO 2 . Rumenic acid uptake by liver slices was twice (P = 0.009) that of oleic acid. Hepatic oxidation of both FA (> 50% of incorporated FA) led essentially to the production of acidsoluble products and to a lower extent to CO 2 production. Rumenic acid was partly converted (> 12% of incorporated rumenic acid) into conjugated C18:3. CLA and its conjugated derivatives were mainly esterified into polar lipids (71.7%), whereas oleic acid was preferentially esterified into neutral lipids (59.8%). Rumenic acid secretion as part of VLDL particles was very low and was onefourth lower than that of oleic acid. In conclusion, rumenic acid was highly metabolized by bovine hepatocytes, especially by the oxidation pathway and by its conversion into conjugated C18:3 for which the biological properties need to be elucidated. rumenic acid / oleic acid / metabolism / liver / bovine Abbreviations: ASP, acid-soluble products; BSA, bovine serum albumin; CLA, conjugated linoleic acid; FA, fatty acids; NL, neutral lipids; PL, polar lipids; VLDL, very-low density lipoproteins.

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“…By the same deduction, the low content of c/t CLA isomers in the liver PL could be due to rapid metabolism, oxidation and poor geometrical configuration. In this regard, Sebedio et al (1997) analysed the conjugated 20 : 3 and 20 : 4 isomers in rats fed a diet containing 180 mg CLA/d and suggested that some c/t CLA isomers were preferentially metabolised to form longer-chain products via desaturation and elongation pathways, thus leading tissue to accumulate more t/t but fewer c/t isomers. The distribution of CLA and its metabolites into rat liver lipid classes has also been reported by Banni et al (2001).…”

Section: Discussionmentioning

confidence: 99%

Preferential incorporation of <I>trans</I>, <I>trans</I>-conjugated linoleic acid isomers into the liver of suckling rats

Yang

Yeung

Huang

et al. 2002

British Journal of Nutrition

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The present study was designed to compare the conjugated linoleic acid (CLA) isomeric distribution pattern in the liver of suckling rats in relation to those in the milk and maternal diet. Silver-ion HPLC was used to separate individual CLA isomers. It was found that the isomeric distribution pattern in the milk was very similar to that in the maternal dietary fat. However, the CLA isomeric distribution patterns in the liver phospholipids (PL) and triacylglycerols were different from those in the diet and milk. In the liver PL, total cis/trans isomers accounted for 63·6-63·9 % of total CLA, which was in contrast to the values of 88·1-89·1 % in the milk and diet. In the liver PL, total trans/trans isomers were 20·6-20·8 % of the total CLA isomers whereas they were only 2·6-3·7 % in the milk and diet. It is concluded that trans/trans-CLA were preferentially incorporated into the liver whereas for the incorporation of cis/trans-CLA there was partial discrimination.

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Metabolites of conjugated isomers of linoleic acid (CLA) in the rat

Cited by 167 publications

References 23 publications

Effect of dietary supplementation with conjugated linoleic acid on markers of calcium and bone metabolism in healthy adult men

Effect of dietary supplementation with conjugated linoleic acid on markers of calcium and bone metabolism in healthy adult men

In vitro metabolism of rumenic acid in bovine liver slices

Preferential incorporation of <I>trans</I>, <I>trans</I>-conjugated linoleic acid isomers into the liver of suckling rats

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