Conjugated Linoleic Acid Isomers and Cancer ,

Kelley, Nirvair S; Hubbard, Neil E.; Erickson, Kent L.

doi:10.1093/jn/137.12.2599

Cited by 304 publications

(213 citation statements)

References 51 publications

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“…Adapted from Griinari and Bauman (1999). Ip et al, 2002;Kelley et al, 2007) and reduced adiposity (reviewed by Pariza, 2004), although only a mixed preparation including both cis-9, trans-11 and trans-10, cis 12 CLA was available in the original experiments. Similarly, this mixed CLA preparation also reduced milk fat yield in dairy cows (Loor and Herbein, 1998;Chouinard et al, 1999a and1999b).…”

Section: Biohydrogenation Intermediatesmentioning

confidence: 99%

Recent advances in the regulation of milk fat synthesis

Harvatine

Boisclair

Bauman

2009

Animal

268

272

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In addition to its economic value, milk fat is responsible for many of milk's characteristics and can be markedly affected by diet. Diet-induced milk fat depression (MFD) was first described over a century ago and remains a common problem observed under both intensive and extensive management. The biohydrogenation theory established that MFD is caused by an inhibition of mammary synthesis of milk fat by specific fatty acids (FA) produced as intermediates in ruminal biohydrogenation. During MFD, lipogenic capacity and transcription of key lipid synthesis genes in the mammary gland are down-regulated in a coordinated manner. Our investigations have established that expressions of sterol response element-binding protein 1 (SREBP1) and SREBP-activation proteins are down-regulated during MFD. Importantly, key lipogenic enzymes are transcriptionally regulated via SREBP1. Collectively, these results provide strong evidence for SREBP1 as a central signaling pathway in the regulation of mammary FA synthesis. Spot 14 is also down-regulated during MFD, consistent with a lipogenic role for this novel nuclear protein. In addition, SREBP1c and Spot 14 knock-out mice exhibit reduced milk fat similar to the magnitude and pattern of MFD in the cow. Application of molecular biology approaches has provided the latest chapter in the regulation of milk fat synthesis and is reviewed along with a brief background in nutritional regulation of milk fat synthesis in ruminants.

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Section: Biohydrogenation Intermediatesmentioning

confidence: 99%

Recent advances in the regulation of milk fat synthesis

Harvatine

Boisclair

Bauman

2009

Animal

268

272

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“…Interfering with components of the cell cycle might be of benefit in tumour management (CLA inhibits level of the cyklins D and A, and up-regulates p53 expression) (Kelley et al 2007, Stachowska 2008. CLA antitumoric action is also attributed to alteration of lipid peroxidation, eicosanoid metabolism and gene expression (Kelley et al 2007).…”

Section: Cla and Cancermentioning

confidence: 99%

Biological effects of conjugated linoleic acids supplementation

Oleszczuk¹,

Oleszczuk²,

Siwicki³

et al. 2012

Polish Journal of Veterinary Sciences

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Conjugated linoleic acids (CLA) are a group of polyunsaturated fatty acids (PUFA) with a single pair of conjugated double bonds. The major natural CLA isomer is 18:2 cis-9, trans-11 (c9, t11) linoleic acid, or rumenic acid (RA). Chemically synthesized CLA is also available, mostly as a mixture of RA and 18:2 trans-10, cis-12 (t10, c12) isomers in equal amounts (50:50). Consumption of ruminant meat (beef and lamb) and dairy products (milk and cheese) is the main source of dietary exposure to CLA. Despite numerous studies on animal and human models (tumorigenesis, obesity, immune response) it has not been established whether additional supplementation of CLA is of benefit. Moreover, some studies, conducted both in animals and in humans, reveal that CLA isomers may induce insulin resistance. Presently, balanced diet rich in CLA from natural sources is recommended. The purpose of this review was to sum up the results available in the literature.

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“…Today a number of beneficial physiological properties are attributed to CLA such as anti-cancer, anti-atherosclerosis, anti-inflammatory, and anti-obesity effects (reviewed in Scimeca 1999;Gnädig et al 2001;Pariza et al 2001;Evans ME et al 2002;Belury 2002;Terpstra 2004;Wahle et al 2004;Zulet et al 2005; Kelley et al 2007;Li et al 2008). These beneficial effects seem to be structure-specific.…”

Section: Introductionmentioning

confidence: 99%

Autoxidation of Conjugated Linoleic Acid Methyl Ester in the Presence of α‐Tocopherol: The Hydroperoxide Pathway

Pajunen

Johansson

Hase

et al. 2008

Lipids

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The autoxidation of conjugated linoleic acid (CLA) is poorly understood in spite of increasing interest in the beneficial biological properties of CLA and growing consumption of CLA-rich foods. In this thesis, the autoxidation reactions of the two major CLA isomers, 9-cis,11-transoctadecadienoic acid and 10-trans,12-cis-octadecadienoic acid, are investigated. The results contribute to an understanding of the early stages of the autoxidation of CLA methyl ester, and provide for the first time a means of producing and separating intact CLA methyl ester hydroperoxides as well as basic knowledge on lipid hydroperoxides and their hydroxy derivatives.Conjugated diene allylic monohydroperoxides were discovered as primary autoxidation products formed during autoxidation of CLA methyl esters in the presence and absence oftocopherol. This established that one of the autoxidation pathways of CLA methyl ester is the hydroperoxide pathway.Hydroperoxides were produced from the two major CLA methyl esters by taking advantage of the effect of -tocopherol to promote hydroperoxide formation. The hydroperoxides were analysed and separated first as methyl hydroxyoctadecadienoates and then as intact hydroperoxides by HPLC. The isolated products were characterized by UV, GC-MS, and NMR techniques. In the presence of a high amount of -tocopherol, the autoxidation of CLA methyl ester yields six kinetically-controlled conjugated diene monohydroperoxides and is diastereoselective in favour of one particular geometric isomer as a pair of enantiomers. The primary autoxidation products produced from the two major CLA isomers include new positional isomers of conjugated diene monohydroperoxides, the 8-, 10-, 12-, and 14-hydroperoxyoctadecadienoates. Furthermore, two of these new positional isomers have an unusual structure for a cis,trans lipid hydroperoxide where the allylic methine carbon is adjacent to the cis instead of the usual trans double bond.The 1 H and 13 C NMR spectra of nine isomeric methyl hydroxyoctadecadienoates and of ten isomeric methyl hydroperoxyoctadecadienoates including the unusual cis,trans hydroperoxides, i.e. Me 8-OOH-9c,11t and Me 14-OOH-10t,12c, were fully assigned with the aid of 2D NMR spectroscopy. The assigned NMR data enabled determination of the effects of the hydroxyl and hydroperoxyl groups on the carbon chemical shifts of CLA isomers, identification of diagnostic signals, and determination of chemical shift differences of the olefinic resonances that may help with the assignment of structure to as yet unknown lipid hydroperoxides either as hydroxy derivatives or as intact hydroperoxides.A mechanism for the hydroperoxide pathway of CLA autoxidation in the presence of a high amount of -tocopherol was proposed based on the characterized primary products, their relative distribution, and theoretical calculations. This is an important step forward in CLA research, where exact mechanisms for the autoxidation of CLA have not been presented before. Knowledge of these hydroperoxide formation steps is of cr...

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Conjugated Linoleic Acid Isomers and Cancer ,

Cited by 304 publications

References 51 publications

Recent advances in the regulation of milk fat synthesis

Recent advances in the regulation of milk fat synthesis

Biological effects of conjugated linoleic acids supplementation

Autoxidation of Conjugated Linoleic Acid Methyl Ester in the Presence of α‐Tocopherol: The Hydroperoxide Pathway

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