Article

Inhibition of rat lipoprotein oxidation after tetradecylthioacetic acid feeding.

Institute of Clinical Biochemistry, Haukeland University Hospital, University of Bergen, N-5021 Bergen, Norway.
Biochemical Pharmacology (impact factor: 4.7). 04/2002; 63(6):1127-35. pp.1127-35
Source: PubMed

ABSTRACT We have previously shown that tetradecylthioacetic acid (TTA), a sulfur containing saturated fatty acid analogue, inhibits the oxidative modification of human low-density lipoprotein (LDL) in vitro. The oxidative modification of LDL is believed to be a crucial step in the progression of atherosclerosis. In the present study, we investigated the effect of TTA oral administration on the susceptibility of rat lipoprotein to undergo oxidative modification ex vivo. Lipoprotein resistance to copper-induced oxidation was highly improved after TTA administration to rats. Conjugated dienes produced after 150 min of lipoprotein oxidation were dramatically lowered in the TTA treated rats compared to controls. Malondialdehyde and lipid peroxides production by oxidation was highly limited. These effects were independent of any Vitamin E effects. More than 50% relative reduction in polyunsaturated fatty acids of the n-3 family, and more than 30% relative increase in 18:1n-9 fatty acid in the triacylglycerol (TAG)-rich lipoprotein were observed. TAG-rich lipoprotein lipids of TTA fed rats were decreased with more than 50% reduction in TAG. The data reported in this paper indicate a potent in vivo antioxidant capability of TTA that beside its hypolipidemic effect might be of importance in relation to the development of atherosclerosis.

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    Article: Dietary soya protein concentrate enriched with isoflavones reduced fatty liver, increased hepatic fatty acid oxidation and decreased the hepatic mRNA level of VLDL receptor in obese Zucker rats.
    Oddrun A Gudbrandsen, Hege Wergedahl, Sverre Mørk, Bjørn Liaset, Marit Espe, Rolf K Berge
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    ABSTRACT: Casein-based diets containing a low (LDI) or high (HDI) dose of soya protein concentrate enriched with isoflavones were fed to obese Zucker rats for 6 weeks. HDI feeding, but not LDI feeding, reduced the fatty liver and decreased the plasma levels of alanine transaminase and aspartate transaminase. This was accompanied by increased activities of mitochondrial and peroxisomal beta-oxidation, acetyl-CoA carboxylase, fatty acid synthase and glycerol-3-phosphate acyltransferase in liver and increased triacylglycerol level in plasma. The decreased fatty liver and the increased plasma triacylglycerol level appeared not to be caused by an increased secretion of VLDL, as HDI decreased the hepatic mRNA levels of apo B and arylacetamide deacetylase. However, the gene expression of VLDL receptor was markedly decreased in liver, but unchanged in epididymal white adipose tissue and skeletal muscle of rats fed HDI, indicating that the liver may be the key organ for the reduced clearance of triacylglycerol-rich lipoproteins from plasma after HDI feeding. The n-3/n-6, 20:4n-6/18:2n-6 and (20:5n-3+22:6n-3)/18:3n-3 ratios were increased in liver triacylglycerol by HDI. The phospholipids in liver of rats fed HDI contained a low level of 20:4n-6 and a high level of 20:5n-3, favouring the production of anti-inflammatory eicosanoids. When obese Zucker rats were fed soya protein, this also resulted in reduced fatty liver, possibly through reduced clearance of VLDL by the liver. We conclude that the isoflavone-enriched soya concentrate as well as soya protein may be promising dietary supplements for treatment of non-alcoholic fatty liver.
    British Journal Of Nutrition 09/2006; 96(2):249-57. · 3.01 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

30% relative increase
 
50% reduction
 
50% relative reduction
 
Conjugated dienes
 
copper-induced oxidation
 
crucial step
 
fatty acid analogue
 
human low-density lipoprotein
 
hypolipidemic effect
 
lipid peroxides production
 
oxidative modification
 
oxidative modification ex vivo
 
polyunsaturated fatty acids
 
TAG)-rich lipoprotein
 
TAG-rich lipoprotein lipids
 
tetradecylthioacetic acid
 
TTA administration
 
TTA oral administration
 
Vitamin E effects
 
vivo antioxidant capability