Individual Trans Octadecenoic Acids and Partially Hydrogenated Vegetable Oil Differentially Affect Hepatic Lipid and Lipoprotein Metabolism in Golden Syrian Hamsters

Abstract

Trans fatty acids (TFA) from industrial sources [i.e. partially hydrogenated vegetable oil (PHVO)] have been associated with several chronic human diseases, especially coronary heart disease (CHD). The possible contribution of individual TFA to overall CHD risk remains largely unknown. The objective of the present study was to investigate the effects of 2 major trans 18:1 isomers, trans-9 18:1 [elaidic acid (EA)] and trans-11 18:1 [vaccenic acid (VA)] on plasma lipid biomarkers of CHD risk. Thirty-two male Golden Syrian hamsters were randomly assigned to 1 of 4 dietary treatments: 1) control "Western" diet; 2) PHVO supplement; 3) EA supplement; and 4) VA supplement. Fat supplements were incorporated into the respective treatment diets at 2.5 g/100 g of diet. Compared with the control diet, the PHVO diet increased the plasma ratios of total:HDL-cholesterol and nonHDL:HDL-cholesterol by 17 and 23%, respectively. In contrast, these values decreased by 27 and 46% after the EA treatment and 8 and 14% after the VA treatment, respectively, indicating an improvement (reduction) in CHD risk. With regard to liver lipids, the EA diet reduced the content of (n-3) and (n-6) PUFA relative to the other treatments, suggesting an inhibition of enzymes common to the 2 biosynthesis pathways. Overall, results demonstrate that the hypercholesterolemic effects of PHVO are not dependent on the presence of EA or VA and that other bioactive components in PHVO must be responsible for its associated adverse health effects.

Ozone-induced dissociation on a modified tandem linear ion-trap: Observations of different reactivity for isomeric lipids

“…Such unequivocal assignments are made despite the fact that numerous studies employing either selective enzymes or chromatographic methods have shown that both glycerophospholipids and triacylglycerols often appear in biology as mixtures of sn-positional isomers [5][6][7][8][9]. Despite the recent interest in the involvement of trans-fatty acids in increasing the risk of several chronic human diseases, particularly coronary heart disease [10,11], there has been relatively little attention paid to the possibility of stereoisomerism in complex lipids. This arises because differentiating stereoisomers represents a fundamental challenge for mass spectrometry.…”

Animal models for the atherosclerosis research: a review

“…Even with the limited data to date, the inbred F1B hamster has been more consistently reported to develop an atherogenic lipoprotein profile than any of the other three outbred strains (i.e., CR, Sasco (Kahlon et al, 1996;Kahlon et al, 1997), and Harlan hamsters (Lock et al, 2005;Tyburczy et al, 2009); for a review, see (Dillard et al, 2010)). However, due to the inconsistent and unrepeatable results of aortic lesions in response to dietary fat type in recent studies, hamsters are no longer a suitable model for studying dietinduced atherosclerosis (Dillard et al, 2010) (Table 1).…”

Animal Models as Tools for Translational Research: Focus on Atherosclerosis, Metabolic Syndrome and Type-II Diabetes Mellitus

“…F1B hamster is an exciting animal model for hyperlipidemic-related applications. The F1B strain is very responsive to SF and cholesterol by increasing the non-HDL fraction to a greater extent than the HDL fraction [75]. Dietary fatty acid chain length, degree of saturation and cis-trans conformation have been shown to alter several metabolic pathways involving cholesterol throughout the body, the combined effect of which is reflected in plasma lipid and lipoprotein profiles (see review [76]).…”

“…The authors have shown that fructose feeding for 3 weeks increases secretion of apoB48-containing lipoproteins in the fasting state and during steady state fat feeding. Wang and coworkers [75] investigated the composition of plasma lipoproteins in hamsters fed high-carbohydrate diets of varying complexity (60% carbohydrate as chow, cornstarch, or fructose) for 2 weeks. They showed that hamsters fed the high-fructose diet showed significantly increased VLDL-triglyceride (92.3%), free cholesterol (68.6%), and phospholipid (95%), whereas apolipoprotein B levels remained unchanged.…”