thiobarbituric-acid and Hyperlipidemias

Research has shown that silicon can play an important role in protecting against degenerative diseases. Restructuring pork by partially disassembling meat permits the incorporation of active components with potential functional effects. However, there has been no research to date on the impact that silicon, as a functional ingredient in restructured pork (RP), has on lipoprotein composition, metabolism, and oxidation.. This study was designed to evaluate the effect of silicon-enriched RP on lipemia, lipoprotein profile, and oxidation markers of aged rats fed high-fat, high-energy, cholesterol-enriched diets.. RP samples similar to commercial sausages (16% protein and 22% fat, wt:wt) were prepared by mixing lean pork and lard alone or with silicon (1.3 g Si/kg fresh matter) under controlled conditions and then freeze-dried. Saturated fat-rich diets were designed by mixing 78.3% purified diet with 21.7% freeze-dried RP. Three groups composed of 8 aged male Wistar rats (1 y old) were fed for 8 wk a control RP (C) diet, a cholesterol-enriched RP (Chol-C) diet [C diet enriched with 1.26% cholesterol plus 0.25% cholic acid, or a cholesterol and silicon-enriched RP (Chol-Si) diet (same as the Chol-C diet but containing silicon)]. Plasma lipid concentrations, lipoprotein profile, the degree of VLDL oxidation, and LDL receptor gene (Ldlr) expression were tested.. Compared with the C diet, the Chol-C diet did not modify food intake or body weight but significantly increased (P < 0.05) plasma cholesterol (32%) and total lipids (19%), VLDL and intermediate density lipoprotein + LDL cholesterol (both >600%), total lipids and proteins (both >300%), and the degree of VLDL oxidation [conjugated dienes >250%; thiobarbituric acid-reactive substance (TBARS), 900%] and reduced Ldlr expression (64%) and liver arylesterase activity (54%). The Chol-Si diet partially normalized changes induced by the Chol-C diet. Compared with the Chol-C group, Chol-Si rats had lower VLDL compound concentrations (P < 0.001; e.g., 75% less VLDL cholesterol) and VLDL oxidation (65% less conjugated dienes and 85% less TBARS) but greater Ldlr expression (200%).. Silicon added to RP strongly counterbalanced the negative effect of high-cholesterol-ingestion, functioning as an active hypocholesterolemic, hypolipemic, and antioxidative dietary ingredient in aged rats.

Topics: Animals; Anticholesteremic Agents; Antioxidants; Biomarkers; Carboxylic Ester Hydrolases; Diet, Atherogenic; Food Additives; Hyperlipidemias; Hypolipidemic Agents; Lipoproteins, LDL; Lipoproteins, VLDL; Liver; Male; Meat Products; Oxidation-Reduction; Rats; Rats, Wistar; Receptors, LDL; Silicon; Swine; Thiobarbiturates

Atherosclerosis and its complications are prevalent worldwide with a high prevalence in western societies. The disease may sometimes be explained by a defect of low density lipoprotein (LDL) specific receptors. However, the prevalence of receptor defect is rather rare and a large body of evidence supports the possibility that an alternative pathway, the so-called "scavenger pathway", constitutes the gate through which cholesterol enters into the parietal wall and gives origin to the "foam cell". Experimental work has clearly demonstrated that LDL may be modified under the action of chemical and biological offenders, all of which make the LDL an "alien". Some papers suggest that the modifications of LDL may occur also "in vivo" in the microenvironment of the vascular vall. In 1988 we were able to record two LDL subfractions in human plasma; the more electronegative minor subfraction shares many of the peculiar traits of LDLs modified "in vitro". The present article stresses all the points which support the hypothesis that the small more electronegative LDL circulating modified LDL, may represent a certain amount of possibly oxidative in origin.

Topics: Animals; Arteriosclerosis; Artifacts; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Humans; Hyperlipidemias; Lipoproteins, LDL; Probucol; Thiobarbiturates