Beneficial effects of a moderate consumption of red wine on cellular cholesterol efflux in young men.

BACKGROUND AND AIM: Protection against coronary artery disease (CAD) by moderate alcohol consumption is thought to be partly mediated through an increase in high density lipoprotein (HDL) levels. The protective effect of HDL can be related to its role in reverse cholesterol transport. Some studies have shown that wine intake is associated with a lower CAD risk compared to other alcoholic beverages. METHODS AND RESULTS: In order to separate the possible beneficial effects of the alcoholic and the non-alcoholic components of red wine, three beverages were compared in a group of 56 healthy young men: red wine (W) (30 g alcohol/day), a solution with the same degree of alcohol (A) and alcohol-free red wine (AFW). Beverages were consumed in random order over a period of 14 days. W significantly increased serum HDL-C, Apo A-I, HDL3-C, LpA-I and LpA-I:A-II particles. With A, only ApoA-I, HDL3-C, LpA-I:A-II were increased, though triglycerides were also increased. AFW had no effect apart from decreasing HDL-C. Plasma CETP was never altered. Serum-promoted cellular cholesterol efflux was measured on 3H labelled Fu5AH cells. Fractional cholesterol efflux was increased only after W intake, by 7%. Efflux variations correlated positively with HDL-C, HDL3-C and HDL-phospholipid variations. CONCLUSIONS: A modest, specific beneficial effect of moderate red wine consumption was demonstrated in comparison to an alcoholic solution. This was due to its effects on lipoproteins and its stimulation of serum ability to induce efflux of cellular cholesterol.

Measurement of apolipoprotein B concentration in plasma lipoproteins by combining selective precipitation and mass spectrometry.

The measurement of apolipoprotein B (apoB) in purified lipoproteins by immunological assays is subject to criticism because of denatured epitopes or immunoreactivity differences between purified lipoproteins and standard. Chemical methods have therefore been developed, such as the selective precipitation of apoB followed by quantification of the precipitate. In this study, we present the measurement of apoB concentration in lipoproteins purified by ultracentrifugation by combining isopropanol precipitation and gas chromatography/mass spectrometry. Very low density lipoprotein (VLDL; d < 1.006 g/mL); VLDL plus intermediate density lipoprotein (VLDL + IDL; d < 1.019 g/mL); and VLDL, IDL, and low density lipoprotein (VLDL + IDL + LDL; d < 1.063 g/mL) were purified by ultracentrifugation. Apolipoprotein B-100 was selectively precipitated by isopropanol. The leucine content of the pellet was then determined by gas chromatography/mass spectrometry, using norleucine as internal standard. Knowledge of the number of leucine molecules in one apoB-100 molecule makes it possible to calculate the plasma concentration of apoB in the various lipoprotein fractions. ApoB in IDL (d 1.006-1.019 g/mL) and LDL (d 1.019-1.063 g/mL) were then determined by subtracting VLDL-apoB from apoB in lipoproteins d < 1.019 and apoB in lipoproteins d < 1.019 g/mL from apoB in lipoproteins d < 1.063 g/mL, respectively. The isopropanol precipitate was verified as pure apoB (>97%) in lipoprotein fractions isolated from normo- and hyperlipidemic plasma and the method appeared reproducible. The combination of isopropanol precipitation and the GC/MS method appears therefore to be a precise and reliable method for kinetic and epidemiological studies.