Biomedical subjects

Suleen S Ho

Publications and source records attributed to Suleen S Ho.

3 recordsLinked to original sources

PubMed2005

Red wine polyphenolics suppress the secretion of ApoB48 from human intestinal CaCo-2 cells.

Epidemiological studies suggest that the consumption of red wine lowers the risk of cardiovascular disease. Although the cardioprotective effect of red wine has been attributed to its polyphenolic content, presently, very little is known about the mechanisms by which these compounds benefit the cardiovascular system. Therefore, the aim of this study was to elucidate whether red wine polyphenolics attenuate the synthesis and secretion of proatherogenic chylomicrons from intestinal cells. Apolipoprotein B48 levels (marker of intestinal chylomicrons), quantitated by western blotting, were significantly reduced by 30% in cultured CaCo-2 cells and medium when cells were incubated with either dealcoholized red wine, alcoholized red wine, or atorvastatin compared with controls. Intracellular cholesterol availability was also attenuated in cells incubated with dealcoholized red wine (72.5%), alcoholized red wine (81.5%), and atorvastatin (83.5%) compared to control cells. Collectively, this study suggests that red wine polyphenolics downregulate the production of atherogenic chylomicrons from intestinal cells, which may explain the reduced CVD mortality rates following its consumption.

Anticholesteremic Agents↗

PubMed2005

Margarine phytosterols decrease the secretion of atherogenic lipoproteins from HepG2 liver and Caco2 intestinal cells.

Several studies in humans have demonstrated the hypocholesterolemic effect of plant sterol consumption. It is unclear whether plant sterols regulate lipoprotein metabolism in the liver and intestines, thereby decreasing the levels of circulating atherogenic lipoproteins. We investigated the effect of the three main phytosterols: stigmasterol, campesterol, and beta-sitosterol on lipoprotein production in HepG2 human liver cells and Caco2 human intestinal cells and the mechanisms involved. Cells were incubated for 24h with 50 micromol/L of the different phytosterols or 10 micromol/L of atorvastatin. Very low-density lipoprotein levels (measured by apolipoprotein (apo) B100) in HepG2 cells and chylomicron levels (measured by apoB48) in Caco2 cells were measured using western blotting. Intracellular cholesterol levels were measured using gas chromatography. Analysis was carried out using Student's t-test and ANOVA. Secretion levels of apoB100 significantly decreased by approximately 30% after incubation with all phytosterols compared to control. In addition, cholesterol ester (CE) concentrations significantly decreased when HepG2 cells were incubated with the phytosterols compared to control cells. Secretion of apoB48 from intestinal cells significantly decreased by 15% with stigmasterol, 16% with campesterol and 19% beta-sitosterol compared to control. Collectively the data suggests that plant sterols limit lipid (CE) availability in cells. Decreases in circulating levels of LDL and chylomicron remnants seen in humans with the consumption of margarine phytosterols are possibly due to their effect on lipid production in cells and would therefore reduce the risk of developing cardiovascular disease.

Anticholesteremic Agents↗

PubMed2005

Conjugated linoleic acid suppresses the secretion of atherogenic lipoproteins from human HepG2 liver cells.

Studies in healthy humans have shown that consumption of conjugated linoleic acid (CLA) significantly reduced very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) blood concentrations. We propose that decreased concentrations are due to the inhibition of VLDL production and secretion [measured by apolipoprotein B100 (apoB100)] from the liver. To investigate the effects of a mixture of CLA isomers on VLDL metabolism, HepG2 liver cells were incubated for 24 h with 50 micromol/L of the different fatty acids. Effects of CLA were compared to a saturated fatty acid (palmitic acid), an n-6 fatty acid (linoleic acid) and no treatment (control). HepG2-cell apoB100 levels were measured using Western blotting. ApoB100 secretion was significantly decreased in cells treated with CLA (44%, p<0.005) compared to control cells and those enriched with palmitic acid. Treatment of cells with CLA also decreased intracellular cholesterol levels. Collectively, these results demonstrate that CLA reduces apoB100 production and secretion compared to saturated and polyunsaturated fatty acids, possibly by limiting the availability of free cholesterol (required for apoB100 production). A reduction in apoB100 production in the body would decrease the levels of VLDL and atherogenic LDL and thus reduce the risk of developing cardiovascular disease.

Apolipoprotein B-100↗