title: A combination of psyllium and plant sterols alters lipoprotein metabolism in hypercholesterolemic subjects by modifying the intravascular processing of lipoproteins and increasing LDL uptake.
abstract: We previously demonstrated that a diet therapy involving consumption of 7.28 g psyllium (PSY) and 2 g of plant sterols (PS) per day reduced LDL cholesterol from 3.6 +/- 0.7 to 3.1 +/- 0.8 mmol/L (P < 0.01) and decreased the number of intermediate density lipoprotein particles and the smaller LDL and HDL subfractions in hypercholesterolemic individuals (n = 33). The study design was a randomized double blind crossover. Subjects consumed either 2 test cookies containing PSY+PS or 2 placebo cookies for 1 mo with a 3-wk wash out between treatments. To explore mechanisms of the lipid-lowering effects of combined PSY+PS, we present data related to intravascular and molecular regulation. Intake of PSY+PS decreased the cholesterol concentration in LDL-1 from 2.46 +/- 0.66 to 2.26 +/- 0.46 mmol/L and in LDL-2 from 0.63 +/- 0.24 to 0.54 +/- 0.27 mmol/L (P < 0.05) in the test compared with the placebo period. An increase in LDL peak size from 27.3 +/- 0.8 to 27.5 +/- 0.6 nm (P < 0.05) and a decrease in the prevalence of LDL pattern B from 27 to 18% (P < 0.05) also occurred during the PSY+PS period. Cholesteryl ester transfer protein activity was 11% lower (P < 0.05) during the test period. Notably, the abundance of the LDL receptor in circulating mononuclear cells as measured by real time PCR was 26% higher during the test compared with the placebo period (P < 0.03). These results indicate that the hypocholesterolemic action of PSY and PS can be explained in part by modifications in the intravascular processing of lipoproteins and by increases in LDL receptor-mediated uptake.
authors: Department of Nutritional Sciences, University of Connecticut, Storrs, CT 06269, USA.
authors: Sudeep
authors: S
authors: Shrestha
authors: Hedley C
authors: HC
authors: Freake
authors: Mary M
authors: MM
authors: McGrane
authors: Jeff S
authors: JS
authors: Volek
authors: Maria Luz
authors: ML
authors: Fernandez
mesh_terms: D000328:Adult; D000368:Aged; D002784:Cholesterol / Q000097:blood; D053480:Cholesterol Ester Transfer Proteins / Q000037:antagonists & inhibitors / Q000097:blood; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000178:diet therapy* / Q000378:metabolism*; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D010316:Particle Size; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000097:blood; D010840:Phytosterols / Q000008:administration & dosage* / Q000627:therapeutic use; D011620:Psyllium / Q000008:administration & dosage* / Q000627:therapeutic use; D012333:RNA, Messenger / Q000378:metabolism; D011973:Receptors, LDL / Q000097:blood / Q000235:genetics; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: C506642:CETP protein, human; D053480:Cholesterol Ester Transfer Proteins; D004338:Drug Combinations; D000960:Hypolipidemic Agents; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D010840:Phytosterols; D012333:RNA, Messenger; D011973:Receptors, LDL; D011620:Psyllium; D002784:Cholesterol; D007862:Phosphatidylcholine-Sterol O-Acyltransferase