Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-22T11:51:31.508Z Has data issue: false hasContentIssue false
  • English
  • Français

Dietary rhubarb (Rheum rhaponticum) stalk fibre stimulates cholesterol 7α-hydroxylase gene expression and bile acid excretion in cholesterol-fed C57BL/6J mice

Published online by Cambridge University Press:  09 March 2007

Vinti Goel ,
Sukhinder K. Cheema ,
Luis B. Agellon ,
Buncha Ooraikul  and
Tapan K. Basu
Vinti Goel
Affiliation:
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, CanadaT6G 2P5
Sukhinder K. Cheema
Affiliation:
Lipid and Lipoprotein Research Group and Department of Biochemistry, University of Alberta, Edmonton, Alberta, CanadaT6G 2S2
Luis B. Agellon
Affiliation:
Lipid and Lipoprotein Research Group and Department of Biochemistry, University of Alberta, Edmonton, Alberta, CanadaT6G 2S2
Buncha Ooraikul
Affiliation:
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, CanadaT6G 2P5
Tapan K. Basu*
Affiliation:
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, CanadaT6G 2P5
*
*Corresponding author: fax +1 403 492 9130, email tbasu@afns.ualberta.ca
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Both experimental and clinical studies have indicated that a novel source of dietary fibre, produced from rhubarb (Rheum rhaponticum) stalks, is potentially hypolipidaemic. The present study, using C57BL/6J mice, was undertaken to examine if this fibre source affects cholesterol degradation. Mice were maintained on semi-purified diets containing 50 g rhubarb fibre or cellulose/kg with or without 5 g cholesterol/kg for 4 weeks. In cholesterol-supplemented mice, rhubarb fibre caused significant lowering of plasma cholesterol (-13 %) and the hepatic concentrations of total cholesterol (-34 %) and cholesteryl esters (-34 %). In parallel to the reduction of hepatic cholesteryl ester content, animals fed on rhubarb fibre had significantly lower activity of acyl CoA: cholesterol acyltransferase (EC 2.3.1.26) than the mice maintained on a diet containing cellulose and cholesterol. Rhubarb-fibre feeding accelerated the faecal bile-acid loss and diminished the gall-bladder bile-acid pool in both the normal and the cholesterol-fed mice. The increase in the bile-acid excretion was positively correlated with an increased activity as well as mRNA abundance of cholesterol 7α-hydroxylase (EC 1.14.13.17). The increased excretion of bile acids and induction of cholesterol 7α-hydroxylase activity may account for the hypocholesterolaemic effect of rhubarb fibre.

Keywords

Rhubarb (Rheum rhaponticum)Bile acidsCholesterol 7α-hydroxylase
Type
Short communication
Information
British Journal of Nutrition , Volume 81 , Issue 1 , January 1999 , pp. 65 - 71
Copyright
Copyright © The Nutrition Society 1999

References

Abbey, MTriantafilidis, C & Topping, DL (1993) Dietary non-starch polysaccharides interact with cholesterol and fish oil in their effects on plasma lipids and hepatic lipoprotein receptor activity in rats Journal of Nutrition 123, 900–908.CrossRefGoogle ScholarPubMed
Anderson, JWDeakins, DAFloore, TLSmith, BM & Whitis, SE (1990) Dietary fiber and coronary heart disease Critical Reviews in Food Science and Nutrition 29, 95–136.CrossRefGoogle ScholarPubMed
Basu, TKOoraikul, B & Garg, M (1993) The lipid lowering effects of rhubarb stalk fiber: a new source of dietary fiber Nutrition Research 13, 1017–1024.CrossRefGoogle Scholar
Cheema, SKCikaluk, D & Agellon, LB (1997) Dietary fats modulate the regulatory potential of dietary cholesterol on cholesterol 7α-hydroxylase gene expression Journal of Lipid Research 38, 315–323.CrossRefGoogle Scholar
Chomczynski, P & Sacchi, N (1987) Single-step method of RNA isolation by acid guanidium thiocyanate–phenol–chloroform extraction Analytical Biochemistry 162, 156–158.CrossRefGoogle Scholar
Fernandez, ML (1995) Distinct mechanisms of plasma LDL lowering by dietary fiber in the guinea pig: specific effects of pectin, guar gum and psyllium Journal of Lipid Research 36, 2394–2404.CrossRefGoogle ScholarPubMed
Fernandez, MLSun, DMTosca, MA & McNamara, DJ (1994) Citrus pectin and cholesterol interact to regulate hepatic cholesterol homeostasis and lipid metabolism: a dose response study in guinea pigs American Journal of Clinical Nutrition 59, 869–878.CrossRefGoogle ScholarPubMed
Folch, JLees, M & Sloane-Stanley, S (1957) A simple method for the isolation and purification of total lipides from animal sources Journal of Biological Chemistry 226, 497–509.CrossRefGoogle Scholar
Gallaher, DDHassel, CALee, K & Gallaher, C (1993) Viscosity and fermentability as attributes of dietary fiber responsible for the hypocholesterolemic effect of hamsters Journal of Nutrition 123, 244–252.Google ScholarPubMed
Goel, VCheema, SKAgellon, LBOoraikul, BMcBurney, MI & Basu, TK (1998) In vitro binding of bile salt to rhubarb stalk powder Nutrition Research 18, 893–903.CrossRefGoogle Scholar
Goel, VOoraikul, B & Basu, TK (1997) Cholesterol lowering effects of rhubarb fiber in hypercholesterolemic men Journal of the American College of Nutrition 16, 600–604.Google ScholarPubMed
Grogan, WMBailey, MLHueman, DM & Vhahcevic, ZR (1991) Effects of perturbations in hepatic free and esterified cholesterol pools on bile acid synthesis, cholesterol 7α-hydroxylase, HMG CoA-reductase, acyl CoA: cholesterol acyltransferase and cytosolic ester hydrolase Lipids 26, 907–914.CrossRefGoogle ScholarPubMed
Horton, JDCuthbert, JA & Spady, DK (1994) Regulation of hepatic 7α-hydroxylase expression by dietary psyllium in the hamster Journal of Clinical Investigation 93, 2084–2092.CrossRefGoogle Scholar
Kishimoto, YWakabayashi, S & Takida, H (1995) Hypocholesterolemic effect of dietary fiber: relation to intestinal fermentation and bile acid excretion Journal of Nutritional Science and Vitaminology 41, 151–161.CrossRefGoogle ScholarPubMed
Lewis, MCBriecady, LE & Root, C (1995) Effect of 2164U90 on ileal bile acid absorption and serum cholesterol in rats and mice Journal of Lipid Research 36, 1098–1105.CrossRefGoogle ScholarPubMed
Malchow-Moller, AArffmann, SLarusso, NF & Krag, E (1982) Enzymatic determination of total 3α-hydroxy bile acids in faeces Scandinavian Journal of Gastroenterology 17, 331–333.CrossRefGoogle Scholar
Matheson, HBColon, IS & Storey, JA (1995) Cholesterol 7α-hydroxylase activity is increased by dietary modification with psyllium hydrocolloid pectin, cholesterol and cholestyramine in rats Journal of Nutrition 125, 454–458.Google ScholarPubMed
Paigen, BHolmes, PAMitchell, D & Albee, D (1987) Comparison of atherosclerotic lesions and HDL lipid levels in male, female and testosterone treated female mice from strains C57BL/6, BALB/C and C3H Atherosclerosis 64, 215–221.CrossRefGoogle ScholarPubMed
Russel, DW & Setchell, KDR (1992) Bile acid biosynthesis Biochemistry 31, 4737–4748.CrossRefGoogle Scholar
Spector, AAKaduce, TL & Dane, RW (1980) Effect of dietary fat saturation on acyl coenzyme: cholesterol acyltransferase activity of rat liver microsomes Journal of Lipid Research 21, 169–179.CrossRefGoogle Scholar
Steel, RGD & Torrie, JH (1980) Principles and Procedures of Statistics: A Biometrical Approach, pp. 67–119. New York, NY: McGraw-Hill.Google Scholar
Topping, DL (1991) Soluble fiber polysaccharides: effect on plasma cholesterol and colonic fermentation Nutrition Reviews 49, 195–203.CrossRefGoogle ScholarPubMed
Tzung, KWIshimura-Oka, KKihara, SOka, K & Chan, L (1994) Structure of the mouse cholesterol 7α-hydroxylase gene it;Genomics 21, 244–247.CrossRefGoogle Scholar
Zacour, ACSilva, MECecon, PRBambirra, EA & Vieira, EC (1992) Effect of dietary chitin on cholesterol absorption and metabolism in rats Journal of Nutritional Science and Vitaminology 38, 609–613.CrossRefGoogle ScholarPubMed