Prickly pear (Opuntia sp.) pectin reverses low density lipoprotein receptor suppression induced by a hypercholesterolemic diet in guinea pigs

J Nutr. 1992 Dec;122(12):2330-40. doi: 10.1093/jn/122.12.2330.

Abstract

The effects of prickly pear pectin on plasma LDL metabolism were investigated by feeding guinea pigs either a diet containing 15 g/100 g lard and 0.25 g/100 g cholesterol (LC diet) or the LC diet in which cellulose was partially replaced (2.5 g/100 g) by prickly pear pectin (LC-P diet). The LC-P diet lowered plasma LDL cholesterol concentrations by 33% (P < 0.001). Low density lipoprotein composition was modified by intake of prickly pear pectin; the relative percentages of free and esterified cholesterol were lower and triglycerides were higher in LDL from animals fed the LC-P diet (P < 0.05). Intake of prickly pear pectin did not affect hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase activity; however, hepatic free and esterified cholesterol concentrations were lowered by 46 and 64%, respectively. Hepatic apolipoprotein B/E receptor expression (Bmax) was 60% higher in animals fed the LC-P diet (P < 0.01). Similar to the in vitro data, receptor-mediated LDL fractional catabolic rates were 190% higher in animals fed the LC-P diet (P < 0.05), whereas apolipoprotein LDL flux rates were not affected. Apolipoprotein LDL pool size and fractional catabolic rates exhibited a significant correlation (r = -0.52, P < 0.01). These data indicate that an increase in apolipoprotein B/E receptor expression is a major metabolic response by which intake of prickly pear pectin decreases plasma LDL concentrations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cholesterol / blood
  • Cholesterol / metabolism
  • Cholesterol Esters / blood
  • Cholesterol Esters / metabolism
  • Cholesterol, Dietary / administration & dosage
  • Cholesterol, Dietary / pharmacology*
  • Cholesterol, LDL / blood
  • Guinea Pigs
  • Hydroxymethylglutaryl CoA Reductases / metabolism
  • Liver / drug effects
  • Liver / metabolism
  • Male
  • Pectins / pharmacology*
  • Receptors, Cell Surface / metabolism
  • Receptors, LDL / drug effects*
  • Receptors, LDL / metabolism
  • Receptors, Lipoprotein*
  • Triglycerides / blood

Substances

  • Cholesterol Esters
  • Cholesterol, Dietary
  • Cholesterol, LDL
  • Receptors, Cell Surface
  • Receptors, LDL
  • Receptors, Lipoprotein
  • Triglycerides
  • apolipoprotein B,E receptor
  • Pectins
  • Cholesterol
  • Hydroxymethylglutaryl CoA Reductases