Citrus pectin and cholesterol interact to regulate hepatic cholesterol homeostasis and lipoprotein metabolism: A dose-response study in guinea pigs

• Published in: The American journal of clinical nutrition Vol. 59; no. 4; pp. 869 - 878
• Main Authors: Fernandez, ML, Sun, DM, Tosca, MA, McNamara, DJ
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01-04-1994; American Society for Clinical Nutrition; American Society for Clinical Nutrition, Inc
• Subjects: ACILTRANSFERASA; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; ACYLTRANSFERASE; AGRUME; Animals; Biological and medical sciences; CHIMIORECEPTEUR; CHOLESTEROL; Cholesterol - metabolism; Cholesterol, Dietary - pharmacology; Cholesterol, LDL - drug effects; Cholesterol, LDL - metabolism; COBAYA; COBAYE; COLESTEROL; Diet; Dietary Fiber; Dose-Response Relationship, Drug; Drug Interactions; ESTER; ESTERES; Feeding. Feeding behavior; FOIE; FRUTAS CITRICAS; Fundamental and applied biological sciences. Psychology; Guinea Pigs; HIGADO; Homeostasis - drug effects; Hydroxymethylglutaryl CoA Reductases - analysis; Lipid Metabolism; LIPOPROTEINAS; LIPOPROTEINE; Lipoproteins - drug effects; Lipoproteins - metabolism; Liver - drug effects; Liver - enzymology; Liver - metabolism; Low Density Lipoprotein Receptor-Related Protein-1; Male; Metabolism; METABOLISME DES LIPIDES; METABOLISMO DE LIPIDOS; Nutrition; PECTINAS; PECTINE; Pectins - pharmacology; QUIMIORECEPTORS; Receptors, Lipoprotein - analysis; Sterol O-Acyltransferase - analysis; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Liver; Interaction; Rodentia; Rutaceae; Pectin; Lipoprotein; Metabolism; Cholesterol; Feeding; Dose activity relation; Citrus; Vertebrata; Mammalia; Guinea pig; Diet; Dicotyledones; Animal; Angiospermae; Spermatophyta
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/59.4.869

Guinea pigs were fed increasing concentrations of citrus pectin (CP) (0–12.5%, wt/wt) with low (LC, 0.04%) or high (HC, 0.25%) cholesterol. Animals fed LC diets had reduced plasma LDL concentrations with 10% and 12.5% CP and hepatic membrane apolipoprotein B/E receptor expression increased with high dosages of CP. Hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity increased with 12.5% CP whereas hepatic cholesterol concentrations and acyl-CoAxholesterol acyltransferase (ACAT) activity were not different. In contrast, with HC diets, plasma LDL concentrations were reduced in a dose-response manner by 29%, 30%, and 67% with 7.5%, 10%, and 12.5% CP intake (P < 0.001) and apolipoprotein B/E receptor number was increased and inversely correlated with plasma LDL in the HC group (r = −0.81,P < 0.005). Animals fed HC diets had a dose-dependent decrease in hepatic cholesterol and ACAT activity, with intake of 12.5% CP having the major effect. Hepatic HMG-CoA reductase activity was suppressed by HC diets and only intake of 12.5% CP reversed this suppression. The most significant effects of CP on hepatic cholesterol, enzymes of hepatic cholesterol homeostasis, and the apolipoprotein B/E receptor were in animals fed the HC diets. These metabolic alterations partially explain the reduced plasma LDL of guinea pigs fed large amounts of CP.