title: Lipid components prepared from a freshwater Clam (Corbicula fluminea) extract ameliorate hypercholesterolaemia in rats fed high-cholesterol diet.
abstract: To explore the hypocholesterolaemic components in the fat fraction of freshwater clam extract (FCE), we further fractionated the fat fraction by silica gel column chromatography into nine fat subfractions. In the present study, we used exogenous hypercholesterolaemic rats induced by feeding a high-cholesterol diet; the doses of the added fat subfractions were equivalent to those in 30% FCE. Two (FF1, FF2) out of the nine fat subfractions strongly reduced serum cholesterol levels in the rats fed a high-cholesterol diet. Both FF1 and FF2 up-regulated the hepatic gene expression of cholesterol 7α-hydroxylase, a rate-limiting enzyme of bile acid biosynthesis. Thin-layer chromatography showed that FF1 primarily contained sphingolipids, while FF2 mainly contained triacylglycerols and sterol esters. These results indicate that fractions containing sphingolipids, triacylglycerols, and sterol esters are possibly responsible for the hypocholesterolaemic action in a novel manner through the up-regulation of the hepatic biosynthesis of bile acids.
authors.affiliation: Sasaki Food Company, Limited, 276 Sakai, Bungotakada, Oita 879-0615, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Chijimatsu
authors.forename: Miki
authors.initials: M
authors.lastname: Umeki
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Kataoka
authors.forename: Satoru
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Koji
authors.initials: K
authors.lastname: Yamada
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Oda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mochizuki
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D002784:Cholesterol / Q000378:metabolism*; D002790:Cholesterol 7-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects; D006801:Humans; D006937:Hypercholesterolemia / Q000178:diet therapy* / Q000235:genetics / Q000378:metabolism; D008055:Lipids / Q000008:administration & dosage* / Q000737:chemistry / Q000302:isolation & purification; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012758:Shellfish / Q000032:analysis*
chemical_list: D008055:Lipids; D002784:Cholesterol; C532838:CYP7A1 protein, rat; D002790:Cholesterol 7-alpha-Hydroxylase