Feeding unsaponifiable compounds from rice bran oil does not alter hepatic mRNA abundance for cholesterol metabolism-related proteins in hypercholesterolemic rats

Koji Nagao, Masao Sato, Miyuki Takenaka, Miyuki Ando, Masako Iwamoto, Katsumi Imaizumi

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The hypocholesterolemic effect of rice bran oil (RBO) is defined in human and animal experiments which indicate the presence of active component(s) in the unsaponifiable fraction, but the detailed mechanism is not known yet. Exogenously hypercholesterolemic (ExHC) rats were fed for 2 weeks on a 0.5% cholesterol diet supplemented with 10% each of RBO, RBO-simulated oil (RBOSO) in its fatty acid composition, or RBOSO plus 0.25% unsaponifiable compounds (UC) from RBO. Rats fed RBO or the UC resulted in lowing serum and liver cholesterol concentration and preventing reduction of high density lipoproteinic-cholesterol. Dietary RBO or the UC led to an elevation of fecal neutral sterol excretion, but no significant change in fecal bile acid excretion or in hepatic abundance of mRNAs for 3-hydroxy-3-methylglutaryl-CoA reductase, cholesterol-7α-hydroxylase, and low density lipoprotein receptor. Besides, serum and liver α-tocopherol concentrations were lowered in RBO or the UC-fed rats. These results show that the UC in RBO leads to a decreased serum cholesterol concentration by interrupting the absorption of intestinal hydrophobic compounds rather than by modifying cholesterol metabolism in the liver.

Original languageEnglish
Pages (from-to)371-377
Number of pages7
JournalBioscience, Biotechnology and Biochemistry
Volume65
Issue number2
DOIs
Publication statusPublished - Feb 1 2001

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Analytical Chemistry
  • Biochemistry
  • Applied Microbiology and Biotechnology
  • Molecular Biology
  • Organic Chemistry

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