Format

Send to

Choose Destination
See comment in PubMed Commons below
Eur Rev Med Pharmacol Sci. 2012 Jan;16(1):49-56.

Effect of gamma-oryzanol on the bioaccessibility and synthesis of cholesterol.

Author information

1
The Medical Food Research and Development Center, Department of Transfusion Medicine, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand.

Abstract

BACKGROUND AND OBJECTIVES:

Gamma-oryzanol (gamma-OR) is a unique mixture of triterpene alcohol and sterol ferulates present in rice bran oil. Hypocholesterolemic activity of gamma-OR has been reported in various animal and human studies. However, the mechanisms for this hypocholesterolemic activity of gamma-OR remain unclear. Therefore, the aim of this in vitro study was to examine the effect of gamma-OR on the bioaccessibility and synthesis of cholesterol.

METHODS:

The effects of gamma-OR on the efficiency of incorporation of cholesterol into mixed micelles during digestion and apical uptake of cholesterol by Caco-2 human intestinal cells were determined using the coupled in vitro simulated digestion/Caco-2 human intestinal cell model. The impact of gamma-OR on the HMG-CoA reductase activity was also investigated.

RESULTS:

Although incorporation of cholesterol into synthetic micelles was significantly inhibited by 15-fold molar excess of gamma-OR, efficiency of micellarization of cholesterol during simulated digestion of the rice meal was not significantly altered by the presence of as high as 20-fold molar excess of gamma-OR. Nevertheless, 20-fold molar excess of gamma-OR significantly decreased apical uptake of cholesterol into Caco-2 intestinal cells. In addition, gamma-OR inhibited 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity.

CONCLUSIONS:

These findings suggest that the hypocholesterolemic activity of gamma-OR is due in part to impaired apical uptake of cholesterol into enterocytes and perhaps a decrease in HMG-CoA reductase activity.

PMID:
22338548
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center