Effect of gamma-oryzanol on the bioaccessibility and synthesis of cholesterol.
Effect of gamma-oryzanol on the bioaccessibility and synthesis of cholesterol.
复制标题
γ-谷维素对胆固醇生物可及性和合成的影响。
DOI：
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复制
发表时间：
2012
影响因子：
3.3
通讯作者：
T. Ariyapitipun
中科院分区：
文献类型：
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作者：
K. Mäkynen;C. Chitchumroonchokchai;S. Adisakwattana;ML. Failla;T. Ariyapitipun
背景和目标
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.