Red yeast rice increases excretion of bile acids in hamsters.
OBJECTIVE
To investigate the hypocholesterolemic activity of red yeast rice (RYR) and its underlying mechanism.


METHODS
Three groups of hamsters were fed either the control diet or one of the two experimental diets containing by weight 0.1% RYR (0.1RYR) or 0.3% RYR (0.3RYR). Blood (0.5 mL) was collected from the retro-orbital sinus into a heparinized capillary tube at the end of week 0, 3, and 6. Plasma lipoproteins were measured using enzymatic kits, while fecal neutral and acidic sterols were quantified using a gas-liquid chromatography.


RESULTS
Plasma total cholesterol was reduced by 12% in 0.1RYR group and by 18% in 0.3RYR group compared with the control value. Similarly, plasma triacylglycerol was decreased by 11% in 0.1RYR group and by 24% in 0.3RYR group. Western blotting analysis demonstrated that RYR had no effect on sterol regulatory element binding protein 2, liver X receptor, 3-hydroxy-3-methylglutary-CoA reductase, LDL receptor, and cholesterol-7alpha-hydroxylase. HPLC analysis confirmed that RYR contained 0.88% monacolin K. It was recently found that RYR supplementation increased excretion of fecal acidic sterols by 3-4 folds compared with the control value.


CONCLUSIONS
Hypocholesterolemic activity of RYR is mediated at least partially by enhancement of acidic sterol excretion.
Ma
Ka-Ying
KY
Food and Nutritional Sciences Program, Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Zhang
Ze-Sheng
ZS
Zhao
Shu-Xin
SX
Chang
Qi
Q
Wong
Yin-Mei
YM
Yeung
Sai Ying Venus
SY
Huang
Yu
Y
Chen
Zhen-Yu
ZY
D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism*; D001688:Biological Products / Q000494:pharmacology*; D015153:Blotting, Western; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000378:metabolism; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism; D006224:Cricetinae; D019587:Dietary Supplements; D005243:Feces / Q000737:chemistry; D005247:Feeding Behavior / Q000187:drug effects; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D008074:Lipoproteins / Q000097:blood; D008099:Liver / Q000201:enzymology; D000071518:Liver X Receptors; D009281:Naphthalenes / Q000032:analysis; D009929:Organ Size / Q000187:drug effects; D057093:Orphan Nuclear Receptors / Q000378:metabolism; D011973:Receptors, LDL / Q000378:metabolism; D051782:Sterol Regulatory Element Binding Protein 2 / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects
D001647:Bile Acids and Salts; D001688:Biological Products; D008074:Lipoproteins; D000071518:Liver X Receptors; D009281:Naphthalenes; D057093:Orphan Nuclear Receptors; D011973:Receptors, LDL; D051782:Sterol Regulatory Element Binding Protein 2; C117343:red yeast rice; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases; D002790:Cholesterol 7-alpha-Hydroxylase