[Active constituents in compound whole grain and its regulation on bile acids metabolism].
OBJECTIVE
To analyze and compare the contents of dietary fiber, resistant starch, flavonoid and total saponins in the compound whole grain, to observe the effects of compound whole grain on the excretion of bile acid and its regulation mechanisms.


METHODS
The contents of dietary fiber, resistant starch, flavonoid and saponins in compound whole grain were determined according to the national standard methods and other methods in literatures. Forty-four SPF grade SD rats were allocated randomly into four groups: the negative control group, hyperlipemia model group, rice-flour group and compound whole grain group, and each group was provided with corresponding diet for 8 consecutive weeks. The excrements of rats were collected at the beginning and the ending of the experiment by using metabolic cages. The expression of CYP7A1 mRNA and LXRalphamRNA were also observed.


RESULTS
The composition of compound whole grain was dietary fiber 15.3g, resistant starch 9.03g, flavonoid 0.45g and saponins 0.24g per 100g. The excretion of bile acid was increased significantly (P < 0.05), and the expression of CYP7A1 mRNA and LXRalphamRNA was significantly higher in the compound whole grain group than the other three groups (P < 0.05).


CONCLUSIONS
Compound whole grain is rich in DF, RS, flavonoid and saponins than common flour and rice. The expression of rate-limiting enzyme CYP7A1 mRNA in the classical pathway of bile acid synthesis and its upstream acceptor LXRalpha mRNA could be up-regulated by compound whole grain, thus effectively increasing bile acid excretions, and improving the disorders of lipid metabolism.
Department of Nutrient and food Hygiene, School of Public Health, Southeast University, Nanjing 210009, China. tanqin0813@163.com
Qin
Q
Tan
Chengkai
C
Zhai
Yanbo
Y
Guo
Shufen
S
Han
Jing
J
Chi
Hua
H
Xing
D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism*; D004032:Diet; D004043:Dietary Fiber; D002523:Edible Grain; D006949:Hyperlipidemias; D050356:Lipid Metabolism; D012275:Oryza; D051381:Rats; D012503:Saponins
D001647:Bile Acids and Salts; D004043:Dietary Fiber; D012503:Saponins