发酵麦胚对高脂模型大鼠胆固醇水平的调节

目的:探讨发酵麦胚对高脂模型大鼠胆固醇水平的调节及可能的作用机制。方法:雄性SD大鼠,根据体质量和血清胆固醇水平随机分组,每组10只,空白组自由取食基础饲料和饮水,模型组、液低组、液中组、液高组、渣低组、渣中组、渣高组自由取食高脂饲料和饮水,每天固定时间灌胃,空白组和模型组灌胃同体积水,其他组分别灌胃221、442、884 mg/(kg·d)的发酵液冻干粉和沉淀物冻干粉。60 d后测血清总胆固醇(total cholesterol,TC)含量、高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)含量、肝脏TC含量、胆固醇7α-羟化酶(cholesterol 7α-hydroxylase,CYP7A1)活性、排便量和粪便胆汁酸含量。结果:模型组血清TC含量极显著高于空白组(P0.01),高胆固醇血症模型构建成功;液低组、渣中组大鼠血清TC含量分别显著(P0.05)和极显著(P0.01)低于模型组;各受试组肝脏TC含量、排便量和粪便胆汁酸排出量均高于模型组,但未达显著水平(P0.05)。结论:发酵麦胚降血清胆固醇效果明确,且具有时间效应和剂量效应关系;其作用途径可能与促进血清胆固醇向肝脏转运、增加胆固醇向胆汁酸转化以及增加排便量有关。

Effect of Fermented Wheat Germ on Cholesterol Levels in Rats with Hypercholesterolemia

Objective: To investigate the effect of fermented wheat germ on cholesterol levels in rats with hypercholesterolemia and to elucidate the underlying molecular mechanism. Methods: Male Sprague-Dawley (SD) rats were randomly divided into 8 groups by cholesterol level and body weight. The rats in the control group were fed a normal diet and water, while those in the model were given a high-fat diet and water. The other groups were intragastrically administrated with lyophilized powder of the fermented supernatant at low (LS group, 221 mg/(kg·d)), medium (MS group, 442 mg/(kg·d)) and high (HS group, 884 mg/(kg·d)) doses, and with lyophilized powder of the precipitate at low (LP group, 221mg/(kg·d)), medium (MP group, 442 mg/(kg·d)) and high (HP group, 884 mg/(kg·d)) doses, respectively, all of which were also given a high-fat diet and water. Both the control and model groups received an identical volume of water. The administration lasted for 60 days and at the end of this period, all rats were sacrificed for analysis of serum total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C), liver TC and cholesterol 7α-hydroxylase (CYP7A1), and stool quantity and fecal bile acids (BA). Results: Serum TC level in the rats fed the high-fat diet were significantly increased compared with those fed the normal diet. A rat model of hypercholesterolemia was established successfully. Serum TC levels of the rats in the LS and MP groups were significantly reduced in contrast to those in the model group (P < 0.05 and P < 0.01, respectively). Liver TC concentrations, stool quantity and fecal bile acid levels in all treatment groups were increased, but the differences were not significant statistically compared with the model group (P > 0.05). Conclusion: Fermented wheat germ can time-dependently and dose-dependently reduce serum TC by transferring TC from the serum to the liver, promoting BA formation from TC and increasing stool quantity.