[Effects of wheat bran fiber on lipid metabolism in ApoE~(-/-) mice].

OBJECTIVE: To explore the effect and mechanism of wheat bran fiber on lipid metabolism in ApoE~(-/-)mice fed a high fat diet. METHODS: Twenty 7-week-old male ApoE~(-/-)mice were randomly divided into two groups and fed either a high fat diet as AS model group or a high fat diet adding 0. 8% wheat bran fiber as W-fiber group. And five C57 BL/6 mice with the same genetic background were used as control group. After 18 weeks feeding, HE staining were performed for atherosclerotic lesions from transverse section of the aorta and hepatic histological examination. Liver homogenate total cholesterol(TC), triglyceride(TG)and free fatty acids(FFAs)were analyzed. Western blot was used to determine the protein expressions involved in hepatic lipid metabolism, including sterol regulatory element binding protein 1(SREBP-1), fatty acid synthase(FAS), acetyl-coA carboxylase(ACC), sterol regulatory element binding protein 2(SREBP-2), low-density lipoproteins receptor(LDLR) and scavenger receptor B1(SR-B1). RESULTS: At the end of the experiment, compared with control group, atherosclerotic plaque of the aorta and hepatic steatosis was obvious in the mice of AS model group, and wheat bran fiber alleviated the area of atheromatous plaque and hepatic lipid accumulation. Compared with AS model group, wheat bran fiber decreased liver homogenate TC level((60. 56±13. 49) μmol/g vs. (51. 10±5. 94) μmol/g)(P<0. 05), reduced protein expression of SREBP-1, FAS and ACC(P<0. 05), increased protein expression of SREBP-2SR-B1(P<0. 05). CONCLUSION: Taken together, wheat bran fiber can delay the occurance of AS by regulating the related protein expressions involved in lipid metabolism and improving hepatic lipid metabolism.