Whole-grain highland hull-less barley (WHLB) contains high amounts of bioactive compounds that potentially exhibit cholesterol-lowering effects. This study investigated the hypocholesterolaemic effect of WHLB. A total of seventy-two male Sprague-Dawley rats were divided into four groups and were fed with the normal control diet, high-fat diet (HFD) and HFD containing low or high dose (10 or 48·95 %) of WHLB. High dose of WHLB significantly decreased the organ indexes of liver and abdominal fat and lipid levels of plasma and liver in HFD rats. The lipid regulation effect of WHLB, which was reconfirmed through hepatocyte morphologic observation, was accompanied by a large excretion of bile acids in the small intestinal contents and the faeces. Real-time PCR analyses, which were further reconfirmed through Western blot analyses, revealed that a high dose of WHLB significantly enhanced the hepatic expressions of AMP-activated protein kinase α, cholesterol 7α-hydroxylase, LDL receptor, liver X receptor, and PPARα and decreased the expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase. It also enhanced the ileal expression of farnesoid X receptor and resulted in the decrease of expression of apical sodium-dependent bile acid transporter. WHLB exhibited hypocholesterolaemic effects mainly by inhibiting cholesterol synthesis, cholesterol accumulation in peripheral tissue, and bile acid reabsorption and by stimulating bile acid synthesis.
Keywords: AMPKα AMP-activated protein kinase α; ASBT apical sodium-dependent bile acid transporter; BC blank control; CYP7A1 cholesterol 7α-hydroxylase; FXR farnesoid X receptor; HD high dose; HFD high-fat diet; HMG-CoAr 3-hydroxy-3-methylglutaryl coenzyme A reductase; IBABP ileal bile acid-binding protein; LD low dose; LDLR LDL receptor; LXR liver X receptor; NC normal control; SREBP-1c sterol regulatory element-binding protein-1c; TC total cholesterol; WHLB whole-grain highland hull-less barley; Cellular biomarkers; Cholesterol metabolism; Dietary fibres; Gene expression; Hull-less barley.