Cattle bile but not bear bile or pig bile induces lipid profile changes and fatty liver injury in mice: Mediation by cholic acid

Three types of animal bile preparation, bear bile (BB), cattle bile (CB) and pig bile (PB) differ in bile acid composition and are supposed to exert different pharmacotoxicological actions. Dietary supplementation with CB at 1% (w/w) for 4 weeks decreased triacylglycerol (TAG) level but increased total cholesterol (CHO) level in serum, which were associated with fatty liver injury in mice. The increased levels of cholesterol esters (CE) and monounsaturated fatty acids (MUFA) in the serum and liver were observed in the mice fed the CB-supplemented diet. Lipid abnormalities and fatty liver injury observed in the mice fed the CB diet were not induced by the supplementation with BB and PB. The supplementation with cholic acid (CA), the most abundant bile acid in CB, could induce lipid abnormalities and fatty liver injury, which were indistinguishable from those induced by CB supplementation. CB and CA supplementation induced similar changes in the expression levels of mRNAs in the liver. Thus, CB induced lipid abnormalities and fatty liver injury, which can be attributed to the actions of CA contained in CB. The inabilities of BB and PB to induce lipid abnormalities and fatty liver injury are supposed to be due to their limited contents of CA.