Novel fatty acid-bile acid conjugates (1a-1k) were designed and synthesized by coupling of the fatty acids to the 3-OH of bile acids using lysine for linkage. In the conjugates, the 24-COOH of the bile acids was kept intact to preserve liver-specific recognition. The ability of the newly synthesized conjugates (at 100 mg/kg dosage) to reduce total cholesterol (TC) and triglyceride (TG) levels in mice fed with high-fat diet (HFD) was evaluated. Conjugates of stearic acid with cholic acid and palmitic acid with ursodeoxycholic acid (at dosages of 50, 100, and 200 mg/kg) were further evaluated to determine their ability to reduce aspartate aminotransferase (AST), alanine aminotransferase (ALT), TC, and TG levels in mice fed with HFD. All conjugates showed potent hypolipidemic activity. Further investigation revealed that compounds 1c and 1 g not only dose-dependently reduced serum levels of TC and TG, but also inhibited the elevation of serum AST and ALT levels in mice fed with HFD. Thus, compounds 1c and 1 g are promising hypolipidemic agents with hepatocyte protective effects against HFD-induced liver damage.
Keywords: Fatty acid; bile acid; conjugate; hypolipidemic; lysine.