A novel selective peroxisome proliferator-activated receptor alpha agonist, 2-methyl-c-5-[4-[5-methyl-2-(4-methylphenyl)-4-oxazolyl]butyl]-1,3-dioxane-r-2-carboxylic acid (NS-220), potently decreases plasma triglyceride and glucose levels and modifies lipoprotein profiles in KK-Ay mice.

2-Methyl-c-5-[4-[5-methyl-2-(4-methylphenyl)-4-oxazolyl]butyl]-1,3-dioxane-r-2-carboxylic acid (NS-220) was newly synthesized and demonstrated to be a novel potent peroxisome proliferator-activated receptor alpha (PPARalpha) agonist with high subtype selectivity. In cell-based reporter gene assays, the EC(50) values of NS-220 for human PPARalpha, PPARgamma, and PPARdelta were 1.9 x 10(-8), 9.6 x 10(-6), and >10(-4) M, respectively, and for mouse PPARalpha, PPARgamma, and PPARdelta were 5.5 x 10(-8), 3.3 x 10(-5), and >10(-4) M, respectively. In addition, [(3)H]NS-220 bound to the ligand-binding domain of human PPARalpha with a K(D) value of 1.85 x 10(-7) M. Fenofibric acid and bezafibrate showed weak agonist activity for PPARalpha (EC(50), 2-8 x 10(-5) M), with poor subtype selectivity. NS-220 (0.1-3 mg/kg p.o.) decreased plasma triglyceride levels in ddY mice in a dose-dependent manner, but its hypolipidemic activity was abolished in PPARalpha-deficient mice. In KK-A(y) mice, an animal model of type-2 diabetes, NS-220 (0.3-1 mg/kg p.o.; 4 days) and fenofibrate (100-300 mg/kg p.o.; 4 days) decreased plasma triglyceride and glucose levels in a dose-dependent manner. In a 2-week repeated administration test, NS-220 (0.3-1 mg/kg p.o.) decreased plasma glucose levels markedly without increasing in plasma insulin levels. Furthermore, NS-220 increased high-density lipoprotein levels and decreased triglyceride-rich lipoprotein levels. In conclusion, a newly synthesized dioxanecarboxylic acid derivative, NS-220, is a potent and highly selective PPARalpha agonist that ameliorates metabolic disorders in diabetic mice. These results strongly suggest that it will be a promising drug for the treatment of hyperlipidemia or metabolic disorders in type-2 diabetes.