Novel substituted pyrazolone derivatives as AMP-activated protein kinase activators to inhibit lipid synthesis and reduce lipid accumulation in ob/ob mice

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome characterized by hepatic steatosis. NAFLD is closely linked to obesity, insulin resistance and dyslipidemia. AMP-activated protein kinase (AMPK) functions as an energy sensor and plays a central role in regulating lipid metabolism. In this study, we identified a series of novel pyrazolone AMPK activators using a homogeneous time-resolved fluorescence assay (HTRF) based on the AMPKα2β1γ1 complex. Compound 29 (C29) is a candidate compound that directly activated the kinase domain of AMPK with an EC50 value of 2.1–0.2 μmol/L and acted as a non-selective activator of AMPK complexes. Treatment of HepG2 cells with C29 (20, 40 μmol/L) dose-dependently inhibited triglyceride accumulation. Chronic administration of C29 (10, 30 mg/kg every day, po , for 5 weeks) significantly improved lipid metabolism in both the liver and the plasma of ob/ob mice. These results demonstrate that the AMPK activators could be part of a novel treatment approach for NAFLD and associated metabolic disorders.