ZLN-024 hydrochloride

ZLN024 allosterically stimulates active AMPK heterotrimers and the inactive α1 subunit truncations α1 (1-394) and α1 (1-335) but not α1 (1-312). AMPK activation by ZLN024 requires the pre-phosphorylation of Thr-172 by at least one upstream kinase and protects AMPK Thr-172 against dephosphorylation by PP2Cα. ZLN024 activates AMPK in L6 myotubes and stimulates glucose uptake and fatty acid oxidation without increasing the ADP/ATP ratio. Using the established scintillation proximity assay (SPA) assay, random screening against the AMPK α1β1γ1 heterotrimer is performed and a new AMPK activator, ZLN024 is found. ZLN024 directly activates recombinant AMPK α1β1γ1 and its homologue α2β1γ1 in a concentration-dependent manner. ZLN024 increases the activity of α1β1γ1 by 1.5-fold and has an EC ₅₀ of 0.42 µM, and it increases the activity of α2β1γ1 by 1.7-fold with an EC ₅₀ of 0.95 µM. ZLN024 also directly activates recombinant AMPK α1β2γ1, by 1.7-fold with an EC ₅₀ of 1.1 µM; and AMPK α2β2γ1, by 1.6-fold with an EC ₅₀ of 0.13 µM.

C57BKS db/db mice are administered a 15 mg/kg/day dose of ZLN024 by daily gavage for 5 weeks; 250 mg/kg/day Metformin (Met) is used as a positive control. During the treatment period, there is no significant alteration in food intake and body weight compared with the vehicle group. After 4 weeks of treatment, ZLN024 improves glucose tolerance. ZLN024 reduces the fasting blood glucose by 15%. Liver tissue weight, triacylglycerol and the total cholesterol content are decreased.