CHIR-99021 shows greater than 500-fold selectivity for GSK-3 versus its closest homologs CDC2 and ERK2, as well as other protein kinases. Furthermore, CHIR-99021 shows only weak binding to a panel of 22 pharmacologically relevant receptors and little inhibitory activity against a panel of 23 nonkinase enzymes. CHIR-99021 induces the activation of glycogen synthase (GS) in insulin receptor-expressing CHO-IR cells with EC50 of 0.763 μM.
In vivo
Oral administration of CHIR-99021 at 30 mg/kg enhances glucose metabolism in a rodent model of type 2 diabetes, with a maximal plasma glucose reduction of nearly 150 mg/dl 3-4 hours after administration, while plasma insulin remains at or below control levels. Oral administration of CHIR-99021 at 16 or 48 mg/kg 1 hour before oral glucose challenges in ZDF rats significantly improves glucose tolerance with 14% and 33% reduction in plasma glucose at 16 mg/kg and 48 mg/kg, respectively, and the higher dose of CHIR-99021 also reduces hyperglycemia before the oral glucose challenge. Cell Data
