Indirubin-
3’-
oxime is a potent inhibitor of glycogen synthase kinase 3β (GSK3β; IC
50 = 22 nM).
1 As GSK3β phosphorylates tau protein, indirubin-
3’-
oxime prevents tau phosphorylation both
in vitro and
in vivo at Alzheimer’s disease-
relevant sites.
1 It also inhibits cyclin-
dependent kinases (CDKs) at higher concentrations, including Cdk1/cyclin B (IC
50 = 180 nM), Cdk2/cyclin A (IC
50 ~500 nM), Cdk2/cyclin E (IC
50 = 250nM), Cdk4/cyclin D1 (IC
50 = 3.3 μM) and Cdk5/p35 (IC
50 = 100 nM). Indirubin-
3’-
oxime reversibly inhibits the proliferation of many cells types, arresting cycling in the G
2/M phase.
2,3