2​ Biological Activity Flavopiridol hydrochloride is a potent cyclin-dependent kinases inhibitor with an IC50 of 100 nM. Preclinically, flavopiridol is the first cyclin-dependent kinase inhibitor. At the nanomolar concentrations, flavoporidol hydrochloride prevented rhabdoid cell growth with an IC50 ranging from 50 to 200 nM. Meanwhile, flavopiridol hydrochloride induced G1 and G2 arrest and apoptosis in vitro in a concentration-dependent manner. These influences were associated with the down- regulation of cyclin D1, up- modulation of p21, and induction of caspase 3/7 activities. At a dose of 7.5 mg/kg, flavopiridol markedly suppress the growth of xenografted rhabdoid tumors. That was associated with the induction of p21 and downregulation of cyclin D1. [1][2] Treatment of flavopiridol decreased the activities of CDK2 and potently prevented cell proliferation with an IC50 ranging from 43 to 83 nM in HNSCC cells. [3] 3​ References: Flavopiridol, the first cyclin-dependent kinase inhibitor to enter the clinic: current status. Kelland LR et al. Expert Opin Investig Drugs. 2000 Dec;9(12):2903-11. Rhabdoid tumor growth is inhibited by flavopiridol. Smith ME et al. Clin Cancer Res. 2008 Jan 15;14(2):523-32. The pharmacological and toxicological properties of this product have not been fully investigated. Exercise caution in use and handling. This product must not be used in humans.