Zardaverine (BY 290) is an orally available, selective and potent PDE3/4 inhibitor with bronchodilator activity and anti-hepatocarcinogenic activity.Zardaverine's action in platelets is mediated by PDE III isoenzymes and can be used in studies of acute renal failure and chronic airflow obstruction.

Zardaverine selectively inhibits the growth of human hepatocellular carcinoma (HCC) cells in vitro when administered at concentrations ranging from 0 to 30 µM for 72 hours[3].Selective antitumor activity of Zardaverine is observed, closely related to the regulation of cell cycle-associated proteins, but independent of PDE3/4 inhibition[3].At a concentration of 0.1 µM for 24 hours, Zardaverine selectively induces G0/G1-phase arrest and dysregulates cell cycle-associated proteins in HCC cells[3].Zardaverine induces apoptosis in a time- and concentration-dependent manner in Bel-7402 and SMMC-7721 cells. The concentrations used include 0.01, 0.03, 0.1, 0.3, and 1 µM over 48 hours, as well as 0.3 and 1 µM over 24, 36, 48, 60, and 72 hours[3].