Effects of baicalein isolated from roots ofScutellaria baicalensis Georgi on interleukin 1β- and tumour necrosis factor α-induced tissue-type plasminogen activator and plasminogen activator inhibitor-1 production in cultured human umbilical vein endothelial cells

Abstract

The effects were examined of baicalein on tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) production stimulated by interleukin-1α (IL-1β) and tumour necrosis factor-α (TNF-α) in cultured human vein umbilical endothelial cells (HUVECs). IL-1β and TNF-α increased PAI-1 production, but they decreased t-PA production. Baicalein isolated from the roots of Scutellaria baicalensis Georgi, inhibited the PAI-1 production stimulated by IL-1β and TNF-α, but it had no effect on the t-PA. In addition, protein kinase C (PKC) inhibitors such as H7 and sphingosine decreased the reduction of t-PA and the increase of PAI-1 by IL-1β and TNF-α. On the other hand, dibutryl cAMP and forskolin had no effect on the t-PA reduction and PAI-1 increase by IL-1β and TNF-α. Moreover, IL-1β and TNF-α did not cause [Ca2+] elevation. These results suggest that the inhibitory action of baicalein on the PAI-1 production by both cytokines might be directly mediated through PKC inhibition. © 1997 John Wiley & Sons, Ltd.