Piceatannol, a Syk-selective tyrosine kinase inhibitor, attenuated antigen challenge of guinea pig airways in vitro

Activation of nontransmembrane protein tyrosine kinases, such as Lyn and Syk, has been shown to be the earliest detectable signaling response to Fc receptor (FcεRI) cross-linking on mast cells leading to mast cell degranulation. The present study examined the effects of piceatannol (3,4,3′,5′-tetrahydroxy- trans-stilbene, 10–100 μM), a Syk-selective tyrosine kinase inhibitor, on ovalbumin-induced anaphylactic contraction of isolated guinea pig bronchi and release of histamine and peptidoleukotrienes from chopped lung preparations. Pretreatment with piceatannol slightly suppressed ovalbumin-induced peak anaphylactic bronchial contraction but markedly ( P