3,5,2',4'-Tetramethoxystilbene, a fully methylated resveratrol analog, prevents platelet aggregation and thrombus formation by targeting the protease-activated receptor 4 pathway.

Thrombin is a potent platelet activator and a key mediator of blood coagulation, thereby playing a crucial role in cardiovascular disease. Recently, protease-activated receptor 4 (PAR4), one of thrombin receptors in human platelets, is emerging as a promising target for antiplatelet therapy. 3,5,2',4'-Tetramethoxystilbene (TMS), a resveratrol analog, have demonstrated promising effects on preventing atherosclerosis and hypertension, whereas its antiplatelet effect has never been investigated. Herein we show that TMS at concentrations of a few micromolar selectively inhibits PAR4-mediated human platelet aggregation, ATP secretion, integrin αIIbβ3 activation, and signaling pathways. In a whole-blood model of arterial flow, TMS also significantly reduced in vitro thrombus formation. Analysis of the structure-activity relationships of TMS and a panel of stilbene analogs reveal that full methylation of hydroxy groups of the stilbenes is the critical structural determinant for the anti-PAR4 activity. Our results suggest that fully methylated resveratrol analogs with anti-PAR4 activity are potential candidates for development of novel antiplatelet agents.