Cyclocurcumin from Curcuma Tonga selectively inhibits shear stress-induced platelet aggregation

Curcuma longa (C. longa) has been the subject of intensive research for pleiotropic therapeutic potential. However, except for curcumin, the biological activities of other active ingredients of C. longa are not well known. Here, we demonstrated that C. longa extract significantly attenuated shear stress-induced platelet aggregation and cyclocurcumin exhibited the most potent activity (IC50 of 6.33 +/- 3.29 mu M). Cyclocurcumin potently inhibited shear stress-induced platelet activation, primarily through modulating the initial step, vWF - platelets GP Ib interaction. Moreover, cyclocurcumin effectively inhibited thrombus formation, without influencing platelet cell viability or blood clotting time. Collectively, we demonstrated that cyclocurcumin might be a promising therapeutic agent for the treatment or prevention of thrombotic diseases.