Tetrahydrocurcumin Downregulates MAPKs/cPLA 2 Signaling and Attenuates Platelet Thromboxane A 2 Generation, Granule Secretion, and Thrombus Growth

Platelet granule secretion plays a key role in atherothrombosis. Curcumin, a natural polyphenol compound derived from turmeric, exerts multiple biological activities. The current study sought to investigate the efficacy of tetrahydrocurcumin (THC, the major active metabolite of curcumin) on platelet granule secretion in vitro and thrombus formation in vivo. We found that THC significantly attenuated agonist-induced granule secretion in human gel-filtered platelets in vitro, including CD62P and CD63 expression and platelet factor 4, CCL5, and adenosine triphosphate release. These inhibitory effects of THC were partially mediated by the attenuation of cytosolic phospholipase A (2) (cPLA (2) ) phosphorylation, leading to a decrease in thromboxane A (2) (TxA (2) ) generation. Moreover, the MAPK (Erk1/2, JNK1/2, and p38 MAPK) signaling pathways were downregulated by THC treatment, resulting in reduced cPLA (2) activation, TxA (2) generation, and granule secretion. Additionally, THC and curcumin attenuated murine thrombus growth in a FeCl (3) -induced mesenteric arteriole thrombosis model in C57BL/6J mice without prolonging the tail bleeding time. THC exerted more potent inhibitory effects on thrombosis formation than curcumin. Through blocking cyclooxygenase-1 activity and thus inhibiting platelet TxA (2) synthesis and granule secretion with aspirin, we found that THC did not further decrease the inhibitory effects of aspirin on thrombosis formation. Thus, through inhibiting MAPKs/cPLA (2) signaling, and attenuating platelet TxA (2) generation, granule secretion, and thrombus formation, THC may be a potent cardioprotective agent.

Automated summary

The study found that tetrahydrocurcumin (THC) exerts inhibitory effects on platelet granule secretion and thrombus formation through multiple pathways, potentially serving as an effective cardioprotective agent.