Inhibitory effect of tetrahydroberberine on platelet aggregation and thrombosis.

Tetrahydroberberine (THB), an alkaloid extracted from Corydalis ambigua, inhibited the rabbit platelet aggregation triggered by arachidonic acid (AA), ADP, and collagen with IC50 of 0.86, 1.31, and 1.10 mmol.L-1, respectively. THB reduced the thromboxane B2 (TXB2) generation in rabbit platelet-rich plasma triggered by AA. THB 30 mg.kg-1.d-1 ip for 3 or 5 d restrained the ADP-induced platelet aggregation in rats. THB 30 mg.kg-1.d-1 ip for 1, 3, or 5 d inhibited the AA-induced platelet aggregation in rats. THB 15-30 mg.kg-1 iv showed an inhibition of venous thrombosis in rats. The results show that THB is a potent inhibitor of platelet aggregation in vitro and in vivo and is a promising antithrombotic drug.