Total steroidal alkaloids from Veratrum patulum L. Inhibit platelet aggregation, thrombi formation and decrease bleeding time in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Veratrum patulum L. (Liliaceae) is used as one source of the Chinese traditional drug "Lilu" which has been used in the treatment of aphasia arising from apoplexy, wind type dysentery, headache, etc. for thousands of years.

AIM OF THE STUDY: To evaluate the antithrombotic effect of Veratrum patulum L. (Liliaceae) total steroidal alkaloids (VpA) and explore the potential mechanisms.

MATERIALS AND METHODS: The antithrombotic effect of VpA was evaluated in two experimental thrombosis models in rat. The potential antithrombotic mechanisms of VpA were explored by determining the coagulation parameters and platelet aggregation induced by various agonists. Cutting-tail rat model was used to evaluate the influence of VpA on bleeding time.

RESULTS: VpA significantly inhibit the formation of arterial and venous thrombosis and showed different inhibitory effect on the platelet aggregation induced by various agonists with the following potency order: collagen>ADP>thrombin. VpA showed no influence on the coagulation parameters in rat. But VpA decreased the cutting-tail bleeding time in rat.

CONCLUSION: VpA possess antithrombotic effect on venous and arterial thrombosis. The antithrombotic effect of VpA is due to its inhibition to platelet aggregation, especially induced by collagen.