Background Vascular injury results in uncontrollable hemorrhage in hemorrhagic diseases and excessive antithrombotic therapy. Safe and efficient hemostatic agents which can be orally administered are urgently needed. Platelets play indispensable roles in hemostasis, but there is no drug exerting hemostatic effects through enhancing platelet function. Methods The regulatory effects of icaritin, a natural compound isolated from Herba Epimedii, on the dense granule release, thromboxane A2 (TxA2) synthesis, α-granule release, activation of integrin αIIbβ3, and aggregation of platelets induced by multiple agonists were investigated. The effects of icaritin on tail vein bleeding times of warfarin-treated mice were also evaluated. Furthermore, we investigated the underlying mechanisms by which icaritin exerted its pharmacological effects. Results Icaritin alone did not activate platelets, but significantly potentiated the dense granule release, α-granule release, activation of integrin αIIbβ3, and aggregation of platelets induced by thrombin and U46619. Icaritin also shortened tail vein bleeding times of mice treated with warfarin. In addition, phosphorylated proteome analysis, immunoblotting analysis, and pharmacological research revealed that icaritin sensitized the activation of phospholipase Cγ2 (PLCγ2)-protein kinase C (PKC) signaling pathways, which play important roles in platelet activation. Conclusion Icaritin can sensitize platelet activation induced by thrombin and TxA2 through enhancing the activation of PLCγ2-PKC signaling pathways and promote hemostasis, and has potential to be developed into a novel orally deliverable therapeutic agent for hemorrhages.

中文翻译：

---

淫羊藿素通过增强 PLCγ2-PKC 信号通路使凝血酶和 TxA2 诱导的血小板激活变得敏感并促进止血

背景血管损伤导致出血性疾病中无法控制的出血和过度的抗血栓治疗。迫切需要安全有效的口服止血剂。血小板在止血中发挥着不可或缺的作用，但目前还没有药物通过增强血小板功能来发挥止血作用。方法 研究淫羊藿中分离的天然化合物淫羊藿素对致密颗粒释放、血栓素 A2 (TxA2) 合成、α-颗粒释放、整合素 αIIbβ3 激活和多种激动剂诱导的血小板聚集的调节作用。还评估了淫羊藿素对华法林治疗小鼠尾静脉出血时间的影响。此外，我们研究了淫羊藿素发挥其药理作用的潜在机制。结果单独使用淫羊藿素不会激活血小板，但显着增强凝血酶和U46619诱导的致密颗粒释放、α颗粒释放、整合素αIIbβ3激活以及血小板聚集。淫羊藿素还可以缩短接受华法林治疗的小鼠的尾静脉出血时间。此外，磷酸化蛋白质组分析、免疫印迹分析和药理学研究表明，淫羊藿素可敏化磷脂酶Cγ2（PLCγ2）-蛋白激酶C（PKC）信号通路的激活，该信号通路在血小板激活中发挥重要作用。结论 淫羊藿素可以通过增强PLCγ2-PKC信号通路的激活来增敏凝血酶和TxA2诱导的血小板活化，从而促进止血，具有开发成为新型口服出血治疗剂的潜力。