裸花紫珠正丁醇提取物止血作用及其机制研究

Hemostatic effects of butyl alcohol extracts from Callicarpa nudiflora via stimulating PI3K/Akt activation on platelets

目的:研究裸花紫珠(Callicarpa nudiflora)正丁醇提取物的止血活性及其可能的作用机制。方法:雌性KM小鼠50只,随机分为空白对照组、云南白药组(1.33g/kg)、裸花紫珠低(0.188 g提取物/kg)、中(0.375g提取物/kg)、高剂量组(0.750g提取物/kg),连续给药3d后测定受试动物的出血时间(Bleeding time,BT)和凝血时间(Clotting time,CT)。取雄性SD大鼠50只,随机分为空白对照组、云南白药组(0.93 g/kg)、裸花紫珠低(0.131g提取物/kg)、中(0.261g提取物/kg)、高剂量组(0.523g提取物/kg),连续给药10d。给药结束后分别测定血小板(Platelet,PLT)计数、二磷酸腺苷(adenosine diphosphate,ADP)诱导的血小板聚集以及血小板中P-选择素(P-Selectin)含量,观察裸花紫珠提取物对血小板数量及活性的影响。采用Western Blot法,检测裸花紫珠提取物对血小板中p-Akt表达的影响。结果:给药后,裸花紫珠正丁醇提取物可显著缩短小鼠的出血时间和凝血时间。与正常组相比,0.131、0.523g裸花紫珠提取物/kg BW均可显著增加大鼠血小板计数。裸花紫珠正丁醇提取物可显著促进ADP诱导的血小板聚集;进一步研究表明,裸花紫珠提取物可显著增加血小板内P-selectin的表达,并促进Akt蛋白的磷酸化。结论:裸花紫珠提取物具有明显的止血作用,促进血小板PI3K/Akt信号转导、刺激血小板的活化可能是其止血作用的机制之一。

Objective： To investigate the hemostatic effects of butyl alcohol extracts from Callicarpa nudiflora （ECN） and its mechanisms. Meth- ods ： KM mice were used to determine the effects of ECN on bleeding time and clotting time, and SD rats were also involved in current study to find out the effects of ECN on count, aggregation induced by adenosine diphosphate （ADP） and P-selectin expression of platelets. In addi- tion, western blot method was involved in current study to detect effects of ECN on activation of Akt signaling pathway. Results： ECN short- ened bleeding time and clotting time of mice significantly （ P 〈 0.01 ）. Moreover, there was a significant increase on platelet by ECN （ P 〈 0. 01）. It was also showed that ECN enhanced platelet aggregation induced by ADP and P-selectin expression on platelets. In addition, ECN stimulated activity of Akt and expression of p-Akt in platelets. Conclusion： ECN shows significant hemostatic properties. Stimulation of platelets activation may be the mechanisms of action of this Traditional Chinese medicine, which is associated with activation of PI3K/Akt signaling pathway in platelets.