Out-Patient Department, Chinese PLA General Hospital, Beijing 100853, China.
Department of Pathophysiology, Chinese PLA General Hospital, Beijing 100853, China ; State Key Laboratory of Kidney Disease, Chinese PLA General Hospital, 2011DAV00088, Beijing 100853, China.
Evid Based Complement Alternat Med. 2014;2014:408501. doi: 10.1155/2014/408501. Epub 2014 Feb 13.
Puerariae Lobatae Radix (Gegen in Chinese) is the dried root of Pueraria lobata, a semiwoody, perennial, and leguminous vine native to China. Puerarin is one of the effective components of isoflavones isolated from the root of Pueraria lobata. Previous studies showed that extracts derived from the root of Pueraria lobata possessed antihypertensive effect. Our study is to investigate whether puerarin contributes to prevention of stroke by improving cerebral microcirculation in rats. Materials and Methods. Video microscopy and laser Doppler perfusion imaging on the pia mater were used to measure the diameter of microvessel and blood perfusion in 12-week old spontaneously hypertensive rats (SHRs) and age-matched normotensive WKY rats. Histological alterations were observed by hematoxylin and eosin staining, and microvessel density in cerebral tissue was measured by immunohistochemical analysis with anti-Factor VIII antibody. Cell proliferation was detected by [(3)H]-TdR incorporation, and activities of p42/44 mitogen activated protein kinases (p42/44 MAPKs) were detected by western blot analysis in cultured cerebral microvascular endothelial cells (MECs). Results. Intravenous injection of puerarin relaxed arterioles and increased the blood flow perfusion in the pia mater in SHRs. Puerarin treatment for 14 days reduced the blood pressure to a normal level in SHRs (P < 0.05) and increased the arteriole diameter in the pia mater significantly as compared with vehicle treatment. Arteriole remodeling, edema, and ischemia in cerebral tissue were attenuated in puerarin-treated SHRs. Microvessel density in cerebral tissue was greater with puerarin than with vehicle treatment. Puerarin-treated MECs showed greater proliferation and p42/44 MAPKs activities than vehicle treatment. Conclusions. Puerarin possesses effects of antihypertension and stroke prevention by improved microcirculation in SHRs, which results from the increase in cerebral blood perfusion both by arteriole relaxation and p42/44 MAPKs-mediated angiogenesis.
葛根（Gegen 在中文中）是豆科植物野葛的干燥根，野葛是一种原产于中国的半木质、多年生藤本植物。葛根素是从野葛根中分离得到的异黄酮的有效成分之一。先前的研究表明，野葛根提取物具有降压作用。我们的研究旨在探讨葛根素是否通过改善大鼠脑微循环来预防中风。
材料和方法。使用视频显微镜和激光多普勒脑皮层微血管血流成像技术，测量 12 周龄自发性高血压大鼠（SHR）和同年龄的正常血压 WKY 大鼠的微血管直径和血流灌注。苏木精和伊红染色观察组织学改变，用抗因子 VIII 抗体的免疫组化分析测量脑组织中的微血管密度。通过 [(3)H]-TdR 掺入检测细胞增殖，通过 Western blot 分析检测培养的脑微血管内皮细胞（MEC）中 p42/44 丝裂原活化蛋白激酶（p42/44 MAPKs）的活性。
结果。葛根素静脉注射可松弛 SHR 大鼠的小动脉并增加软脑膜血流灌注。葛根素治疗 14 天可使 SHR 的血压降至正常水平（P < 0.05），并显著增加软脑膜中小动脉的直径，与对照组相比。葛根素治疗可减轻 SHR 脑组织中的动脉重塑、水肿和缺血。与对照组相比，脑组织中的微血管密度更大。与对照组相比，葛根素处理的 MEC 显示出更高的增殖和 p42/44 MAPKs 活性。
结论。葛根素通过改善 SHR 的微循环具有降压和预防中风的作用，这是通过小动脉松弛和 p42/44 MAPKs 介导的血管生成增加脑血流灌注来实现的。
