目的研究泽泻有效部位对大鼠肾草酸钙结石形成和肾组织骨桥蛋白(OPN)表达的影响,探讨泽泻抑制尿结石形成的机制。方法采用现代植化和生物活性导向分离的方法分离、提取泽泻的有效部位。将30只大鼠随机分成3组对照组、模型组、泽泻组。以乙二醇和1α-羟基维生素D₃ig制备大鼠肾草酸钙结石模型。检测各组大鼠血及尿生化、肾Ca²⁺水平、24h尿草酸分泌量和肾组织病理学改变,并采用免疫印迹(Western blotting)和半定量逆转录聚合酶链反应(RT-PCR)分别观察各组大鼠肾组织OPN蛋白及其mRNA的表达水平。结果ig泽泻有效部位(主要以四环三萜类化合物为主)大鼠的血清肌酐(SCr)、尿素氮(BUN)、肾Ca²⁺水平、24h尿Ca²⁺分泌量、肾组织草酸钙晶体的分布、OPN蛋白及其mRNA的表达水平均显著低于模型组(＜0.01)。结论泽泻有效部位能抑制大鼠肾组织OPN的表达,减少肾组织草酸钙结晶的沉积,从而能有效抑制大鼠肾草酸钙结石的形成。

Objective To study the effects of active fractions of Alisma orientale on urinary calcium oxalate stone formation and osteopontin (OPN) expression in urolithiasis model rats and to explore the mechanism of A. orientale on the prevention of the formation from urinary calculi. Methods The active fractions of A. orientale were seperated and extracted with isolation techniques guided by modern phytochemistry and bioactivity. Adult male Wistar rats (30) were randomized into three groups, they were control, model, and A. orientale groups. The model rats with renal calcium oxalate stone formation were induced by ig ethylene glycol and 1α-hydroxyvitamin D₃ for four weeks. The calcium oxalate deposit in the kidney was observed by microscopy. The SCr and BUN levels, renal tissue calcium content, 24 h urinary oxalic acid excretion, and physiological change in renal tissue were also detected. Western blotting and RT-polymerase chain reaction (RT-PCR) techniques were used to observe the protein and mRNA expression of OPN in rat renal tissue of every groups. Results SCr and BUN level, renal tissue calcium content, 24 h urinary calcium excretion, crystal deposition, and the OPN expression in the rats by ig active fractions which were identified as tetracyclic triterpenoids, were significantly lower than those in model group (P0.01=. Conclusion The active fractions of A. orientale can inhibit the OPN expression and deposit of calcium oxalate in renal tissue so as to block the formation of renal calcium oxalate stone in rats potently.

国家自然科学基金资助项目(39970891)