Barros M E, Schor N, Boim M A
Nephrology Division, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
Urol Res. 2003 Feb;30(6):374-9. doi: 10.1007/s00240-002-0285-y. Epub 2003 Jan 21.
Phyllanthus niruri is a plant used in Brazilian folk medicine for the treatment of urolithiasis. It was previously observed that P. niruri shows no toxicity, potentially increases calculus voiding by stone forming patients and inhibits the endocytosis of calcium oxalate (CaOx) crystals by MDCK cells. In addition, in a rat model of urolithiasis it reduced calculus growth. In the present study, we evaluated the effect of an aqueous extract of P. niruri on CaOx crystallization in vitro. CaOx precipitation was induced by the addition of 0.1 M sodium oxalate to unfiltered urine samples from Wistar rats (n=14) and normal humans (n=18) in the presence or absence of P. niruri extract (0.25 mg/ml of urine). The presence of CaOx crystals was evaluated immediately and 24 h later. In vitro crystallization of human urine produced typical mono- and dihydrated CaOx crystals, but only a few typical CaOx crystals were found in rat urine. The presence of P. niruri extract did not inhibit CaOx precipitation and even more crystals were obtained, although they were significantly smaller than those in the control urine. Crystal aggregation observed 24 h after crystallization was also inhibited by P. niruri extract. The results showed an inhibitory effect of P. niruri extract on CaOx crystal growth and aggregation in human urine, suggesting that it may interfere with the early stages of stone formation and may represent an alternative form of treatment and/or prevention of urolithiasis
叶下珠是一种用于巴西民间医学治疗尿路结石的植物。此前观察到，叶下珠无毒，可能会增加结石形成患者的结石排出量，并抑制MDCK细胞对草酸钙（CaOx）晶体的内吞作用。此外，在尿路结石大鼠模型中，它能减少结石生长。在本研究中，我们评估了叶下珠水提取物对体外CaOx结晶的影响。在有或没有叶下珠提取物（0.25mg/ml尿液）的情况下，向Wistar大鼠（n = 14）和正常人（n = 18）的未过滤尿液样本中加入0.1M草酸钠，诱导CaOx沉淀。立即和24小时后评估CaOx晶体的存在情况。人尿的体外结晶产生了典型的单水合和二水合CaOx晶体，但在大鼠尿液中仅发现少数典型的CaOx晶体。叶下珠提取物的存在并未抑制CaOx沉淀，甚至获得了更多的晶体，尽管它们明显小于对照尿液中的晶体。结晶24小时后观察到的晶体聚集也受到叶下珠提取物的抑制。结果表明，叶下珠提取物对人尿中CaOx晶体的生长和聚集具有抑制作用，表明它可能会干扰结石形成的早期阶段，可能代表一种治疗和/或预防尿路结石的替代形式。
