玉米须提取液对尿液中草酸钙晶体形成的影响

本文采用X射线衍射(XRD)、红外光谱(FTIR)、扫描电子显微镜(SEM)等方法分析了玉米须提取液对正常人尿液中草酸钙晶体形成的影响，通过电导率法研究了草酸钙晶体生长的动力学过程，以及从生物矿化的角度对玉米须提取液影响尿液中草酸钙晶体的可能机理进行了探讨。由于玉米须提取液中有机酸或多糖的羟基、羰基等通过配位作用与Ca²⁺结合形成可溶性配位化合物，减少了Ca²⁺与Oxa^2-的结合能力，从而抑制了CaOxa的成核和生长。同时，可能由于玉米须提取液中有效成分与二水草酸钙(COD)的吸附点键合，增强了COD晶体在溶液中的热力学稳定性，进而抑制了COD晶体向热力学更稳定态的一水草酸钙(COM)晶体转变。结果显示，这种抑制作用随玉米须浓度增大而增大，且COD晶体尺寸随着玉米须浓度的增大而减小。玉米须抑制COD晶体向COM晶体转变的作用为开发预防和治疗尿结石的药物提供了启示。

Effect of Corn Silk Extract on the Growth of Calcium Oxalate Crystal in Urines

In this paper, the effect of corn silk extract on the formation of calcium oxalate crystal in healthy urines was studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and the growth process of calcium oxalate crystal was monitored by conductivity instrument. The mechanism of the corn silk extract on the calcium oxalate crystal nucleation and growth was discussed from point of view of biomineralization. The hydroxy and carbonyl of organic acid or polysaccharide existed in corn silk extract can combine with Ca²⁺ by the coordination interaction, resulting in the weaking of binding interaction between Ca²⁺ and Oxa^2-, which restrains the nucleation and growth of CaOxa crystal. The change from calcium oxalate dehydrate (COD) to calcium oxalate monohydrate (COM), which exhibits high thermodynamic stability, can also be restrained due to the binding action of the surface of COD and organic nolecules. The results indicated that the corn silk extract could not only prohibit the transformation of calcium oxalate monohydrate (COM) to calcium oxalate dehydrate (COD), but also reduce the size of COD. This work may provide an opportunity to enrich the medication of urine stone.