In vitro effect of lemon and orange juices on calcium oxalate crystallization
In vitro effect of lemon and orange juices on calcium oxalate crystallization
复制标题
DOI：
10.1007/s11255-007-9256-0
复制
发表时间：
2008-09-01
影响因子：
2
通讯作者：
Cevik, Cemal
中科院分区：
文献类型：
--
作者：
Kulaksizoglu, Sevsen;Sofikerim, Mustafa;Cevik, Cemal
目的近年来，对泌尿系结石形成过程中的物理化学过程的识别和定量研究取得了重要进展。尿液抑制草酸钙结晶的能力是防止结石形成的重要机制。饮食因素似乎影响尿液抑制草酸钙结晶的能力。这些因素促使我们研究柠檬和橙子汁对草酸钙结晶的影响，在vitro.Material and Methods草酸钙一水合物晶体的成核和聚集进行了研究，使用浊度30分钟的时间过程测量光密度在620 nm后，混合溶液中含有氯化钙和草酸钠在37 ℃，pH 5.7。通过加入草酸盐和钙溶液诱导晶体的形成。研究了柠檬酸三钠、柠檬汁和橙子汁对草酸钙晶体生长的影响。通过添加50 ml果汁来评价柠檬汁和橙子汁的效果。在生理条件下测量光密度。光密度随时间的最大增加，称为S（N），反映了新粒子形成的最大速率。在达到平衡后，观察到光密度随时间逐渐降低。结果在所研究的改性剂中，柠檬酸盐降低了S（N）和S（A）（P < 0.001）。柠檬汁也被发现抑制晶体成核和聚集的速率。结论有效的预防尿结石形成应以恢复尿液抑制草酸钙结晶的能力为目标，并应重视饮食措施。
Aim In recent years significant progress has been made in identifying and quantitating physico-chemical processes involved in urinary stone formation. The ability of urine to inhibit calcium oxalate crystallization is an important mechanism against stone formation. Dietary factors appear to affect the ability of urine to inhibit calcium oxalate crystallization. These factors encouraged us to study the effects of lemon and orange juices on calcium oxalate crystallization in vitro.Material and methods The nucleation and aggregation of calcium oxalate monohydrate crystals were studied using turbidimetric 30-min time course measurements of optic density at 620 nm after mixing solutions containing calcium chloride and sodium oxalate at 37 degrees C, pH 5.7. The formation of crystals is induced by the addition of the oxalate and calcium solution. The effects on calcium oxalate crystal growth of trisodium citrate, lemon and orange juices were examined. The effects of lemon and orange juices were evaluated by the addition of 50 ml of juices. The optical density is measured at physiological conditions. The maximum increase of optic density with time, termed S(N), reflects maximum rate of formation of new particles. After an equilibrium has been reached, a progressive decrease of optic density with time is observed. Rate of aggregation, S(A,) is derived from the maximum decrease in optic density.Results Among the modifiers studied, citrate decreased both S(N) and S(A) (P < 0.001). Lemon juice was also found to inhibit the rate of crystal nucleation and aggregation. But orange juice did not have any effect on the calcium oxalate crystallization (P > 0.05).Conclusion These results show that effective prevention of urinary stone formation should aim at restoring the urine's ability to inhibit calcium oxalate crystallization and more emphasis should be given to dietary measures.