School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, The Co-Innovation Center of Chemistry and Chemical Engineering of Tianjin, Tianjin University, Tianjin, 300072, PR China.
School of Medicine, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.
J Ethnopharmacol. 2022 Feb 10;284:114733. doi: 10.1016/j.jep.2021.114733. Epub 2021 Oct 10.
Kidney stones is one of the common diseases of the urinary system. The primary cause of kidney stone formation is the thermodynamic supersaturation of lithogenic solutes in urine, which desaturates by nucleation, crystal growth and aggregation of minerals and salts, mainly Calcium oxalate (CaOx). One of the potential therapies is to develop drug molecules to inhibit or prevent CaOx crystallization in urine. Traditional Chinese medicines (TCMs) provided an efficient approach for the treatment of kidney stones with a specialized-designed recipe of medicinal herbs. But the action details of these herbs were poorly understood due to their complex components, and whether the effective constituents of herbs have an inhibitory effect on the process of stone formation has not been evaluated.
This study aims to develop and identify inhibitor substitutes from a library of kidney stone prescriptions in traditional Chinese medicines to prevent pathological kidney stone formation.
As many as twenty Chinese medicines were extracted and separated into five different polar extracts, the inhibition performance of which on CaOx crystallization was explored by recording and comparing crystallization kinetics. The potential inhibitor molecules in the inhibitory extracts were confirmed by HPLC and their retardation efficacy was evaluated by quantifying nucleation and growth kinetics using colorimetry. Then the inhibitor-COM crystal interactions and specificity were examined by morphology evolution and surface structure analysis. In vitro inhibition performance of inhibitors on crystal growth and attachment of CaOx crystals to human renal epithelial cells were further evaluated by recording the nucleation and adhesive crystal numbers.
Water- and n-butanol- soluble extracts from 20 kinds of herbs show almost 100% inhibition percentage, and the n-butanol extracts was found better than commercial drug citrate. Twenty-one molecule substitutes were identified from these extracts, and among them polyphenols display the best inhibition efficacy to retard CaOx crystallization. The high-throughput colorimetric assay and morphology examinations reveals thirteen out of 21 molecules show inhibition potential and disrupt growth of CaOx monohydrate crystals by interacting with exposed Ca and CO on the (100) and (010) surfaces. Moreover, these inhibitors also display pronounced performance in protecting renal epithelial cells by inhibiting nucleation and adhesion of CaOx crystals to cells, thus reducing stone formation. The structure-performance correlation among 19 screened molecules that inhibitors having pKa<3.5, logD (pH = 6) <0, H-number>0.1 mmol are the best in suppressing CaOx crystallization. Our findings provide a novel solution to design and manufacture inhibitor drugs from Chinese medicines for preventing pathological kidney stones formation.
肾结石是泌尿系统的常见疾病之一。肾结石形成的主要原因是尿中结石形成溶质的热力学过饱和度，通过成核、晶体生长和矿物质及盐的聚集使饱和度降低，主要是草酸钙（CaOx）。一种潜在的治疗方法是开发抑制或预防尿中 CaOx 结晶的药物分子。中药（TCM）为肾结石的治疗提供了一种有效的方法，专门设计了草药配方。但是，由于其复杂的成分，这些草药的作用细节了解甚少，并且草药的有效成分是否对结石形成过程有抑制作用尚未得到评估。
本研究旨在从中药肾结石处方库中开发和鉴定抑制剂替代物，以预防病理性肾结石的形成。
从 20 种中药中提取并分离成 5 种不同极性提取物，通过记录和比较结晶动力学来探索其对 CaOx 结晶的抑制性能。通过高效液相色谱法（HPLC）确认抑制提取物中的潜在抑制剂分子，并通过比色法量化成核和生长动力学来评估其抑制效果。然后通过形貌演变和表面结构分析研究抑制剂-COM 晶体的相互作用和特异性。通过记录成核和粘附 CaOx 晶体的数量，进一步评估抑制剂对晶体生长和人肾上皮细胞附着的体外抑制性能。
20 种草药的水相和正丁醇相提取物的抑制率几乎达到 100%，正丁醇提取物优于商业药物柠檬酸盐。从这些提取物中鉴定出 21 种分子替代物，其中多酚对延缓 CaOx 结晶显示出最佳的抑制效果。高通量比色法和形貌检查表明，21 种分子中有 13 种具有抑制潜力，并通过与暴露的 Ca 和 CO 在（100）和（010）表面上相互作用来干扰 CaOx 一水合物晶体的生长。此外，这些抑制剂还通过抑制 CaOx 晶体的成核和粘附到细胞，从而减少结石形成，在保护肾上皮细胞方面表现出明显的性能。在 19 种筛选分子中，抑制剂的结构-性能相关性 pKa<3.5、logD（pH=6）<0、H-数>0.1mmol，在抑制 CaOx 结晶方面效果最佳。我们的研究结果为设计和制造用于预防病理性肾结石形成的中药抑制剂药物提供了一种新的解决方案。
