Therapeutic Effects of Selaginella tamariscina on the Model of Acute Gout with Hyperuricemia in Rats Based on Metabolomics Analysis

Gout is a disease of purine metabolic disorders which results from long‐term hyperuricemia and the sodium urate deposition in and around the joints. Selaginella tamariscina (ST ) is an important traditional Chinese herbal medicine and is used for the treatment of gout and hyperuricemia. In this study, the rat model of acute gout with hyperuricemia was established by intraperitoneal injection of xanthine and oxonic acid potassium salt and articular injection monosodium urate (MSU ). The effect of ST in the treatment of gout was investigated by measuring joint swelling, the expression of IL ‐1β in serum and histological changes of joint by haematoxylin eosin (H&E) staining. Subsequently, urine metabolomics analysis for biomarkers discovery in acute gout with hyperuricemia rats was performed by the ultra‐performance liquid chromatography‐electrospray ionization quadruple time‐of‐flight mass spectrometry (UPLC‐ESI‐QTOF /MS ) combined with chemometric approach. Principal component analysis (PCA ) and orthogonal partial least squares‐discriminant analysis (OPLS‐DA ) were used to detect potential biomarkers. A total of 18 potential biomarkers were identified mainly including tryptophan metabolism; tyrosine metabolism; lysine methylation; pyrimidine metabolism; purine metabolism; TCA cycle and fatty acid metabolisms. This study indicates that ST could efficiently ameliorate the disease of acute gout with hyperuricemia in rats. The related metabolic biomarkers could provide useful information and the metabolic mechanism could be used for further study about the model of acute gout with hyperuricemia in rats.     

Solubility equilibria in the uric acid-sodium urate-water system

In a constant ionic medium, corresponding to a physiological environment (I_c = 0.15 mol dm⁻³ NaCl), the solubilities of anhydrous uric acid, uric acid dihydrate and monosodium urate monohydrate have been measured as a function of p[H] = −log[H⁺](2-8) and temperature (25°, 32°, 37° and 42°C). The solubility equilibria in the uric acid-sodium urate-water system are discussed on the basis of the solubility constants (K_s) and the first dissociation constant (K₁) of uric acid and the solubility product (K_s0) of monosodium urate. The quantities measured in this work are in good agreement with literature values, however, the present solubility data have a much higher precision.     

Determination of uric acid in human saliva by capillary electrophoresis with electrochemical detection: potential application in fast diagnosis of gout

The clinical manifestations of gout result from the formation and deposition of uric acid (UA) crystals. The monitoring of UA level in less invasive biological samples such as saliva is suggested for diagnosis and therapy of gout, hyperuricemia and the Lesch–Nyhan syndrome. In order to investigate the correlation between trace amounts of UA in human saliva and urine and explore the potential application in fast diagnosis of gout, capillary electrophoresis with electrochemical detection (CE–ED) was applied for the determination of UA in human saliva and urine in this work. Under the optimum conditions, UA and three coexisting analytes could be well separated within 14 min at the separation voltage of 14 kV in 80 mmol L^–1 borax running buffer (pH 7.8). A good linear relationship was established between peak current and concentration of analytes over two orders of magnitude with detection limits (S/N=3) ranging from 1.09×10^–7 to 5.0×10^–7 mol L^–1 for all analytes. This proposed method has been successfully applied for study of the correlation between the UA content of human saliva and urine, providing an alternative and convenient method for rapid diagnosis of gout.     

基于拉伸分子动力学模拟的黄嘌呤氧化酶抑制剂解离途径的理论研究

采用拉伸分子动力学模拟的方法研究了黄嘌呤氧化酶(Xanthine oxidase, XO)抑制剂别嘌呤醇(Allopurinol)和葛根素(Puerarin)从XO离去通道解离的动态过程. 分子对接结果表明, 别嘌呤醇和葛根素均结合在XO的钼蝶呤中心(Molybdopterin, Mo-pt); 丙氨酸扫描的结果显示, Val789, Arg880, Phe911, Phe914和Val1081在XO与抑制剂的结合中起到非常重要的作用. 拉伸分子动力学模拟结果显示, 相比于葛根素, 别嘌呤醇需要更大的外力和更长的时间才能从XO中解离, 拉伸过程中Arg880, Phe1009, Thr1010, Val1011和Ala1079均对维持2种复合物的结构稳定起到重要作用, Phe649和Phe1013在抑制剂解离过程中起到门控的作用, His875起到阻碍抑制剂解离的作用.     

Screening the anti-gout traditional herbs from TCM using an in vitro method

The aim of this work was to evaluate the ability of 33 herbal extracts in inhibiting the acute inflammation and xanthine oxidase(XOD) activity.The anti-inflammation effects of the herbal extracts were detected by an in vitro cell model,which was established by stimulating human umbilical vein endothelial cells(HUVEC) using sodium urate(MSU).In this model,the intercellular adhesion molecule-1(ICAM-1) and interleukin-1 beta(IL-1β) were expressed,and the anti-inflammation effects of herbal extracts were evaluated by detecting the content changes of ICAM-1 and IL-1β in cell lysates and cell culture supernates using an enzyme-linked immunosorbent assay(ELISA).Moreover,an ultrahigh performance liquid chromatography and tandem mass spectrometry(UPLC-MS/MS) method was used for the detection of XOD activity and the screening of XOD inhibitors in this research.The amount of uric acid from each analyte was directly detected using the multiple reaction monitoring mode and the uric acid level could be reduced via the addition of an inhibitor.Results indicated that Salviae Miltiorrhizae Radix et Rhizome,Rhei Radix et Rhizoma,Polygoni Cuspidati Rhizoma et Radix,Selaginellae Herba,Paeoniae Radix Rubra,especially Ginkgo Folium seemed to be more effective in anti-inflammation and inhibiting XOD activity.The anti-inflammation and enzyme inhibitory activities of the herbal extracts may be correlated with their bioactive components.And the differences between the herbal extracts were correlated with the amount of flavonoid and anthraquinone components.In our study,we have investigated the potential anti-inflammation bioactivity of 33 herbal extracts in vitro,which could provide a reference for further in vivo research in the prevention and treatment of gout.