姜黄降尿酸作用的实验研究

采用次黄嘌呤和氧嗪酸钾诱导的小鼠高尿酸模型,分别给予不同剂量姜黄醇提物,以小鼠血清尿酸(SUA),肝脏黄嘌呤氧化酶活性(XOD),尿液尿酸(UUA)排泄量等为指标。结果,姜黄高剂量醇提物具有显著的降低SUA、抑制XOD活性、促进UUA排泄量的作用。表明姜黄可通过抑制尿酸生成与促进尿酸排泄的双重途径而达到降低血清尿酸。     

茶多酚对高尿酸血症小鼠尿酸产生与排泄的影响及机制研究

目的观察茶多酚(green tea polyphenols,GTP)对氧嗪酸钾(PO)诱导的高尿酸血症(HUA)小鼠血尿酸水平的影响,并从调节尿酸产生和排泄途径探讨其药理机制。方法每天分别灌胃给予PO(250 mg·kg~(-1))和GTP(150、300、600mg·kg~(-1)),连续7 d。磷钨酸法检测小鼠血尿酸水平,比色法和Western blot法分别检测肝脏黄嘌呤氧化酶(XOD)活性与表达,免疫组织化学染色法检测肾脏中尿酸盐转运子1(URAT1)、有机阴离子转运子(OAT)1和3的表达。结果GTP明显降低了氧嗪酸钾诱导的HUA小鼠血尿酸水平(P<0.05或P<0.01);同时,GTP明显降低了HUA小鼠肝脏XOD的活性和表达(P<0.05或P<0.01);此外,GTP还明显降低了HUA小鼠肾脏URAT1的表达,增强了OAT1和OAT3的表达(P<0.05或P<0.01)。结论 GTP对PO诱导的HUA小鼠血尿酸水平有明显降低作用,其机制与减少尿酸产生和增加尿酸排泄密切相关。     

金苓痛风舒微丸对高尿酸血症小鼠血尿酸、肌酐、尿素氮及黄嘌呤氧化酶活性的影响

目的研究金苓痛风舒微丸对高尿酸血症小鼠的血尿酸(blood uric acid,BUA)、肌酐(creatinine,Cr)、尿素氮(blood urea nitrogen,BUN)、黄嘌呤氧化酶(xanthine oxidase,XOD)活性的影响,探讨其治疗痛风的机制。方法采用化学诱导剂氧嗪酸钾盐腹腔注射建立高尿酸血症小鼠模型,药物组分别灌服不同剂量金苓痛风舒微丸,1日1次,连续7d。末次给药1h后,取血,分离血清,采用ELISA法测定小鼠血清BUA、Cr和BUN;取肝脏组织检测XOD的活性。结果金苓痛风舒微丸高、中剂量能显著地降低高尿酸血症小鼠BUA、Cr和BUN的水平(P<0.01),高剂量显著抑制肝脏XOD的活性(P<0.01),中剂量也可明显降低XOD活性(P<0.05)。结论金苓痛风舒微丸的作用机制可能是通过增强肾血流量以及抑制尿酸的分解协同完成的。     

黄嘌呤氧化酶抑制剂筛选体系的建立

目的建立黄嘌呤氧化酶(xanthine oxidase, XOD)抑制剂筛选体系。方法应用理化法,测定体外XOD活性、血尿酸、血清XOD活性、组织XOD活性及肝肾功能有关血液指标;病理分析肝脏肾脏的损伤情况。结果选择牛奶来源XOD 3 U·L~(-1),黄嘌呤(Xanthine, XA) 50μmol·L~(-1),37℃,pH 7.4, 20 min为XOD抑制剂体外高通量筛选的最适条件。单次灌胃次黄嘌呤联合皮下注射氧嗪酸钾诱导ICR小鼠,血尿酸水平一过性升高;以血尿酸变化曲线和血尿酸-时间曲线下面积评价急性高尿酸血症小鼠模型。ICR小鼠连续皮下注射氧嗪酸钾血尿酸平稳升高,成模率约70%;以血尿酸水平评价慢性高尿酸血症小鼠模型。上述2种模型动物的血清和组织XOD活性均未见明显变化,肝脏肾脏均未见明显损伤。结论 XOD抑制剂体外筛选方法与急性高尿酸血症小鼠模型、慢性高尿酸血症小鼠模型等体内实验方法相互验证,形成基于分子靶点XOD的抗高尿酸血症药物研发的实验体系。     

南极磷虾肽改善高尿酸血症机制研究

目的 探究南极磷虾肽(AKP)对于高尿酸血症模型小鼠的降尿酸功效及其作用机制。方法 采用HPLC法体外筛选出具尿酸合成关键限速酶--黄嘌呤氧化酶(Xanthine oxidase, XOD)抑制活性的AKP,体内动物实验验证AKP的降尿酸活性。雄性SPF级Balb/c小鼠采用高嘌呤饲料(25%酵母浸粉)喂养联合腹腔注射尿酸酶抑制剂(氧嗪酸钾,200 mg.kg^-1.BW^-1)建立高尿酸血症小鼠模型,造模21天后进行AKP干预。小鼠随机分为正常对照组(生理盐水),模型对照组(生理盐水)、阳性药组(非布司他)、AKP低剂量组(450 mg.kg^-1.BW^-1),AKP高剂量组(900 mg.kg^-1.BW^-1),干预30天后检测血清尿酸含量(Uric acid, UA),肝脏尿酸合成关键酶酶活,肾脏及肠道尿酸转运蛋白mRNA的转录水平及形态学改变。结果 AKP体外XOD抑制率可达24.4%。动物实验验证表明AKP可显著降低高尿酸模型小鼠的UA,作用机制为通过抑制肝脏尿酸合成关键酶XOD及腺苷脱氨酶(Adenosine Deaminase, ADA)酶活,从而抑制肝脏尿酸生成;上调肾脏及肠道尿酸分泌转运体三磷酸腺苷结合盒转运蛋白(ATP binding cassette superfamily G member 2, ABCG2)、有机阴离子转运体(organic anion transporter 1, OAT1)转录水平,并抑制尿酸重吸收转运体葡萄糖转运体9(glucose transporter 9, GLUT9)、尿酸转运体1(urate transporter 1, URAT1)转录水平,从而促进肾脏及肠道尿酸排泄。AKP可显著降低血清尿素氮(Blood urea nitrogen, BUN)含量,肾脏及肠道切片观察结果进一步表明,AKP可以显著改善高尿酸血症造成的肾脏及肠道损伤,维护肾脏及肠道尿酸排泄功能。结论 AKP可通过抑制肝脏尿酸生成,促进肾脏及肠道尿酸排泄,维护肾脏及肠道形态及功能,从而改善高尿酸血症。     

丹参降尿酸作用初步实验研究

目的研究丹参醇提物对高尿酸血症小鼠尿酸水平的影响,并初步探讨其作用途径。方法腹腔注射黄嘌呤和氧嗪酸钾,诱导小鼠致高尿酸血症,分别给予不同剂量的丹参醇提物,检测小鼠血清尿酸(SUA),尿液尿酸(UUA)及肝脏黄嘌呤氧化酶活性(XOD)。结果丹参中剂量组(DM)和低剂量组(DL)均能显著降低小鼠SUA水平,促进UUA排泄。结论丹参醇提物可通过促进尿酸排泄显著降低小鼠血尿酸水平。     

复方芪苓配方颗粒治疗大鼠高尿酸血症的作用机制研究

目的 研究复方芪苓配方颗粒对高尿酸血症大鼠的降尿酸作用,并从尿酸排泄途径探讨其作用机制。方法 SD大鼠随机分为正常组、模型组、苯溴马隆组、复方芪苓配方颗粒高、中、低剂量组(9.6,4.8,2.4 g·kg-1),通过腺嘌呤灌胃及氧嗪酸钾皮下注射建立高尿酸血症模型,连续给药14 d。分别测定血清尿酸、肌酐、尿素、尿尿酸水平,计算肾脏尿酸清除率。采用RT-PCR方法分别测定动物肾脏中相关转运体的表达水平;观察肾组织病理改变。结果 与模型组比较,复方芪苓配方颗粒组高尿酸血症大鼠的血清尿酸、肌酐、尿素水平显著降低,其肾脏尿酸清除率显著升高;其肾组织病理改变显示,肾小管内尿酸盐结晶减少,肾小管-间质损伤较轻。复方芪苓配方颗粒可以显著下调肾脏尿酸盐转运体1(URAT1)、葡萄糖转运蛋白9(GLUT9) mRNA的表达,上调有机阴离子转运体1(OAT1) mRNA的表达。结论 复方芪苓配方颗粒能降低高尿酸血症大鼠的血清尿酸水平并减轻肾组织病理损害,其作用机制可能是通过调节尿酸转运体的表达水平,以降低肾脏尿酸盐重吸收能力、增加尿酸盐分泌,从而促进尿酸排泄。     

短穗兔耳草提取物对高尿酸血症小鼠肾脏保护作用研究

目的 研究短穗兔耳草提取物对高尿酸血症小鼠肾脏有无保护作用。方法 以氧嗪酸钾盐诱导小鼠高尿酸血症模型为实验系统,通过检测血清尿酸和黄嘌呤氧化酶含量和肾脏病理病变等指标,评价短穗兔耳草提取物对高尿酸血症小鼠肾脏的保护作用。结果 短穗兔耳草可显著降低模型大鼠血清、尿酸和黄嘌呤氧化酶含量, 改善了小鼠肾脏结构的变化。结论 短穗兔耳草具有降尿酸活性及肾脏保护作用。     

金钱草及其民间混用品种对高尿酸血症小鼠的效用

目的研究金钱草及其民间混用品种对高尿酸血症小鼠的效用。方法选择化学诱导剂氧嗪酸钾盐作为尿酸酶抑制剂，腹腔注射造成小鼠高尿酸血症模型。将金钱草及其混用品种水提取物灌胃给药，持续4d。采用磷钨酸法测定小鼠血清尿酸水平。结果水提取物能显著地减少高尿酸血症小鼠的血清尿酸水平。结论金钱草及其混用品种水提取物对高尿酸血症小鼠具有降低血清尿酸水平的效用。     

车前子醇提物与毛蕊花糖苷对实验性高尿酸血症小鼠的比较研究

目的比较毛蕊花糖苷及含相同量毛蕊花糖苷的车前子醇提物对小鼠急性高尿酸血症血尿酸水平的影响,探讨车前子降尿酸主要物质基础。方法将90只小鼠随机分为空白组、高尿酸血症模型组、别嘌醇(10 mg·kg~(-1))组,车前子低、中、高剂量组,毛蕊花糖苷低、中、高剂量组,每组10只,以不同剂量车前子醇提物(4.2、8.4、16.8 g·kg~(-1))及毛蕊花糖苷(0.05、0.10、0.20 g·kg~(-1))连续灌胃7 d,于最后1次给药前1 h采用氧嗪酸钾盐诱导高尿酸血症模型。检测血清尿酸、肌酐(CRE)和尿素氮(BUN)含量及肝脏黄嘌呤氧化酶(XOD)活性,RT-PCR法测定肾脏尿酸转运体mURAT1、m GLUT9、mOAT1mRNA表达。结果与车前子醇提物相比,相同生药量毛蕊花糖苷降尿酸率达到车前子醇提物的67.8%~85.2%;两者均可抑制肝脏XOD活性(P<0.01或P<0.05),相同生药量毛蕊花糖苷对XOD的抑制等效率达车前子醇提物的66.1%~82.2%;两者均可下调肾脏尿酸mURAT1及m GLUT9 mRNA的表达(P<0.05或P<0.01),相同生药量毛蕊花糖苷对肾mURAT1及m GLUT9 mRNA表达下调等效率分别达车前子醇提物的57.7%~83.2%与56.0%~76.2%;且车前子醇提物可上调肾脏mOAT1 mRNA的表达(P<0.05或P<0.01),但毛蕊花糖苷则对肾脏mOAT1 mRNA不具备上调功能(P>0.05);另外,两者均可降低高尿酸血症小鼠血清CRE及BUN水平(P<0.05或P<0.01),相同生药量毛蕊花糖苷对高尿酸血症小鼠血清CRE及BUN清除等效率分别达车前子醇提物的80.0%~87.5%和59.9%~70.9%。结论毛蕊花糖苷为车前子降尿酸主要物质基础,具有与车前子醇提物相似但不完全相同的降尿酸机制,可做为车前子降尿酸药物开发及质量控制的主要依据。     

Wudang cherry ameliorates urate underexcretion and renal dysfunction in hyperuricemic mice

OBJECTIVE To investigate effects of Wudang cherry on urate excretion and renal function and examined whether renal organic ion transporters were involved in potassium oxonateinduced hyperuricemic mice.METHODS The model of hyperuricemic mice was induced by intraperitoneal injection of potassium oxonate(250 mg·kg~(-1))for 7 d.Water extracts of Wudang cherry at 500 mg·kg~(-1)were orally administered to hyperuricemic mice for 7 d,benzbromarone(20 mg·kg~(-1))and allopurinol(20 mg·kg~(-1))were given as positive controls,vehicle control group was given equal normal saline.Serum and urine levels of uric acid were measured in hyperuricemic and normal mice.Simultaneously,the m RNA and protein levels of mouse urate transporter 1(m URAT1),glucose transporter 9(mGLUT9),organic anion transporters(mOAT1 and mOAT3),ATP-binding cassette,subfamily G,membrane 2(mABCG2)and organic cation/carnitine transporters(m OCT1,m OCT2,m OCTN1 and m OCTN2)in the kidney were analyzed by Western blot,RT-PCR,immunohistochemical and immunofluorescent assay,respectively.RESULTS Wudang cherry significantly reduced serum uric acid levels and increased urine uric acid levels in hyperuricemic mice.And it effectively reversed potassium oxonate-induced alterations in renal m URAT1,mGLUT9,mOAT1,mOAT3 and mABCG2 m RNA and protein levels,resulting in the enhancement of renal urate excretion in mice.Moreover,Wudang Cherry increased renal m OCT1,m OCT2,m OCTN1 and m OCTN2 m RNA and protein levels,and improved renal impairment in this model.CONCLUSION Wudang cherry processes uricosuric and nephroprotective actions by regulating renal organic ion transporters in hyperuricemic mice.     

Mulberroside a possesses potent uricosuric and nephroprotective effects in hyperuricemic mice

Mulberroside A is a major stilbene glycoside of MORUS ALBA L. (Moraceae), which is effectively used for the treatment of hyperuricemia and gout in traditional Chinese medicine. We examined whether mulberroside A had effects on renal urate underexcretion and dysfunction in oxonate-induced hyperuricemic mice and investigated the potential uricosuric and nephroprotective mechanisms involved. Mulberroside A at 10, 20, and 40 mg/kg decreased serum uric acid levels and increased urinary urate excretion and fractional excretion of uric acid in hyperuricemic mice. Simultaneously, it reduced serum levels of creatinine and urea nitrogen (10-40 mg/kg), urinary N-acetyl- β-D-glucosaminidase activity (10-40 mg/kg), β?-microglobulin (10-40 mg/kg) and albumin (20-40 mg/kg), and increased creatinine clearance (10-40 mg/kg) in hyperuricemic mice. Furthermore, mulberroside A downregulated mRNA and protein levels of renal glucose transporter 9 (mGLUT9) and urate transporter 1 (mURAT1), and upregulated mRNA and protein levels of renal organic anion transporter 1 (mOAT1) and organic cation and carnitine transporters (mOCT1, mOCT2, mOCTN1, and mOCTN2) in hyperuricemic mice. This is the first study demonstrating that mulberroside A exhibits uricosuric and nephroprotective effects mediated in part by cooperative attenuation of the expression alterations of renal organic ion transporters in hyperuricemic mice. These data suggest that mulberroside A may be a new drug candidate for the treatment of hyperuricemia with renal dysfunction.     

慢性尿酸性肾病致肾功能损害52例治疗分析

目的 分析慢性尿酸性肾病致肾功能损害患者的临床治疗效果.方法 对52例慢性尿酸性肾病致肾功能损害患者,采用降尿酸方法,控制血尿酸至正常水平,定期观察肾功能及相关指标的变化,治疗1年后进行疗效统计分析.结果 52例接受治疗的患者,血尿酸（SUA）均显著降低（P ＜ 0.05）,血肌酐（SCr）、血尿素氮（BUN）、肾小球滤过率估算值（eGFR）等肾功能指数明显改善（P ＜ 0.05）,蛋白尿、血尿亦明显改善（P ＜ 0.05）.结论 降低血尿酸至合适水平,可有效控制慢性尿酸性肾病致肾功能损害的进展,改善肾功能.     

Effect of Eurycoma longifolia stem extract on uric acid excretion in hyperuricemia mice

OBJECTIVE Eurycoma longifolia is a tropical medicinal plant belonging to Simaroubaceae distributed in South East Asia. The aim of this study is to explore the effect and mechanism of E. longifolia stem 70% ethanol extract(EL) and its active compoundson uric acid excretion. METHODS Potassium oxonate(PO) induced hyperuricemia rats and adenine-PO induced hyperuricemia mouse model were used to evaluate the effects of EL. Ultra Performance Liquid Chromatography was used to determine the levels of plasma or serum uric acid and creatinine. Hematoxylin-eosin staining was applied to observe kidney pathological changes, Western blotting was applied to detect protein expression levels of uric acid transporters. Effects of constituents on urate uptake were tested in h URAT1-expressing HEK293 T cells. RESULTS EL significantly reduced serum and plasma uric acid levels at dosages of 100, 200 and400 mg·kg~(-1) in hyperuricemia rats and mice, and increased the clearance rate of uric acid and creatinine, improved therenal pathological injury. The protein expression levels of urate reabsorption transporter 1(URAT1) and glucose transporter 9 were down-regulated while sodium-dependent phosphate transporter 1 and ATP-binding cassette transporter G2 were up-regulated in the kidney after EL treatment. The diterpenes(50 μmol·L~(-1)) isolated from EL showed inhibitory effects on urate uptake in h URAT1-expressing HEK293 T cells,and the effect of eurycomanol was further confirmed in vivo. CONCLUSION EL significantly reduced blood uric acid levels and prevented pathological changes of kidney in PO induced hyperuricemia animal model, improved renal urate transports. We partly clarified the mechanism was related to suppressing effect of URAT1 by diterpene in EL. This study is the first to demonstrate that EL plays a role in hyperuricemia by promoting renal uric acid excretion.     

尿酸转运蛋白研究进展

体内尿酸经肾脏转运时需依赖肾小管上皮细胞上的转运蛋白。现已明确有4种尿酸盐转运蛋白参与了人近曲肾小管对尿酸盐的转运：即负责尿酸重吸收的尿酸盐阴离子转运体1（hURATl）,及负责尿酸分泌的尿酸盐转运体（UAT）和有机阴离子转运体（OATl和OAT3）。最近,又发现了一种负责将尿酸分泌到细胞外,参与肾脏近曲小管对尿酸盐的重吸收的转运蛋白一一葡萄糖转运蛋白9（GLUT9）。本文对尿酸转运蛋白的特点、功能及调节机制进行综述。     

Reducing effect of mangiferin on serum uric acid levels in mice

Context: Mangiferin, a natural bioactive xanthone C-glycoside, is widely present in medicinal plants like the leaf of Mangifera indica L. (Anacardiaceae). It has been reported that mangiferin possesses a variety of biological activities, including antidiabetic, hepatoprotective, anti-inflammatory, antioxidant, and anticarcinogenic. Objective: The hypouricemic effect and xanthine oxidoreductase (XOR) inhibitory activity of mangiferin were investigated here for the first time. Materials and methods: The hypouricemic effect of mangiferin was investigated in normal and hyperuricemic mice induced by potassium oxonate. Mangiferin at a dose of 0.75-100.0 mg/kg was given intragastrically to mice. The serum urate levels were determined using the phosphotungstic acid method. The hepatic activities of xanthine dehydrogenase (XDH) and xanthine oxidase (XOD) in hyperuricemic mice were assayed using commercially available kits. Results: The results showed that mangiferin at a dose of 1.5, 3.0, and 6.0 mg/kg significantly reduced the serum urate levels (148.7 ± 37.8, 142.2 ± 44.5, 121.7 ± 21.7 μmmol/L) in hyperuricemic mice, compared with untreated hyperuricemic mice (201.8 ± 71.2 μmmol/L). However, mangiferin did not decrease the serum urate levels in normal mice until mangiferin was up to 100 mg/kg. In addition, the hepatic activities of XDH in hyperuricemic mice were significantly decreased by mangiferin, while no changes of XOD were observed. Acute toxicity study in mice showed that mangiferin was very safe at a dose of up to 25 g/kg. Discussion and conclusion: These findings demonstrate that mangiferin has the potential to be developed as a new therapeutic agent for the treatment of hyperuricemia and gout.