芒果苷促进高尿酸血症小鼠尿酸排泄和肾功能改善以及调节相关肾脏转运体的作用
Mangiferin promotes uric acid excretion and kidney function improvement and modulates related renal transporters in hyperuricemic mice
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摘要:
在氧嗪酸钾盐诱导小鼠产生高尿酸血症模型上, 研究芒果苷促进尿酸排泄和肾功能改善以及调节相关肾脏转运体的作用。实验动物随机分为正常对照组、高尿酸血症模型对照组、芒果苷50、100和200 mg·kg−1剂量组、别嘌醇5 mg·kg−1剂量组。每天在灌胃给予氧嗪酸钾盐 (250 mg·kg−1) 1 h后灌胃给药, 连续7天。分别测定血清尿酸、肌酐与尿素氮水平及尿液尿酸和肌酐水平。采用RT-PCR和Western blotting方法分别测定动物肾脏转运体mRNA及蛋白表达水平。采用ELISA方法检测血清、尿液和肾脏尿调素 (UMOD) 含量。与模型对照组比较, 芒果苷显著降低高尿酸血症小鼠血清尿酸、肌酐和尿素氮水平, 提高24 h尿液尿酸和肌酐排泄量以及尿酸排泄分数, 具有促进肾脏尿酸排泄和保护肾功能作用。研究发现, 芒果苷显著下调高尿酸血症小鼠肾脏尿酸盐重吸收转运体1 (mURAT1) 和葡萄糖转运体9 (mGLUT9) mRNA和蛋白表达并上调肾脏有机阴离子转运体1 (mOAT1) 表达, 提示芒果苷可能通过抑制肾脏尿酸重吸收和增加尿酸分泌而促进高尿酸血症小鼠尿酸排泄以降低血清尿酸水平。另外, 芒果苷显著上调肾脏有机阳离子和肉毒碱转运体 (mOCT1、mOCT2、mOCTN1和mOCTN2) 表达水平、提高尿液mUMOD水平并降低血清和肾脏mUMOD水平, 这些发现可能与其改善肾功能作用有关。
Abstract:The effects of mangiferin on uric acid excretion, kidney function and related renal transporters were investigated in hyperuricemic mice induced by potassium oxonate. Mice were divided into normal control group, and 5 hyperuricemic groups with model control, 50, 100, and 200 mg·kg−1 mangiferin, and 5 mg·kg−1 allopurinol. Mice were administered by gavage once daily with 250 mg·kg−1 potassium oxonate for seven consecutive days to create the model. And 3 doses of mangiferin were orally initiated on the day 1 h after potassium oxonate was given, separately. Serum uric acid, creatinine and urea nitrogon levels, as well as urinary uric acid creatinine levels were measured. Mouse uromodulin (mUMOD) levels in serum, urine and kidney were determined by ELISA method. The mRNA and protein levels of related renal transporters were assayed by RT-PCR and Western blotting methods, respectively. Compared to model group, mangiferin significantly reduced serum uric acid, creatinine and urea nitrogon levels, increased 24 h uric acid and creatinine excretion, and fractional excretion of uric acid in hyperuricemic mice, exhibiting uric acid excretion enhancement and kidney function improvement. Mangiferin was found to down-regulate mRNA and protein levels of urate transporter 1 (mURAT1) and glucose transporter 9 (mGLUT9), as well as up-regulate organic anion transporter 1 (mOAT1) in the kidney of hyperuricemic mice. These findings suggested that mangiferin might enhance uric acid excretion and in turn reduce serum uric acid level through the decrease of uric acid reabsorption and the increase of uric acid secretion in hyperuricemic mice. Moreover, mangiferin remarkably up-regulated expression levels of renal organic cation and carnitine transporters (mOCT1, mOCT2, mOCTN1 and mOCTN2), increased urine mUMOD levels, as well as decreased serum and kidney mUMOD levels in hyperuricemic mice, which might be involved in mangiferin-mediated renal protective action.
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