单宁酸对糖尿病模型大鼠肾脏氧化应激水平及炎性因子表达的抑制作用

目的 观察单宁酸对糖尿病模型大鼠抗氧化能力的影响及对机体微炎症状态的改善作用.方法 选择6周龄健康雄性Wistar大鼠68只,随机选取其中8只作为正常对照组,其余60只给予高糖高脂饲料喂养4周后以链脲佐菌素（STZ）按52 mg/kg单次腹腔注射制造糖尿病大鼠模型,造模成功的大鼠进一步随机分为模型组、氨基胍组、单宁酸低剂量组、单宁酸高剂量组,各15只.氨基胍组及单宁酸低、高剂量组分别腹腔注射氨基胍40 mg/（kg·d）及单宁酸[20、30 mg/（kg·d）],正常对照组和模型组给予0.9％氯化钠注射液[30 mg/（kg·d）],10周后处死大鼠取材.化学比色法检测各组大鼠血清及肾皮质丙二醛含量及谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性;酶联免疫吸附测定法检测肾组织匀浆8-羟基脱氧鸟苷（8-OHdG）含量、血清C反应蛋白（CRP）水平;免疫组织化学检测肾组织细胞间黏附分子1（ICAM-1）、单核细胞趋化蛋白1（MCP-1）的蛋白表达,逆转录-聚合酶链反应检测肾组织ICAM-1、MCP-1 mRNA表达.结果 单宁酸低、高剂量组大鼠血清丙二醛含量明显低于模型组[（23.5±8.5）、（19.8±5.3） μmol/L比（35.5±14.6） μmol/L]（P＜0.05或P＜0.01）,GSH-Px、总SOD及CAT活性明显高于模型组[GSH-Px：（295 ±58）、（322±52） U/L比（232 ±72） U/L,总SOD：（75±13）、（86±15） U/ml比（49±13） U/ml,CAT：（6.9±2.2）、（7.2±2.9） U/ml比（3.7±1.4） U/ml]（P＜0.05或P＜0.01）;单宁酸低、高剂量组大鼠肾组织匀浆丙二醛含量明显低于模型组[（344±120）、（269±52） μmol/L比（464±62） μmol/L]（P＜0.05或P＜0.01）;单宁酸高剂量组GSH-Px活性明显高于模型组[（32 ±8）U/L比（17±4） U/L]（P＜0.01）;单宁酸低剂量组总SOD活性明显高于模型组[（23±4）U/ml比（17±4） U/ml] （P＜0.05）;单宁酸高剂量组大鼠肾组织8-O

Ameliorating effect of tannic acid on oxidative stress and micro-inflammatory state in diabetic rats

Objective To investigate the ameliorating effect of tannic acid （TA） on antioxidant capacity and micro-inflammatory state in diabetic rats.Methods Totally 8 out of 68 6-week-old male Wistar rats were as a control group ; the remaining 60 rats had high-sugar and high-fat diet for 4 weeks and were injected streptozotocin （STZ,52 mg/kg） intraperitoneally in order to manufacture a diabetic rat model.The diabetic rats were randomly divided into model group,aminoguanidine group,low-dose of tannic acid group and high dose of tannic acid group.The rats in aminoguanidine group were injected aminoguanidine [AG,40 mg/（kg · d）] intraperitoneally;those in low-dose of tannic acid group were injected tannic acid [TA,20 mg/（kg · d）] and those in high-dose of tannic acid group were injected tannic acid [TA,30 mg/（kg · d）].The rats in normal control group and model group were injected normal saline （NS,30 mg/（kg · d）.All rats were sacrificed and tissues were derived at the end of week 10.The content of malondialdehyde （MDA） and the activities of glutathione peroxidase （GSH-Px）,superoxide dismutase （SOD） and catalase （CAT） in serum and renal tissue were measured.8-hydroxy-2-deoxyguanosine （8-OHdG） in homogenates of renal tissue and the level of C-reactive protein （CRP） in plasma were detected by ELISA method.The expressions of protein and mRNA of ICAM-1 and MCP-1 in renal tissue were determined by immunohistochemical stain and RT-PCR method.Results The contents of MDA in serum in lowdose of tannic acid group and high-dose of tannic acid group were significantly lower than those in model group [（23.5 ± 8.5）,（19.8 ± 5.3） μmol/L vs （35.5 ± 14.6） μmol/L] （P 〈 0.05 or P 〈 0.01） and the activity of GSH-Px,total-SOD and CAT in low-dose and high dose of tannic acid group were significantly higher than those in model group [GSH-Px：（295 ± 58）,（322 ± 52） U/L vs （232 ± 72） U/L,total-SOD：（75 ± 13）,（86 ± 15） U/ml vs （49±13）U/ml,CAT：