松果菊苷对链脲佐菌素所致糖尿病肾病模型大鼠肾脏的保护作用

The protective effect of echinoside on the kidney of diabetic nephropathy rats induced by streptozotocin

目的研究松果菊苷对DN模型大鼠肾组织中诱导型一氧化氮合酶(inducible nitric oxide synthase, iNOS)和TGF-β1表达的影响。方法将60只雄性SPF级SD大鼠按随机数字法分为正常组、模型组、格列本脲组和松果菊苷低、中、高剂量组,每组10只。除正常组外,其余各组大鼠一次性腹腔注射STZ诱导并建立DN模型。格列本脲组灌胃格列本脲片混悬液5 mg/(kg·d);松果菊苷低、中、高剂量组分别灌胃松果菊苷混悬液50、100、200 mg/(kg·d);正常组和模型组灌胃等体积生理盐水,1次/d。连续给药4周后,计算各组大鼠体重变化率、肾脏重量/体重;检测血糖、血清TC、TG、BUN、SCr水平及24 h尿蛋白定量;测定肾组织细胞培养液中NO释放浓度;采用HE染色观察各组大鼠肾组织病理学改变,Western blot法检测肾组织iNOS和TGF-β1蛋白表达。结果与模型组比较,中剂量组大鼠体重升高(P<0.05);中、高剂量组大鼠体重变化率及肾脏重量/体重降低(P<0.05),NO释放浓度降低(P<0.05);低、中、高剂量组大鼠血糖、TG、TC、BUN、SCr和24 h尿蛋白定量明显降低(P<0.05),肾组织iNOS[(1.35±0.06)、(1.15±0.05)、(0.91±0.04)比(4.58±0.09)]、TGF-β1[(1.24±0.04)、(1.41±0.05)、(0.89±0.04)比(3.04±0.05)]蛋白表达水平下调(P<0.05)。结论松果菊苷可降低STZ诱导的DN模型大鼠体重及血糖、TG、TC、BUN、SCr等指标水平,抑制肾脏组织中NO生成,下调肾脏组织iNOS、TGF-β1表达,对DN模型大鼠肾脏有一定的保护作用。

Objective To investigate the influence of echinoside on the expressions of inducible nitric oxide synthase (iNOS) and transforming growth factor-β1 (TGF-β1) in renal tissues of diabetic nephropathy rats. Methods A total of 60 male SD rats were randomly divided into the normal group, model group, glibenclamide group and low-, medium-, high-dose echinoside treatment group. the rat model of diabetic nephropathy was established through the streptozocin induction and the glibenclamide treatment was applied as control. After molding, glibenclamide group was given 5 mg/(kg?d) of glibenclamide, and low-, medium-, high-dose echinoside treatment group was given 50, 100 and 200 mg/(kg?d) of echinacoside solution. The normal group and model group were intragastrically given equal volume of normal saline. After 4 weeks, the change rate of body weight, kidney weight/body weight, blood glucose, serum TC, TG, BUN, SCR and 24 h urinary protein levels were measured, and the NO release concentration in renal tissue cell culture medium was measured, the renal pathology was observed by HE staining, the expression of iNOS and TGF-β1 proteins in renal tissues was detected by Western blotting. Results Compared with the model group, the body weight of rats in the medium-dose group significantly increased (P<0.05);the weight change rate and kidney weight/body weight of rat in the medium-, high-dose group significantly decreased (P<0.05), and the NO release concentration in the medium-, high-dose group decreased (P<0.05);the level of blood glucose, TC, TG, BUN, SCr, and 24-hour urinary protein in the low-, medium- and high-dose groups significantly decreased (P<0.05), and iNOS in renal tissue of rats in the low-, medium- and high-dose groups was significantly lower (P<0.05). Compared with the model group, the relative expression levels of TGF-β1 (1.35 ± 0.06, 1.15 ± 0.05, 0.91 ± 0.04 vs. 4.58 ± 0.09) and TGF-β1 (1.24 ± 0.04, 1.41 ± 0.05, 0.89 ± 0.04 vs. 3.04 ± 0.05) in the low-, medium- and high-dose groups significantly decreased (P<0.05). Conclusions The echinoside can prevent weight loss, reduce blood glucose and triglyceride, inhibit the production of NO in renal tissues, reduce the expression of iNOS and TGF-β1 among diabetic nephropathy rats. It has been proved to play a protective role in diabetic nephropathy pathological tissues.