三七皂苷对急性肾损伤大鼠的保护作用及机制

Protective effect and mechanism of Panax notoginseng saponins on acute kidney injury in rats

目的 探讨三七皂苷对急性肾损伤大鼠的保护作用及分子机制.方法 30只SD大鼠随机分为对照组、模型组和三七皂苷组,每组10只.模型组和三七皂苷组大鼠采用一次性灌胃给予2 g/kg对乙酰氨基酚建立急性肾损伤模型,建模成功后24 h,三七皂苷组大鼠经腹腔注射三七皂苷100 mg/kg,对照组和模型组经腹腔注射等体积生理盐水.治疗10 d后分析3组大鼠肾指数;采用苏木精-伊红(HE)染色观察3组大鼠肾病理变化;采用试剂盒检测3组大鼠血清肌酐和血尿氮水平;采用生物化学法分析3组大鼠血清氧化应激指标丙二醛(MDA)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)水平;采用酶联免疫吸附试验(ELISA)检测3组大鼠血清炎性因子[白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)]水平;采用蛋白质印迹法(Western blot)检测3组大鼠肾组织磷酸化p38丝裂原活化蛋白激酶(p-p38 MAPK)、磷酸化细胞外信号调节激酶(p-ERK)和磷酸化c-Jun氨基末端激酶(p-JNK)蛋白表达水平;组间计量数据比较采用单因素方差分析.结果 三七皂苷组大鼠肾指数(0.95±0.04)明显低于模型组大鼠肾指数(1.13±0.07),差异有统计学意义(t=7.547,P<0.05).三七皂苷组大鼠血清肌酐和血尿氮[(47.31±4.40)μmol/L和(18.65±1.88)mmol/L]明显低于模型组[(76.52±5.34)μmol/L 和(26.31±2.74)mmol/L],差异有统计学意义(t=13.350、7.288,P<0.05).三七皂苷组大鼠肾脏病理评分[(1.60±0.70)分]明显低于模型组[(3.80±0.63)分],差异有统计学意义(t=7.379,P<0.05).三七皂苷组大鼠肾脏组织SOD活性和 GSH-Px 水平[(217.37±13.29)U/mg 和(1.60±0.09)μmol/L]明显高于模型组[(142.33±18.88)U/mg 和(1.18±0.11)μmol/L],差异有统计学意义(t=10.280、9.457,P<0.05).三七皂苷组大鼠肾脏MDA水平[(0.80±0.07)nmol/mg]明显低于模型组[(1.44±0.14)nmol/mg],差异有统计学意义(t=12.830,P<0.05).三七皂苷组大鼠血清TNF-α和IL-6水平[(67.96±9.84)pg/ml和(91.92±6.63)pg/ml]明显低于模型组[(67.96±9.84)pg/ml 和(91.92±6.63)pg/ml],差异有统计学意义(t=9.384、14.020,P<0.05).三七皂苷组大鼠肾脏组织p-p38 MAPK、p-ERK和p-JNK蛋白表达水平(1.21±0.08、1.16±0.14、1.32±0.13)明显低于模型组(1.74±0.14、1.55±0.16、1.94±0.09),差异有统计学意义(t=10.280、5.887、12.460,P<0.05).结论 三七皂苷通过抑制MAPK信号通路表达,从而减轻炎性因子释放,改善肾损伤,起到保护肾功能作用.

Objective To explore the protective effect and molecular mechanism of Panax notogin-seng saponins on acute kidney injury in rats.Methods Totally,30 SD rats were randomly divided into a control group,a model group,and a notoginseng saponin group,with 10 rats in each group.The rats in the model group and notoginseng saponin group were given a one-time gavage of 2 g/kg acetaminophen to estab-lish acute kidney injury models.At 24 h after successful modeling,the rats in the notoginseng saponin group were intraperitoneally injected with 100 mg/kg notoginseng saponin,and those in the control group and model group were intraperitoneally injected with equal volume of physiological saline.The renal index of three groups after 10 days of treatment was analyzed.The pathological changes in the kidneys of three groups were analyzed by hematoxylin eosin(HE)staining.The serum creatinine and urine nitrogen levels were determined using a reagent kit.The levels of serum oxidative stress indicators such as malondialde-hyde(MDA),superoxide dismutase(SOD),and glutathione peroxidase(GSH-Px)in three groups were measured by Biochemical methods.The levels of serum inflammatory factors[interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)]in three groups were detected by enzyme linked immunosorbent assay(ELISA).The expression levels of phosphorylated p38 mitogen-activated protein kinase(p-p38 MAPK),phosphorylated extracellular signal-regulated kinase(p-ERK),and phosphorylated c-Jun N-terminal kinase(p-JNK)proteins in the renal tissues of three groups were detected by Western blotting.The comparison of inter group econometric data was conducted using one-way analysis of variance.Results The renal index of the rats in the Panax notoginseng saponin group(0.95±0.04)was significantly lower than that in the model group(1.13±0.07,t=7.547,P<0.05).Serum creatinine and urine nitrogen in rats treated with Panax notoginseng saponins[(47.31±4.40)and(18.65±1.88)mmol/L]were significantly lower than those in the model group[(76.52±5.34)and(26.31±2.74)mmol/L,t=13.350,7.288,P<0.05].The renal pathological score in the Panax notoginseng saponin group(1.60±0.70)was significantly lower than that in the model group(3.80±0.63,t=7.379,P<0.05).SOD activity and GSH-Px levels in kid-ney tissue of rats treated with Panax notoginseng saponins[(217.37±13.29)and(1.60±0.09)μmol/L]were significantly higher than in the model group[(142.33±18.88)and(1.18±0.11)μmol/L,t=10.280,9.457,P<0.05].The renal MDA levels in the Panax notoginseng saponin group[(0.80±0.07)nmol/mg]were significantly lower than those in the model group[(1.44±0.14)nmol/mg,t=12.830,P<0.05].The serum levels of TNF-αand IL-6 in the Panax notoginseng saponin group[(67.96±9.84)and(91.92±6.63)pg/ml]were significantly lower than those in the model group[(67.96±9.84)and(91.92±6.63)pg/ml,t=9.384,14.020,P<0.05].The expression levels of p-p38 MAPK,p-ERK,and p-JNK proteins in the kidney tissue of rats in the Panax notoginseng saponin group[(1.21±0.08,1.16±0.14,1.32±0.13)were significantly lower than those in the model group(1.74±0.14,1.55±0.16,1.94±0.09,t=10.280,5.887,12.460,P<0.05).Conclusion Panax notoginseng saponins can reduce the release of inflammatory factors,improve renal injury,and protect renal function by inhibiting the expression of MAPK signaling pathway.