桔梗皂苷D减轻大鼠肾缺血/再灌注损伤

Platycodon D attenuates renal ischemia-reperfusion injury in rats

目的探究桔梗皂苷D(PD)对大鼠肾缺血/再灌注损伤的保护作用。方法将大鼠分为假手术组、模型组,PD低、中和高剂量组(n=10)。模型组、低、中和高剂量组大鼠通过夹闭大鼠双侧肾蒂来建立缺血/再灌注损伤模型,假手术组大鼠进行相同的建模手术操作,但不夹闭肾蒂。建模前5 min对低、中和高剂量组大鼠分别腹腔注射12.5、25和50 mg/kg的PD。建模24 h后,检测大鼠的血清肌酐(Cr)和血尿素氮(BUN)水平,以及肾组织抗氧化标志物[超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和丙二醛(MDA)]水平。苏木精-伊红(HE)染色评价肾组织病变。免疫组织化学染色检测肾组织caspase-3的表达,通过caspase-3阳性的细胞数量来评估肾小管上皮细胞的凋亡指数。RT-qPCR检测肾组织炎性因子白细胞介素-1β(IL-1β)、IL-6和IL-10的mRNA表达。Western blot检测Toll样受体4(TLR4)、髓样分化因子88(MyD88)、p65、p-p65、核因子κB(NF-κB)抑制因子(IκB)和p-IκB的表达。结果与假手术组相比,模型组大鼠的肾脏病变程度、血清Cr和BUN水平、肾小管上皮细胞的凋亡指数均升高(P<0.05)。与模型组大鼠相比,低、中和高剂量组大鼠的肾脏病变程度、血清Cr和BUN水平、肾小管上皮细胞的凋亡指数均降低(P<0.05)。与假手术组相比,模型组大鼠的肾组织中MDA水平、IL-1β和IL-6的mRNA水平和TLR4/MyD88/NF-κB信号通路蛋白表达水平均升高,SOD和GSH-Px水平以及IL-10的mRNA水平均降低(P<0.05)。与模型组大鼠相比,低、中和高剂量组大鼠的肾组织中MDA水平、IL-1β和IL-6的mRNA水平和TLR4/MyD88/NF-κB信号通路蛋白表达水平均降低,SOD和GSH-Px水平以及IL-10的mRNA水平均升高(P<0.05)。结论桔梗皂苷D对大鼠肾缺血/再灌注损伤有保护作用,其机制可能与提高抗氧化能力和抑制TLR4/MyD88/NF-κB信号通路有关。

Objective To investigate the protective effect of Platycodin D(PD)on renal ischemia-reperfusion injury in rats.Methods The rats were divided into sham group,model group,low,middle and high-dose groups with 10 animals in each.The rat model of ischemia reperfusion injury was established by clamping the bilateral renal pedicles in model group,low,middle and high-dose group.The rats in sham group underwent the same modeling operation but did not clamp the renal pedicles.Before 5 minutes of modeling,the rats of low,middle and high-dose group were intra-peritoneally injected with 12.5,25 and 50 mg/kg PD,respectively.After 24 h of modeling,the serum creatinine(Cr)and blood urea nitrogen(BUN)levels,as well as antioxidant markers[superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and malondialdehyde(MDA)]levels in kidney tissues were measured.HE staining was used to evaluate renal tissue lesions.Immuno-histochemical staining was used to detect the expression of caspase-3 in renal tissue,the apoptosis index of renal tubular epithelial cells was evaluated by the counting of caspase-3 positive cells.RT-qPCR was used to detect the expression of interleukin-1β(IL-1β),IL-6 and IL-10 mRNA in renal tissues.Western blot was used to detect the expression of Toll-like receptor 4(TLR4),myeloid differentiation factor 88(MyD88),p65,p-p65,inhibitor of nuclear factor kappa B(NF-κB)(IκB)and p-IκB.Results Compared with sham group,the kidney lesions,serum Cr and BUN levels,apoptosis index of renal tubular epithelial cells in model group were all increased(P<0.05).Compared with model group,the kidney lesions,serum Cr and BUN levels,apoptosis index of renal tubular epithelial cells in low,middle and high-dose group were decreased(P<0.05).Compared with sham group,the level of MDA and mRNA of IL-1βand IL-6,the protein expression of TLR4/MyD88/NF-κB signaling pathway in kidney tissue in model group were all significantly increased while the level of SOD and GSH-Px and mRNA of IL-10 in rat kidney tissue were decreased(P<0.05).Compared with model group,the level of MDA,mRNA of IL-1βand IL-6,the protein expression of TLR4/MyD88/NF-κB signaling pathway in kidney tissue in low,middle and high-dose group were all decreased,SOD and GSH-Px and IL-10 mRNA in rat kidney tissue were increased(P<0.05).Conclusions Platycodin D has a protective effect on renal ischemia-reperfusion injury in rats,and the underlying mechanism may be related to the improvement of antioxidant capacity and inhibition of TLR4/MyD88/NF-κB signaling pathway.