圣草酚对脓毒症致大鼠急性肾损伤的保护作用及机制研究

Study on the Protective Effect and Mechanism of Eriodictyol on Acute Renal Injury Induced by Sepsis in Rats

目的:探讨圣草酚对脓毒症急性肾损伤(SAKI)大鼠的影响,并阐明其作用机制。方法:采用盲肠结扎穿孔术建立脓毒症大鼠模型,将造模成功的大鼠随机分成模型组、圣草酚低剂量组、圣草酚高剂量组和圣草酚高剂量+核因子E2相关因子2(Nrf2)抑制剂组,另设置假手术组,每组10只。于造模前2 d开始给予圣草酚和Nrf2抑制剂预处理,持续干预3 d。术后24 h,生化法检测血清肌酐(Scr)、血尿素氮(BUN)水平;ELISA检测血清中IL-1β、IL-6浓度及肾组织中丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性水平;HE染色观察肾组织病理学变化;荧光探针染色法检测大鼠肾组织活性氧(ROS)水平;Western blot检测大鼠肾脏组织中Nrf2和血红素加氧酶1(HO-1)蛋白表达水平。结果:与假手术组比较,模型组大鼠血清中Scr、BUN、IL-1β和IL-6水平显著升高(P<0.05),肾组织损伤严重,肾小管损伤评分显著升高(P<0.05),肾组织中ROS水平升高,SOD活性及Nrf2和HO-1蛋白表达水平显著降低(P<0.05)。与模型组比较,圣草酚高剂量组血清中Scr、BUN、IL-1β和IL-6水平显著降低(P<0.05),肾组织损伤减轻,肾小管损伤评分显著降低(P<0.05),肾组织中ROS水平降低,SOD活性及Nrf2和HO-1蛋白表达水平显著升高(P<0.05),而圣草酚低剂量组各指标差异无统计学意义(P>0.05)。Nrf2抑制剂逆转了高剂量圣草酚对SAKI大鼠氧化应激和炎症反应的抑制作用(P<0.05)。结论:圣草酚预处理可抑制SAKI大鼠氧化应激和炎症水平,减轻肾脏损伤,其作用机制与激活Nrf2/HO-1信号通路有关。

Objective:Explore the effect of Eriodictyol on acute kidney injury(SAKI)in rats with sepsis and elucidate its mechanism of action.Methods:A sepsis rat model was established using cecal ligation and perforation surgery.The successfully modeled rats were randomly divided into model group,low-dose Eriodictyol group,high-dose Eriodictyol group,and high-dose Eriodictyol+nuclear factor E2-related factor 2(Nrf2)inhibitor group,and sham surgery group was also established,10 rats in each group.Pre treatment with Eriodictyo and Nrf2 inhibitor was started 2 days before modeling,and continuous intervention for 3 days.24 hours after surgery,serum creatinine(Scr)and blood urea nitrogen(BUN)levels were measured using biochemical methods.The concentration of IL-1βand IL-6 in serum and levels of malondialdehyde(MDA)and superoxide dismutase(SOD)in renal tissue were detected by ELISA.The change of renal histopathology was observed by HE staining.The reactive oxygen species(ROS)level in rat kidney tissue was detected by fluorescence probe staining.The protein expression levels of Nrf2 and Heme-oxygenase 1(HO-1)in rat kidney tissue were detected by Western blot.Results:Compared with the sham surgery group,the levels of Scr,Bun,IL-1βand IL-6 in serum of the model group rats were significantly increased(P<0.05),renal tissue injury was severe,renal tubular injury score was significantly increased(P<0.05),ROS levels in renal tissue were increased,SOD activity and Nrf2 and HO-1 protein expression levels were significantly reduced(P<0.05).Compared with the model group,there was no significant difference in all indicators in the low-dose group of Eriodictyo(P>0.05).The levels of Scr,Bun,IL-1βand IL-6 in serum of the high-dose group of Eriodictyo were significantly reduced(P<0.05),renal tissue damage was alleviated,renal tubular injury score was significantly reduced(P<0.05),ROS levels in renal tissue were reduced,SOD activity and Nrf2 and HO-1 protein expression levels were significantly increased(P<0.05).Nrf2 inhibitor reversed the inhibitory effect of high-dose Eriodictyo on oxidative stress and inflammatory response in SAKI rats(P<0.05).Conclusion:Eriodictyo pretreatment can inhibit oxidative stress and inflammation levels in sepsis acute kidney injury rats,alleviate kidney damage,and its mechanism of action is related to the activation of Nrf2/HO-1 signaling pathway.