黄芪改善他克莫司慢性肾毒性的活性成分筛选及其作用机制研究

Screening of Effective Ingredients in Astragalus against Tacrolimus-induced Nephrotoxicity and Exploration of Underlying Mechanisms

目的:筛选黄芪改善他克莫司慢性肾毒性的活性组分,并初步阐明其作用机制。方法:将48只C57BL/6小鼠随机分为6组:空白对照组、模型组、黄芪总提取物组、黄芪总黄酮组、黄芪多糖组和黄芪总皂苷组,每组8只。除空白对照组外,其余各组采用他克莫司诱导慢性肾毒性模型,各治疗组同时灌胃给予相应的治疗药物,qd,连续28 d。末次给药后,检测各组小鼠尿量、体质量、血肌酐(SCr)、尿素氮(BUN);HE和Masson染色观察肾组织病理改变,Western blot检测肾组织转化生长因子β1(TGF-β1)、Ⅰ型胶原蛋白(CollagenⅠ)和α-平滑肌肌动蛋白(α-SMA)的表达,应用试剂盒测定超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)和丙二醛(MDA)水平。结果:与模型组相比,黄芪总提取物组、黄芪多糖和黄芪总皂苷可显著降低小鼠SCr、BUN、肾小管间质纤维化程度、TGF-β1、CollagenⅠ和α-SMA的蛋白表达(P<0.05或P<0.01),增加抗氧化酶SOD、CAT和GSH-Px的活性(P<0.05或P<0.01),显著降低MDA水平(P<0.05或P<0.01),而黄芪总黄酮无明显作用(P>0.05)。结论:黄芪多糖和黄芪总皂苷可能是黄芪发挥肾毒性保护作用的活性组分,其作用机制可能与减少氧化应激相关。

Objective:To screen the active components in Astragalus against tacrolimus-induced chronic nephrotoxicity and to clarify its mechanism of action.Methods:Totally 48 mice were randomly divided into 6 groups:blank control group,model group,total extract of Astragalu group,total flavonoids of Astragalus group,Astragalus polysaccharide group and total saponins of Astragalus group with 8 mice in each group.Except the blank control group,the other groups were used to induce chronic nephrotoxicity model by tacrolimus,and each treatment group was given corresponding treatment drug intragastrically,once a day for 28 consecutive days.After the last administration,the urine volume,body weight,blood creatinine and blood urea nitrogen were determined;HE and Masson staining were used to observe the pathological changes of renal tissue;Western blot was applied to determine the expressions of TGF-β1,CollagenⅠandα-SMA in renal tissue;the levels of SOD,CAT,GSH-Px and MDA were measured with kits.Results:Compared with the model group,total extract of Astragalus,Astragalus polysaccharides and total saponins of Astragalus remarkably reduced the blood creatinine,blood urea nitrogen,tubulointerstitial fibrosis,expressions of TGF-β1,CollagenⅠandα-SMA(P<0.05 or P<0.01),increased the activity of antioxidant enzymes SOD,CAT and GSH-Px(P<0.05 or P<0.01),and decreased the level of MDA(P<0.05 or P<0.01),while total flavonoids of Astragalus had no significant effect.Conclusion:Astragalus polysaccharides and total saponins of Astragalus are the active components in Astragalus for protecting from tacrolimus-induced chronic nephrotoxicity,and its mechanism may be related to the inhibition of oxidative stress.