荞麦花叶发酵提取物对2型糖尿病db/db小鼠肾损伤的影响

Influence of extract from fermented buckwheat flower and leaf in kidney injury in type 2 diabetic db/db mice

目的:探讨荞麦花叶发酵提取物(EFBFL)对自发肥胖2型糖尿病db/db小鼠肾脏损伤的保护作用,从肾脏过氧化物酶体增殖物激活受体γ(PPARγ)和核因子κB(NF-κB)的蛋白表达水平阐明其可能的机制。方法:选择8周龄雄性db/db小鼠,以同窝db/m小鼠为正常对照组,db/db小鼠随机分为模型组、低剂量EFBFL组和高剂量EFBFL组,每组10只。低和高剂量EFBFL组小鼠分别为给予50和100mg·kg-1 EFBFL灌胃,正常对照组和模型组小鼠给予等量蒸馏水灌胃,每天1次,连续8周。于给药前后检测各组小鼠空腹血糖(FBG),全自动生化分析仪检测血清中血肌酐(SCr)和尿素氮(BUN)水平,计算肾脏指数,通过HE和Masson染色观察小鼠肾组织形态表现,免疫组织化学法和Western blotting法检测小鼠肾组织PPARγ和NF-κB蛋白表达水平。结果:与模型组比较,EFBFL组小鼠FBG及血清中SCr、BUN水平明显降低(P<0.05或P<0.01),肾脏指数增加(P<0.01)。与正常对照组比较,模型组小鼠肾组织中肾小球萎缩,肾小球基底膜弥漫性增厚,足突融合甚至消失,肾组织纤维化程度严重;与模型组比较,EFBFL组小鼠上述表现不同程度改善,以高剂量EFBFL组尤为明显。与模型组比较,EFBFL组小鼠肾组织PPARγ蛋白表达水平升高(P<0.05或P<0.01),NF-κB蛋白表达水平降低(P<0.05或P<0.01)。结论:EFBFL可改善自发肥胖2型糖尿病db/db小鼠肾损伤,其机制可能与降低小鼠血糖、促进肾PPARγ蛋白的表达及下调NF-κB的蛋白表达有关。

Objective:To discuss the protective effects of extract from fermented buckwheat flower and leaf(EFBFL)on the kidney injury in the spontaneously obese type Ⅱ diabetic db/db mice,and to elucidate their possible action mechanisms from the protein expression levels of peroxisome proliferator-activated receptorγ(PPARγ)and nuclear factor-κB(NF-κB)in kidney tissue.Methods:The 8 weeks old male db/db mice were selected and the littermate db/m mice were used as normal control group;the db/db mice were randomly divided into model group,low dose of EFBFL group and high dose of EFBFL group,10 mice in each group.The mice in low and high doses of EFBFL groups were intragastrically given 50 and 100 mg·kg-1 EFBFL,and the mice in normal control group and model group were intragastrically given the equal amount of distilled water once daily for8 weeks accordingly.The levels of fasting blood-glucose(FBG)of the mice in various groups were tested respectively before and after administration.Full automatic biochemical analyzer was used to detect the levels of serum creatinine(SCr)and blood urea nitrogen(BUN)of the mice,and the kidney index was calculated.The morphology of kidney tissue was observed by HE staining and Masson staining,and immunohistochemical method and Western blotting method were used to detect the expression levels of PPARγand NF-κB protein in kidney tissue.Results:Compared with model group,the levels of FBG and the levels of serum SCr and BUN in EFBFL groups were significantly decreased(P<0.05 or P<0.01),and the kidney indexes were increased(P<0.01).Compared with normal control group,the kidney glomerular of the mice in model group was weaked,glomerular basement membrane was diffusely thickened,the foot process was coalesced or disappeared,and the kidney tissue fibrosis was serious;compared with the model group,the above performance of the mice in EFBFL groups were improved in different degrees,especially in high dose of EFBFL group.Compared with model group,the expression levels of PPARγin kidney tissue of the mice in EFBFL groups were increased(P<0.01)and the expression levels of NF-κB in kidney tissue of the mice were decreased(P <0.01).Conclusion:EFBFL can improve the kidney injury in the spontaneously obese typeⅡ diabetic db/db mice,and its possible mechanism may be related to lowering the level of blood glucose,up-regulating the expression of PPARγand down-regulating the expression of NF-κB in the kidney tissue of the mice.