夏枯草对STZ诱导的小鼠糖尿病视网膜病的改善作用

The Amelioration of Prunella Vulgaris L. on Diabetic Retinopathy Induced by STZ in Mice

目的:考察夏枯草水提物(PV)对链脲霉素(STZ)诱导的C57小鼠非增殖性糖尿病视网膜病(NPDR)的改善作用及其作用机制。方法:通过连续5 d腹腔注射STZ制备C57小鼠糖尿病模型,进而诱导建立糖尿病并发症NPDR实验动物模型。将造模成功的小鼠按体质量随机分为模型组、PV低剂量组(100 mg/kg)、PV高剂量组(200 mg/kg),另设有一组小鼠腹腔注射溶媒对照作为正常对照组,每组16只。小鼠末次腹腔注射STZ后1个月灌胃给药PV或生理盐水,连续1个月。采用视网膜组织伊文氏蓝渗漏实验检测NPDR小鼠中血-视网膜屏障(BRB)的破坏情况;采用ELISA方法检测血清中白介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的含量;采用Western-blot方法检测视网膜组织中小胶质细胞/巨噬细胞特异性蛋白(Iba1)的表达,并检测核因子κB(NF-κB)的转录激活。结果:模型组小鼠视网膜中伊文氏蓝渗漏值明显升高(P<0.001),而PV高低剂量组均对此有显著的改善作用(P<0.001);模型组小鼠血清中IL-1β、TNF-α含量明显高于正常组(P<0.05),而PV高低剂量组血清中IL-1β、TNF-α含量均较模型组明显降低(P<0.05,P<0.01,P<0.001)。模型组小鼠视网膜组织中Iba-1蛋白表达明显上调(P<0.001),而PV高低剂量组Iba-1表达明显低于模型组(P<0.001)。模型组小鼠视网膜组织中Phospho-p65蛋白含量显著增加(P<0.001),胞核中p65蛋白的表达显著上调(P<0.001);而PV高低剂量组中磷酸化p65蛋白表达明显低于模型组(P<0.05,P<0.001),胞核中p65蛋白表达明显低于模型组(P<0.001)。结论:PV能改善STZ诱导C57小鼠NPDR,其机制可能是抑制了NF-κB介导的炎性信号通路,减少了炎性因子IL-1β、TNF-α的表达,缓解了STZ诱导糖尿病小鼠视网膜组织的炎性损伤和BRB的渗漏。

Objective： To investigate the amelioration and mechanism of the aqueous extract from Prunella vulgaris L. （PV） on non-proliferative diabetic retinopathy （NPDR） induced by streptozotocin （STZ） in C57 mice. Methods： Model of mellitus diabetes （DM） in C.57 mice was established by intraperitoneal injection of STZ for continuous 5 days, and then NPDR model as diabetic complication was induced. According to body weight, successful modeling mice were randomly divided into the model group, PV group with low dose （100 mg/ kg）, PV group with high dose （200 mg / kg）, as well as the normal control group treated with intraperitoneal injection of solvent , 16 in each group. One month after the last intraperitoneal injection of STZ, the mice were administered orally with PV or normal saline for continuous 1 month. The breakdown of retinal blood-retinal barrier （BRB） in NPDR mice was evaluated by Evans blue leakage assay. Serum contents of interleukin （IL）-1 β and tumor necrosis factor （TNF） -α were detected by enzyme-linked immunosarbent assay （ELISA）. Expression of ionized calcium binding adapter molecule 1 （ Ibal ） in small glial cells / macrephage of retinal tissue and transcription and activation of nuclear faetor-KB （NF-KB） were detected by Western-blot. Results： The value of evans blue leakage in the retina of the model mice was significantly increased （ P 〈 0. 001 ）, and that in the groups treated with PV at different doses was significantly improved （P 〈 0.001 ） ; the contents of serum IL-1β, TNF-α in the model group mice were significantly higher than those of the normal group （ P 〈 0.05 ）, and those in the PV groups with high- and low- dose were both decreased significantly compared with the model group （ P 〈 0.05, P 〈 0.01, P 〈 0. 001 ）. In the model group, the expression of Iba- 1 protein in retinal tissue was significantly up-regulated （ P 〈 0. 001 ） , while the expression of Iba- 1 in the PV groups with high- and low-dose were significantly lower than that in the model group （ P 〈 0. 001 ）. Compared with the normal group, the phospho-p65 protein content of retinal tissue in the model group mice significantly increased （ P 〈 0. 001 ） , and the expression of p65 protein in nucleus up-regulated significantly （ P 〈 0. 001 ）. In the PV groups with high- and low-dose, the expression of phosphorylation p65 protein was significantly lower than that in the model group （ P 〈 0.05, P 〈 0. （301） , the expression of p65 protein in nucleus was significantly lower than that in the model group （ P 〈 0. 001 ）. Conclusion： PV could improve NPDR in STZ induced C57 mice, and the mechanism may inhibit the inflammatory signal pathway mediated by NF-KB, reduce the expression of inflammatory factors IL- 1 β and TNF-α, and thus alleviate the inflammatory damage and BRB leakage in retinal tissue of diabetic mice induced by STZ.