目的 观察鼓槌石斛乙醇提取物(ethanol extract of Dendrobium chrysotoxum,EEDC)对链脲佐菌素(STZ)诱导糖尿病小鼠非增殖性糖尿病视网膜病变(NPDR)的改善作用及其机制。方法 采用STZ诱导小鼠发生糖尿病,进而建立糖尿病并发症NPDR实验动物模型,再给予EEDC进行干预。采用视网膜组织伊文思蓝渗漏实验观察NPDR小鼠中血-视网膜屏障(BRB)的破坏情况;采用real-time PCR(RT-PCR)检测视网膜组织中白细胞介素-6(IL-6)、IL-1β、肿瘤坏死因子(TNF-α)及早期生长反应因子(Egr-1)、组织因子(TF)、纤溶酶原激活物抑制剂1(Serpine 1)的基因表达;进一步采用酶联免疫实验(ELISA)检测血清中IL-1β、IL-6、TNF-α及TF、Serpine 1的量。结果 与对照组相比,模型组小鼠视网膜组织伊文思蓝渗漏量明显增加,EEDC能够减少视网膜组织伊文思蓝渗透量;EEDC能够显著降低模型小鼠视网膜组织中增加的IL-1β、IL-6、TNF-α及Egr-1、TF、Serpine 1的基因表达;EEDC能够明显下调模型小鼠血清中增加的IL-1β、IL-6、TNF-α及TF、Serpine 1的量。结论 EEDC具有改善STZ诱导小鼠NPDR的作用,其机制为通过抑制NPDR小鼠视网膜和血清中增加的炎性因子IL-1β、IL-6、TNF-α以及与凝血/纤溶相关基因TF、Serpine 1的基因表达,缓解BRB的破坏,从而发挥改善NPDR的作用。

Objective To observe the amelioration of ethanol extract from Dendrobium chrysotoxum (EEDC) on non-proliferative diabetic retinopathy (NPDR) induced by streptozotocin (STZ), and further to investigate its engaged mechanism. Methods NPDR was induced by STZ injection in C57 mice and then the diabetic mice were orally given EEDC. The retinal blood-retinal barrier (BRB) breakdown was evaluated using Evans blue leakage assay. The mRNA expression of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF) α, early growth response-1(Egr-1), tissue factor (TF), and Serpine 1 in retinas was detected by real-time PCR. The amount of IL-1β, IL-6, TNF-α, TF, and Serpine 1 in serum was detected by enzyme-linked immunosorbent assay (ELISA). Results EEDC at both doses reduced the increased Evans blue leakage in STZ-induced NPDR in mice. Results of Real-Time PCR showed that EEDC reduced the increased retinal mRNA expression of IL-1β, IL-6, TNFα and Egr-1, TF, Serpine 1 in STZ-induced NPDR in mice. ELISA results also confirmed that EEDC reduced the increased serum levels of IL-1β, IL-6, TNF-α, TF, and Serpine 1 in STZ-induced NPDR in mice. Conclusion EEDC could ameliorate the STZ-induced NPDR in mice via inhibiting retinal BRB breakdown by reducing the expression of pro-inflammatory cytokines including IL-1β, IL-6, TNF-α, and coagulation-fibrinolysis related signals such as TF and Serpine 1.

国家自然科学基金资助项目(81173517)