鞣花酸改善糖尿病小鼠眼组织病变的研究

Research of pomegranate ellagic acid on ocular tissue lesions in diabetic mice

目的 观察石榴多酚鞣花酸(EA)干预对链脲佐菌素诱导的糖尿病小鼠眼组织病变的改善作用。方法 将28只KM小鼠按体质量随机分为正常组(8只)、模型组(10只)和实验组(10只)。模型组和实验组按50 mg·kg^(-1)的剂量多次腹腔注射链脲佐菌素构造糖尿病模型。造模成功后,实验组按50 mg·kg^(-1)^(-1)·d^(-1)的剂量灌胃给予5 mg·mL^(-1)EA,连续给药5周;其余2组均灌胃给予等量蒸馏水。用苏木精-伊红染色法观察眼组织尤其视网膜病理组织结构变化,用蛋白质印迹法检测小鼠眼组织中微管相关蛋白轻链3(LC3Ⅱ/Ⅰ)和选择性自噬接头蛋白(p62)蛋白的表达水平。结果 糖尿病小鼠眼组织病理损伤严重,鞣花酸干预后炎症、视网膜淤血均有较好的恢复。实验组、模型组和正常组的LC3Ⅱ/Ⅰ蛋白相对表达量分别为0.52±0.10,0.14±0.08和1.00±0.20,p62相对表达量分别为1.61±0.50,3.28±0.70和1.00±0.40,模型组的上述指标与正常组和实验组比较,差异均有统计学意义(均P<0.01)。结论 EA对糖尿病小鼠眼组织具有保护作用,可通过调节自噬蛋白,进而有效地改善眼组织病变。

Objective To observe the effect of pomegranate polyphenol ellagic acid(EA) on the pathological changes of eye tissue in streptozotocin-induced diabetic mice. Methods A total of 28 Kunming mice were randomly divided into normal group, model group and experimental group. The diabetic model was established by intraperitoneal injection of low dose streptozotocin according to 50 mg·kg^(-1) dose. After successful modeling, the mice in the experimental group were given ellagic acid by intragastric administration. Five weeks later, the eyeballs of the mice were taken according to the dose of 50 mg·kg^(-1)·d^(-1). The pathological changes of the eye tissue, especially the retina, were observed by hematoxylin-eosin staining, and the expression of microtubule associated protein 1 light chain 3(LC3Ⅱ/Ⅰ) and selective autophagic junction protein(p62) in the eye tissue was detected by Western blotting. Results The pathological results showed that the mouse eye tissue was seriously damaged, and the inflammation and retinal congestion were recovered after ellagic acid intervention. The relative expression levels of LC3Ⅱ/Ⅰ protein in experimental, model and normal groups were 0.52±0.10, 0.14±0.08 and 1.00±0.20, the relative expression levels of p62 were 1. 61 ± 0. 50,3. 28 ± 0. 70 and 1. 00 ± 0. 40,respectively. The above indexes of model group were compared with those of normal and experimental group and the differences were statistically significant( all P < 0. 01). Conclusion Ellagic acid has a protective effect on diabetic mice eye tissue and can effectively improve the pathological changes of eye tissue by regulating autophagy protein.