表没食子儿茶素没食子酸酯对小鼠角膜碱烧伤的治疗作用

Efficacy of epigallocatechin gallate in treatment of alkali burn injury of murine cornea

目的：研究表没食子儿茶素没食子酸酯（EGCG）对角膜碱烧伤的治疗作用。方法：制作C57BL／6J小鼠角膜碱烧伤模型，实验分为EGCG组和磷酸盐缓冲液（ PBS）组，分别给予腹腔注射EGCG溶液或者等量PBS，裂隙灯显微镜和组织病理学观察和评价小鼠角膜上皮修复、新生血管生长以及炎症反应程度，免疫组织化学染色和实时定量PCR法检测血管内皮生长因子（ VEGF）的表达，髓过氧化物酶定量测定评价中性粒细胞的浸润程度。结果：EGCG组小鼠角膜上皮修复速率显著大于PBS组，碱烧伤后第1、3、7天的差异有统计学意义（均P＜0．05）。EGCG组和PBS组小鼠均见新生血管生长，在碱烧伤后第3、7、14天EGCG组新生血管评分和角膜切片中新生血管数量均显著低于PBS组， EGCG组的VEGF蛋白表达量在碱烧伤后第3、7天显著低于PBS组，EGCG组VEGFmRNA表达量在碱烧伤后第1、3、7天均低于PBS组，差异均有统计学意义（均P＜0．05）。碱烧伤后第7、14天EGCG组的炎症指数低于PBS组，第3、7、14天EGCG组角膜组织切片中中性粒细胞浸润数量和髓过氧化物酶检测值均低于PBS组，差异均有统计学意义（均P＜0．05）。结论：腹腔注射EGCG可有效促进碱烧伤后小鼠角膜上皮修复，抑制新生血管形成和炎症细胞浸润。

Objective：To evaluate the efficacy of epigallocatechin gallate （ EGCG） in treatment of corneal alkali burn injury in mice .Methods：Corneal alkali burn injury was induced by sodium hydroxide method in C 57BL/6J mice.The mice with cornea burns were treated intraperitoneally with EGCG solution or phosphate buffer solution （ PBS ） respectively . The healing of corneal epithelium , the formation of corneal neovascularization （ CNV ） and the inflammation reaction were assessed by slit-lamp microscopy and histological examination . Expression of vascular endothelial growth factor （ VEGF ） mRNA and protein in cornea was evaluated by real-time reverse transcription polymerase chain reaction （ RT-PCR ） and immunohistochemistry , respectively .Myeloperoxidase （ MPO ） assay was used to quantitatively evaluate the polymorphonuclear neutrophils （ PMNs ） infiltration in the corneas . Results： The healing rate of corneal epithelium in EGCG group was significantly higher than that of PBS group at d1, d3 and d7 after treatment （ d1： 41.0% ±13.0% vs 23.8% ± 7.6%;d3：76.6%±7.5% vs 61.2%±6.8%; d7： 87.8%±8.5% vs 74.0%± 9.1%;all P 〈0.05 ） .The CNV scores and the number of CNV in the corneal sections of EGCG group were significantly lower than those of PBS group at d 3 , d7 and d14 after treatment （ CNV score： d3： 1.1 ±0.5 vs 6.6 ±1.0; d7： 1.3 ±0.3 vs 8.1 ±1.0;d14：0.9 ±0.2 vs 9.2 ±1.1; CNV number： d3：1.68 ±0.61 vs 2.92 ±0.95; d7：4.80 ±1.36 vs 7.92 ±1.28;d14：3.64 ±0.71 vs 5.88 ±0.76;all P 〈0.05 ） .The expression of VEGF protein at d3 （0.19 ±0.05 vs 0.45 ±0.08） and d7 （0.42 ±0.07 vs 0.84 ±0.09 ） , the expression of VEGF mRNA at d 1 , d3 and d7 in EGCG group were significantly lower than those in PBS group （ all P 〈0.05 ） .Compared to PBS group, the inflammatory index at d3 （3.2 ±0.4 vs 3.7 ±0.5） and d7 （2.3 ±0.5 vs 4.0 ±0.0 ） , the number of PMNs in the corneal sections and the MPO values at d 3 , d7 and d14 in EGCG group were significantly decreased （ PMNs： d3： 34.5 ±15.7 vs 90.0 ±28.8;d7：17.1 ±11.4 vs 54.9 ±25.9;d14：12.8 ±4.6 vs 39.0 ±17.9; all P 〈0.05 ） .Conclusion： In the murine corneal alkali burn model , intraperitoneal injection of EGCG solution can promote the healing of corneal epithelium , inhibit the formation of CNV and reduce the inflammatory cell infiltration in the corneas .