槲皮素对大鼠角膜碱烧伤后瘢痕形成的影响

Effect of quercetin on the scar formation after the alkal cauterization in rat's cornea

目的探讨槲皮素(quercetin,QU)在大鼠角膜碱烧伤后抑制瘢痕形成的可能作用及其机制。方法建立SD大鼠角膜碱烧伤模型,以右眼为实验眼。SD大鼠随机分为5组,对照组术后予眼膏基质,QU治疗组分别予2.5、5、10、20 g/kg QU眼膏。术后裂隙灯显微镜检查,记录角膜混浊程度。于术后第4、7、14、21、28天处死动物,行组织学染色观察炎性细胞的浸润;Masson三色染色法观察角膜基质层胶原纤维的排列和增殖;免疫组织化学方法检测各组角膜组织中转化生长因子-β1(TGF-β1)和转化生长因子-βⅠ受体(TGF-βRⅠ)的表达。结果术后QU治疗组的角膜组织病理改变及角膜混浊程度较对照组轻,10 g/kg QU和20 g/kg QU组抑制角膜瘢痕形成作用强于2.5 g/kg QU和5 g/kg QU组,且10 g/kg QU和20 g/kg QU组间比较无统计学差异。HE染色和Masson染色均显示QU治疗组角膜基质层胶原纤维的密度较对照组低。碱烧伤后第7天TGF-β1和TGF-βRⅠ的表达达高峰,之后逐渐减少,接近正常水平;10 g/kg QU和20 g/kg QU组抑制TGF-β1和TGF-βRⅠ的表达作用强于2.5 g/kg QU和5 g/kg QU组,且10 g/kg QU和20 g/kg QU组间比较无统计学差异。结论QU眼膏具有一定程度减轻瘢痕化的作用,尤以10 g/kg浓度最佳。QU可能通过抑制TGF-β1和TGF-βRⅠ的表达发挥其作用。

Objective To explore the possible effect and mechanism of quercetin （QU） in inhibiting scar formation after the alkali burn of rat＇s cornea. Methods We established corneal alkali-burn model on right eyes of the SD rats. The rats were divided into five groups randomly. The control group received blank ophthalmic gel; the QU treatment groups received 2.5, 5, 10, or 20 g/kg quercetin ophthalmic gel, respectively. The rats were checked by slit-lamp microscope every day for the degree of corneal opacity, then were killed on day 4, 7, 14, 21 and 28 after operation. The infiltration of the inflammatory cells was observed by histology, the arrangement and proliferation of the collagen fibers in the corneal stroma were observed by Masson trichrome staining. The expression of transforming growth factor-β1 （TGF-β1） and receptor of transforming growth factor-β1 （TGF-OR Ⅰ ） in cornea was observed by immunohistochemical method. Results The corneal opacity was less severe in the QU treatment groups than in the control group （P〈0. 05）. Corneal scar was inhibited better in 10 g/kg QU and 20 g/kg QU groups than in 2. 5 g/kg and 5 g/kg QU groups, and 10 g/kg and 20 g/kg QU groups had no significant differences （P〉0.05）. HE and Masson staining showed that the density of corneal stroma collagen fibers in the QU treatment groups was lower than that in the control group. The expression of TGF-β1 and TGF-βR Ⅰ reached the peak on day 7 after alkali burn, and then decreased slowly, which was close to the normal level. The expression of TGF-β1 and TGF-βR Ⅰ was inhibited better in 10 g/kg and 20 g/kg QU groups than in 2.5 g/kg and 5 g/kg groups, and 10 g/kg and 20 g/kg QU groups had no significant differences （P〉0.05）. Conclusion QU ophthalmic gel can reduce formation of corneal scar to a certain extent, 10 g/kg is the optimal concentration. QU may play its role by inhibiting the expression of TGF-βⅠ and TGF-βR Ⅰ .