去水淫羊藿素对大鼠视网膜缺血/再灌注损伤的保护作用

Protective effects of icaritin on retinal ischemia/reperfusion injury in rats

目的研究去水淫羊藿素(ICT)对大鼠视网膜缺血/再灌注损伤是否具有保护作用,并初步探讨其作用机制。方法将40只SD大鼠采取随机数表法分为5组(n=8),通过夹闭一侧颈总动脉的方法构建大鼠视网膜缺血/再灌注(I/R)模型。分别于夹闭前,一次性经腹腔注射不同剂量(1.0 mg/kg、2.0 mg/kg、4.0 mg/kg)ICT;假手术组及模型组给予等体积生理盐水腹腔注射;假手术组只分离不夹闭,模型组与药物组建立视网膜I/R模型。各组分别在夹闭前、缺血30 min时行视网膜电流图(ERG)、眼底照相检查以及再灌注1 h后行ERG、眼底荧光血管造影(FFA)检查。再灌注6 h后获取视网膜,通过免疫印迹法检测白介素10(IL-10)蛋白表达水平。结果与模型组比较,ICT治疗组能显著改善ERG的a波、b波振幅降低,使后极部视网膜缺血动脉明显扩张,并且能升高视网膜I/R损伤后视网膜组织IL-10蛋白表达水平[(1.02±0.44)vs(0.47±0.21)],差异有统计学意义(P<0.05)。结论 ICT对视网膜缺血/再灌注损伤具有保护作用,其保护机制可能与上调抗炎细胞因子IL-10蛋白表达水平,抑制炎症反应有关。

Objective To explore the protective effects of icaritin（ICT） on retinal ischemia/reperfusion injury in rats and its potential mechanism. Methods Forty Sprague-Dawley rats were assigned into the five groups according to random number tables, with 8 cases in each group. The model of retinal ischemia/reperfusion injury was induced by the ligation of the common carotid artery unilaterally. Respectively, these rats were randomized to receive intraperitoneal injection of saline, at the dosage of 1.0 mg/kg, 2.0 mg/kg, 4.0 mg/kg of ICT before the induction of retinal I/R injury.The rats in the sham group were isolated without ligation of the common carotid artery, and the retinal I/R model was established in the model group and the drug group. Electroretinography（ERG） and fundus photography were used to assess functional changes in retina before and 30 minutes after ligation. One hour after reperfusion, ERG and fluorescein fundus angiography（FFA） were performed. After 6 h of reperfusion, the rats were sacrificed and the eyeballs were extracted for retina. The expression of interleukin 10（IL-10）, one of anti-inflammatory mediators was quantified by Western blot analysis. Results Compared with the model group, the ICT groups ameliorated notably the decrease of the amplitudes of the a-and b-waves and significantly dilate retinal vessels. Besides, the level of IL-10 in the retinal tissue after retinal I/R damage increased, especially in 2.0 mg/kg ICT group（P〈0.05）. Conclusion ICT has a protective effect in retinal ischemia/reperfusion injury, possibly by increasing the expression of IL-10 and suppressing inflammation.