枸杞子提取液对单眼视觉剥夺性弱视大鼠视网膜的保护作用

Neuroprotective effects of Lycium barbarum on the retina of monocular visual deprived amblyopia in rats

目的:观察枸杞子提取液(LBA)对视觉剥夺性弱视大鼠视网膜的保护作用,并探讨其可能的作用机制。方法:新生Wistar大鼠21只,雌雄不限。随机分为空白对照组(5只)、治疗对照组(8只)及治疗组(8只)。1周后,缝合治疗对照组及治疗组大鼠单侧眼睑,建立动物模型。4周后,拆除手术缝线,并给予治疗组大鼠LBA1mg/kg治疗,每日一次。空白对照组及治疗对照组自由进食。6周后处死所有大鼠,摘取眼球。应用伊红-苏木素(HE)染色观察视网膜的改变;应用TUNEL检测视网膜细胞凋亡的状况;应用免疫组织化学检测Bcl-2蛋白(Bcl-2)、Bax蛋白(Bax)及caspase-3在视网膜细胞的表达。结果:与空白对照组相比,治疗对照组Bax及caspase-3的表达明显增强(P<0.05),Bcl-2的表达明显减弱(P<0.05);与治疗对照组比较,治疗组Bax及caspase-3的表达均明显减弱(P<0.05);而Bcl-2的表达明显增强(P<0.05)。结论:LBA对视觉剥夺性弱视大鼠视网膜在视觉发育可塑期内可能具有保护作用,其机制可能与上调Bcl-2、下调Bax及抑制caspase-3的表达,减少细胞凋亡有关。

Objective： To observe the retinal changes of monocular visual deprived amblyopia in rat, and to investigate of the neuroprotective effect of the aqueous extract of dried fruits of Lycium barbarum （LBA） on the rat and possible mechanism. Methods： A total of 21 newnatal Wistar rats were randomly divided into 3 groups, blank control （BC, 5 rats）, treatment control （TC, 8 rats） and treatment group （TG, 8 rats）. After postnatal 1 week, the monocular palpebra was sewed in TC and TG to make the rat model. After postnatal 4 weeks, the suture was dismantled. TG started to be fed 1 mg/kg LBA daily; both BC and TC were fed normally. After postnatal 6 weeks, all the rats were executed to remove selected eyeballs. Then retinal cells necrosis and apoptosis was assessed by the methods of HE staining, TUNEL detection, the expression of Bcl-2, Bax and caspase-3 was detected by immunohistochemistry. Results ： The positive expression of Bax and caspase-3 in TC was significantly higher than that in BC （ P 〈 0. 05 ）, and Bcl-2 in TG was significantly lower （ P 〈0. 05）. Compared with TC, the positive expression of Bax and caspase-3 were significantly lower in TG （P 〈 0.05 ）, and the positive expression of Bcl-2 was significantly higher in TG （P 〈 0. 05 ）. Conclusion： LBA might have neuropro- tective effect on the retina of monocular visual deprived amblyopia in rat in the critical period of visual plasticity during development, which might be related with up-regulating the expression of Bcl-2, negative regulating the expression of Bax, inhibiting the expression of caspase-3 and reducing cellular apoptosis.