杜仲木脂素对慢性青光眼大鼠视神经保护作用及SOD、MDA、Caspase-3表达的影响

Protective Effect of Eucommia Ulmoides Lignans on Optic Nerve and Influence on the Expressions of SOD,MDA and Caspase-3 in Chronic Glaucoma Rats

目的:探讨杜仲木脂素对慢性青光眼大鼠视神经保护作用及超氧化物歧化酶(SOD)、丙二醛(MDA)、半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)表达的影响。方法:将90只SD大鼠随机分成5组:对照组、模型组、杜仲木脂素低、中、高剂量组(200,400,800 mg·kg^(-1)),每组18只;模型组、杜仲木脂素低、中、高剂量组建立慢性青光眼模型,建模成功后,杜仲木脂素低、中、高剂量组给予相应药物灌胃,1次/d,持续12周,模型组及对照组给予等体积的生理盐水。试验结束后,测定各组大鼠眼压、视网膜细胞凋亡水平、视网膜SOD和MDA水平,实时荧光定量逆转录-聚合酶链反应(RT-PCR)法及蛋白质印迹(Western Blot)法测定视网膜Caspase-3 mRNA和蛋白水平。结果:与对照组比较,模型组、杜仲木脂素各剂量组大鼠眼压水平、视神经细胞凋亡率、视网膜MDA、视网膜Caspase-3 mRNA和蛋白水平升高(P<0.05),视网膜SOD水平降低(P<0.05);与模型组比较,杜仲木脂素低、中、高剂量组眼压水平、视神经细胞凋亡率、视网膜MDA、视网膜Caspase-3 mRNA和蛋白水平降低(P<0.05),视网膜SOD水平升高(P<0.05);且随着杜仲木脂素剂量的增加,杜仲木脂素各剂量组眼压水平、视神经细胞凋亡率、视网膜MDA、视网膜Caspase-3 mRNA和蛋白水平逐渐降低(P<0.05),视网膜SOD水平逐渐升高(P<0.05)。结论:杜仲木脂素能明显降低慢性青光眼大鼠眼压及视神经细胞凋亡水平,降低视网膜氧化损伤反应;其机制可能与杜仲木脂素可抑制Caspase-3 mRNA和蛋白水平,进而抑制Caspase-3信号通路有关。

Objective: To investigate the protective effect of eucommia ulmoides lignans on optic nerve and the influence on the expressions of superoxide dismutase(SOD),malondialdehyde(MDA) and Caspase-3 in chronic glaucoma rats. Methods: Totally 90 SD rats were randomly divided into 5 groups: control group,model group,eucommia ulmoides lignans low,medium and high dose groups(200,400 and 800 mg·kg^(-1)) with 18 rats in each group. Chronic glaucoma model was established in the model group and the three eucommia ulmoides lignans groups. After the successful modeling,the three groups of eucommia ulmoides lignans were given corresponding drug by gavage,once a day for 12 weeks;the model group and the control group were given equal volume of normal saline.After the administration,the intraocular pressure,retinal cell apoptosis level,and omentum SOD and MDA levels of each group were measured,and real-time fluorescence reverse transcription(RT-PCR) and Western blot were used to determine retinal Caspase-3 mRNA and protein levels. Results: Compared with those in the control group,the intraocular pressure,optic nerve cell apoptosis rate,retinal MDA,and retinal Caspase-3 mRNA and protein levels in the model group and three groups of eucommia ulmoides lignans increased(P<0.05),and the retinal SOD level decreased(P<0.05);compared with those in the model group,the intraocular pressure,optic nerve cell apoptosis rate,retinal MDA and retinal Caspase-3 mRNA and protein levels in three eucommia ulmoides lignans groups decreased(P<0.05),and the retinal SOD level increased(P<0.05);with the increase of eucommia ulmoides lignans dosage,the intraocular pressure,optic nerve cell apoptosis rate,retinal MDA and retinal Caspase-3 mRNA and protein levels in eucommia ulmoides lignans groups decreased(P< 0.05),and the retinal SOD level increased(P < 0.05). Conclusion: Eucommia ulmoides lignans can significantly reduce intraocular pressure and apoptotic level of optic nerve cells in rats with chronic glaucoma,and reduce the oxidative damage of retina. The mechanism is related to the inhibition of Caspase-3 mRNA and protein levels by eucommia ulmoides lignans resulting in the inhibition of Caspase-3 signaling pathway.