当归多糖对青光眼大鼠视网膜神经细胞的保护作用及其机制

目的：探讨当归多糖对青光眼致大鼠视网膜神经细胞损伤的保护作用，并阐明其机制。方法：将84只SD大鼠随机分为对照组、模型组、阳性药组、低剂量当归多糖组、中剂量当归多糖组和高剂量当归多糖组，每组14只，采用烧灼烙闭巩膜上静脉法建立大鼠青光眼模型。检测各组大鼠眼压值；采用比色法测定大鼠视网膜组织中超氧化物歧化酶（SOD）活性及丙二醛（MDA）和一氧化氮（NO）水平；采用RT-PCR法和Western blotting法检测大鼠视网膜组织中Caspase-3 mRNA和蛋白表达水平。结果：与对照组比较，模型组大鼠各时间点眼压明显升高（P<0.05）；与模型组比较，不同剂量当归多糖组大鼠眼压明显降低（P<0.05）；与低剂量当归多糖组比较，高剂量当归多糖组大鼠眼压明显降低（P<0.05）。比色法测定，与对照组比较，模型组大鼠视网膜组织中SOD活性明显降低（P<0.05），MDA和NO水平明显升高（P<0.05）；与模型组比较，不同剂量当归多糖组大鼠视网膜组织中SOD活性明显升高（P<0.05），MDA和NO水平均明显降低（P<0.05）；与低剂量当归多糖组比较，高剂量当归多糖组大鼠上述指标差异均有统计学意义（P<0.05）。RT-PCR和Western blotting法检测，与模型组比较，不同剂量当归多糖组大鼠视网膜组织中Caspase-3 mRNA和蛋白表达水平明显降低（P<0.05）；与低剂量当归多糖组比较，高剂量当归多糖组大鼠视网膜组织中Caspase-3 mRNA和蛋白表达水平明显降低（P<0.05）。结论：当归多糖对青光眼模型大鼠的视网膜组织有保护作用，可以降低视网膜组织MDA和NO水平，升高SOD活性，同时降低视网膜组织中Caspase-3 mRNA和蛋白表达水平，这可能是当归多糖保护视网膜组织神经细胞的机制之一。

Protective effect of Angelica polysaccharide on retinal nerve cells in glaucoma rats and its mechanism

Objective:To investigate the protective effect of Angelica polysaccharide on the glaucoma-induced retinal neuronal injury,and to elucidate its mechanism.Methods:Eighty-four SD rats were randomly divided into control group,model group,positive drug group,low,middle and high doses of Angelica polysaccharide groups.The model of rat glaucoma was established by sclera sclerotherapy.The intraocular pressures (IOP) of rats in each group were measured.The superoxide dismutase (SOD) activities,malondialdehyde (MDA) contents and nitric oxide (NO) levels in retina tissue of the rats were measured by colorimetric assay.The expression levels of Caspase-3 mRNA and protein in retina tissue of the rats were observed by RT-PCR and Western blotting method.Results:Compared with control group,the IOP of the rats in model group at each time point were significantly increased (P＜0.05);compared with model group,the IOP of the rats in different doses of Angelia polysaccharide groups were significantly decreased (P＜0.05);compared with low dose of Angelica polysaccharide group,theIOP of the rats in high dose of Angelica polysaccharide group was significant decteased (P＜0.05).The levels of MDA and NO in the retina tissue of the rats in model group were higher than those in control group (P＜0.05),but the SOD activities were decreased (P＜0.05);compared with model group,the levels of MDA and NO in retinal tissue of the rats in different doses of Angelica polysaccharide group were significantly decreased (P＜0.05),and the SOD activities were significantly increased (P＜0.05);compared with low dose of Angelica polysaccharide group,the above indexed had significant differences in high dose of Angelica polysaccharide group (P＜0.05).Compared with model group,the expression levels of Caspase-3 mRNA and protein in different doses of Angelica polysaccharide groups were significantly decreased (P＜0.05);compared with low dose of Angelica polysaccharide group,the expression levels of Caspase-3 mRNA and protein were significantly decreased (P ＜ 0.05).Conclusion:Angelica polysaccharide has protective effect on the retinal tissue of glaucoma model rats,which can decrease the levels of MDA and NO in retina tissue and increase the activity of SOD and decrease the expression levels of Caspase-3 mRNA and protein in retina tissue.It may be one of the mechanisms of polysaccharide protecting in retinal tissue nerve cells.