目的 观察薯蓣皂苷元对核因子E2相关因子2（nuclear factor erythroid-2-related factor 2，Nrf2）mRNA表达及超氧化物歧化酶（Superoxide Dismutase，SOD）、谷胱甘肽过氧化物酶（Glutathione peroxidase，GSH-Px）、丙二醛（malondialdehyde，MDA）的影响，探讨其干预干性年龄相关性黄斑变性（age-related macular degeneration，AMD）氧化应激反应的机制。方法 将SD系大鼠随机分为空白组、碘酸钠组、乐盯组、薯蓣皂苷元低剂量组（100 mg·kg^-1）、薯蓣皂苷元中剂量组（200 mg·kg^-1）、薯蓣皂苷元高剂量组（400 mg·kg^-1），每组20只，雌雄各半。用碘酸钠60 mg·kg^-1造模，乐盯组90 g·kg^-1乐盯灌胃，薯蓣皂苷元低、中、高剂量组分别按100 mg·kg^-1、200 mg·kg^-1、400 mg·kg^-1灌胃给药。连续灌胃20天和30天后分别取10只（雌雄各半）进行取材和指标检测。结果 碘酸钠组大鼠视网膜组织形态学改变、Nrf2 mRNA表达及SOD、GXH-PX、MDA与空白组、乐盯组有显著差异（P < 0.05、P < 0.01），而乐盯组与空白组之间无明显差异（P > 0.05）。灌胃20天时，高中剂量组的Nrf2 mRNA表达、GSH-Px值和MDA值和高中低剂量组SOD值优于碘酸钠组（P < 0.05、P < 0.01），其中，高剂量组Nrf2 mRNA表达，高中剂量组SOD值、GSH-Px值和MDA值，与乐盯组、空白组无明显差异（P > 0.05）；灌胃30天时，高中低剂量组Nrf2mRNA表达、GSH-Px值、MDA值优于碘酸钠组（P < 0.05、P < 0.01），但高中剂量组优势更明显，与乐盯组、空白组无差异（P > 0.05）。结论 薯蓣皂苷元能够上调Nrf2mRNA表达，增加SOD、GXH-PX活性，降低MDA水平，干预干性AMD的发生。且其作用与剂量和时间具有一定相关性。

Objective To observe the effect of diosgenin on nuclear factor erythroid-2 related factor 2 (Nrf2)mRNA expression, superoxide dismutase (SOD), glutathione peroxidase (GXH-PX) and malondialdehyde (MDA), and to explore the mechanism of intervention of diosgenin on oxidative stress in dry AMD.Methods SD rats were randomly divided into blank group, sodium iodate group, Legume group, diosgenin low dose group (100 mg·kg^-1), diosgenin medium dose group (200 mg·kg^-1), and diosgenin high dose group (400 mg·kg^-1), with 20 rats in each group, half male and half female. The model was made with sodium iodate of 60 mg/kg, and the group with 90 g·kg^-1 was gavage with Legume, and the groups with low, medium and high dose diosgenin were given 100 mg·kg^-1, 200 mg·kg^-1 and 400 mg·kg^-1 respectively. After 20 days and 30 days of continuous gavage, 10 rats (half male and half female) were selected for sampling and index detection.Results There were significant differences in retinal morphology, Nrf2 mRNA expression, SOD value, GXH-PX value and MDA value between the sodium iodate group and the blank group (P < 0.05 and P < 0.01), while there were no significant differences between the blank group and the Legume group (P > 0.05). On day 20, The Nrf2mRNA expression, GSH-Px value and MDA value of high and low dose group were better than those of sodium iodate group (P < 0.05 and P < 0.01), Among them, Nrf2mRNA expression in the high dose group, SOD, GSH-Px and MDA values in the high and middle dose groups, There was no significant difference compared with Legume group and blank group (P > 0.05); On day 30, The Nrf2mRNA expression, GSH-Px value and MDA value in high dose, medium dose and low dose groups were better than those of sodium iodate group (P < 0.05 and P < 0.01), but the high dose and medium dose groups had more advantages. Compared with Legume group, blank group, there were no difference (P > 0.05).Conclusion Diosgenin can up-regulate Nrf2mRNA expression, increase SOD, GXH-PX activity, reduce MDA level, and intervene the occurrence of dry AMD. The effects were correlated with dose and time to some extent.