中文摘要：

目的比较不同锁阳提取物体外抗氧化活性及对次黄嘌呤/黄嘌呤氧化酶（hypoxanthine/xanthine oxidase,HPX/XO）诱导细胞损伤的保护作用。方法通过建立XO/XTT氧自由基生成体系和XO致尿酸生成反应,以及HPX/XO诱导的细胞氧化损伤模型,分别研究不同锁阳提取物的自由基清除能力,对HPX活性的干预作用,和对氧化损伤细胞的保护作用。结果 100、10、1μg/ml锁阳乙酸乙酯和甲醇提取物均能显著地清除自由基,而各浓度的锁阳二氯甲烷和水提物没有明显的清除自由基能力。锁阳乙酸乙酯和甲醇提取物对细胞氧化损伤模型显示明显的保护作用,可显著提高细胞存活率,但不能明显抑制XO活性。结论锁阳抗氧化有效部位主要富集在乙酸乙酯与甲醇提取相中,具有良好的抗氧化作用,清除氧自由基是其主要机制之一。

英文摘要：

Objective To investigate the in vitro antioxidant activities of different extracts of Cynomorium songaricum and their protective effects against hypoxanthine/xanthine oxidase （HPX/XO）-induced cell in- jury through a comparative study. Methods Different extracts of Cynomorium songaricum were evaluated with regard to their free radical-scavenging abilities, inhibitory effects on XO, and protective effects a- gainst oxidative cell injury using an XO/XTT oxygen free radical-generating system, the uric acid produc- tion catalyzed by XO, and an HPX/XO-induced oxidative cell injury model, respectively. Results Ethyl acetate and methanol extracts of Cynomorium songaricum （100 μg/ml, 10μg/ml, and 1μg/ml） could scavenge free radicals significantly, but different concentrations of dichloromethane and water extracts of Cynomorium songaricum did not exhibit significant abilities to scavenge free radicals. The ethyl acetate and methanol extracts of Cynomorium songaricum show protective effects on the oxidative cell injury model, increasing the survival rate of cells significantly, but could not inhibit the activity of XO significantly. Conclusion The antioxidant fractions of Cynomorium songaricum are mainly enriched in the ethyl acetate and methanol phases, and have good antioxidant effects, which can be achieved through oxygen free radical scavenging.