中文摘要：

采用水杨酸法、二苯代苦味基肼自由基（DPPH·）法和Fe3＋还原能力试验3种方法，对绞股蓝不同极性溶剂提取物进行体外抗氧化活性评价，以乙醇、石油醚、氯仿、乙酸乙酯、正丁醇和水为样品提取剂，以Vc作阳性对照。结果表明：除石油醚提取物外，绞股蓝各提取物都表现出较强的清除羟基自由基活性。其中粗多糖对羟基自由基的清除能力最强，半清除率浓度为0．203mg／mL；绞股蓝各提取物对DPPH自由基也有很强的清除作用。以乙乙酯萃取物清除能力为最强，半清除率浓度为0．008mg/mL。同时，以上提取物还对Fe3＋具有很强的还原能力，乙酸乙酯萃取物的还原力优于对照品Vc。

英文摘要：

Three methods, including salicylic acid, DPPH （2,2-diphenyl-1-picrylhydrazyl） and deoxidization Fe3 ＋, were used to evaluate the in vitro antioxidant activities of extracts from Gynostemma pentaphyUum using ethanol, petroleum ether, chloroform, ethyl acetate, n-butanol or water, and Vc was employed as a control. The results showed that with the exception of petroleum ether extract, the extracts had good scavenging activities for hydroxyl radical （·OH）, especially crude polysaccharide, which demonstrated the highest activitie and its half elimination ratio （ IC50 ） was 0. 203 mg/mL. The extracts possessed strong scavenging activities on DPPH radical, the effect of ethyl acetate extracts was the strongest and its IC50 value was 0. 008 mg/mL. Additionally, the obtained extracts had stronger deoxidize Fe3＋ ability, the activity of the ethyl acetate extracts was somewhat stronger than that of Vc.