红毛五加叶水提液对羟自由基清除率的测定

[目的]测定红毛五加叶水提液对羟自由基的清除率并评价其抗氧化活性。[方法]利用Fenton反应产生羟自由基,用二甲亚砜（DMSO）捕获羟自由基并与之反应生成甲醛,甲醛经2,4-二硝基苯肼衍生成相应的苯腙,通过HPLC检测加或不加样品时该苯腙的峰面积的变化,从而计算红毛五加叶水提液对羟自由基的清除率。色谱条件：色谱柱为Diamonsil C18（250 mm×4.6 mm5,μm）,流动相为乙腈-水（65∶35,V/V）,流速为0.8 ml/min,检测波长为365 nm。[结果]Fenton反应体系为2.0 mmol/L Fe2＋＋107.7 mmol/L H2O2＋225.2 mmol/L DMSO;在该反应体系中红毛五加叶水提液清除羟自由基的IC50为0.67 mg/ml（即每1 ml含药材量为0.67 mg）;红毛五加叶总皂苷是清除羟自由基的活性成分。[结论]红毛五加叶水提液能够清除Fenton反应产生的羟自由基,具有较强的抗氧化活性。

Determination on Scavenging Activity of Acanthopanax gimldiiLeaves Aqueous Extract to Hydroxyl Radicals

[Objective] The aim was to determine the hydroxyl radicals scavenging capacity by the leaves aqueous extract of Acanthopanax giraldii Harms.for its antioxidant activity evaluation.[Method] The proposed method employed the reaction between hydroxyl radicals generated by the Fenton system and dimethyl sulfoxid(DMSO) to form formaldehyde,which then reacted with 2,4-dinitrophenylhydrazine(DNPH) to produce the corresponding hydrazone(HCHO-DNPH).The hydroxyl radicals scavenging rate was calculated by the HPLC peak areas of HCHO-DNPH in the above reaction system with or without A.giraldii as a scavenger.The chromatographic conditions included a Diamonsil C18 column(250 mm × 4.6 mm,5 μm),a mobile phase consisting of acetonitrile-water(65∶35,V/V),a flow rate of 0.8 ml/min and ultraviolet detection at 365 nm.[Result] The optimized Fenton system for HCHO-DNPH generation was 2.0 mmol/L Fe2+ + 107.7 mmol/L H2O2 + 225.2 mmol/L DMSO.The half-scavenging concentration(IC50) of the A.giraldii leaves aqueous extract was 0.67 mg/ml(i.e.0.67 mg crude leaves to 1 ml volumes).The total saponins of A.giraldii leaves were one part of active ingredients.[Conclusion] The A.giraldii leaves aqueous extract is a potent hydroxyl radicals scavenger with potential antioxidant activity.