藿香蓟挥发油抗氧化活性研究

目的:观察藿香蓟挥发油的体外抗氧化活性.方法:用95％乙醇将藿香蓟挥发油配制成不同质量浓度(0.4,0.8,1.2,1.6,2.0 g·L-1)溶液,采用二苯代苦味酰自由基(DPPH·)法、2,2′-联氨-双(3-乙基苯并噻唑啉-6-磺酸)(ABTS+·)法和铁氰化钾还原法测定不同浓度挥发油的抗氧化能力.结果:不同浓度的藿香蓟挥发油对ABTS+·,DPPH·的清除能力及对铁离子还原能力强弱顺序为:2.0 g·L-1＞1.6 g·L-1＞1.2 g·L-1＞0.8 g'L-1 ＞0.4 g·L-1,其中对ABTS+·的清除能力较强,最高可达64.63％,但对DPPH·清除能力较弱,仅为19.61％.结论:藿香蓟挥发油具有较强的ABTS+·清除能力和还原能力,但清除DPPH·能力较弱,同时其抗氧化能力均与其浓度有关,可作为天然抗氧化剂及功能性食品的开发资源.

Antioxidant Activity of Essential Oils of Ageratum conyzoides

Objective: To study the antioxidant activity of essential oils of Ageratum conyzoides. Method: The essential oils of A. conyzoides were preparated into different doses (0.4,0.8,1.2,1.6,2.0 g·L^-1) with 95% ethanol. And the antioxidant activities were studied using DPPH assay, ABTS⁺·assay and reducing power assay. Result: The reducing power of iron ion and the scavenging activities of ABTS⁺·radical and DPPH radical were enhanced while the concentration of oil was increased(in the sequence of 2.0 g·L^-1>1.6 g·L^-1>1.2 g·L^-1>0.8 g·L^-1>0.4 g·L^-1). The ABTS⁺·radical scavenging rate reached to 64.63%, but the maximal DPPH radical scavenging rate just reached to 19.61%. Conclusion: The essential oils of A. conyzoides showed good activities on both scavenging ABTS⁺·radical and reducing power, but low activity on scavenging DPPH radical. All antioxidant activity showed a concentration-effect relationship. The essential oils can be employed as natural antioxidants and health care products.