枸杞叶、果的抗氧化和抗DNA损伤活性研究

摘要

Contents of polysaccharides,polyphenols and flavonoids in leaves and fruits of Lycium barbarum were determined by phenol-sulfuric acid method,Folin-Ciocalteu reagent method and AlCl3 colorimetric method,respectively.Antioxidant capacities of different extracts from L.barbarum were evaluated by ABTS [2,2'-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt] and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays.In addition,the inhibitory activity against DNA damage of leaves and fruits were analyzed using plasmid DNA method.Concentrations of bioactive constituents varied across different extracts from leaves and fruits.Antioxidant activities of leaves were higher than those of fruits.Methanol extract from leaves and fruits possessed the lowest EC50 value (ABTS:0.69,2.04;DPPH:0.03,0.52),followed by ethanol extract (ABTS:0.70,2.08;DPPH:0.04,0.57) and aqueous extract (ABTS:0.95,2.08;DPPH:0.05,0.62),which suggested the highest antioxidant activity of methanol extract.DNA damage protection activity of methanol extract from leaves was higher than that from fruits.Antioxidant capacity and inhibitory activity against DNA damage of leaves and fruits was possibly attributed to their polyphenols and flavonoids.The present research was helpful for the scientific exploitation and comprehensive utilization of L.barbarum resource.%采用苯酚-硫酸比色法、Folin-Ciocalteu比色法、A1C13显色法测定了枸杞叶、果不同溶剂提取物中活性成分的含量,采用ABTS和DPPH方法分析了枸杞叶、果提取物的抗氧化活性,采用质粒DNA方法研究了抗DNA损伤活性.结果表明:枸杞叶、果不同溶剂提取物中活性成分的含量不同.枸杞叶的抗氧化活性高于枸杞果.枸杞叶、果甲醇提取物的EC50值最低(ABTS:0.69,2.04;DPPH:0.03,0.52),乙醇提取物次之(ABTS:0.70,2.08;DPPH:0.04,0.57),水提物最高(ABTS:0.95,2.08;DPPH:0.05,0.62),说明甲醇提取物具有较强的抗氧化能力.枸杞叶甲醇提取物的DNA保护作用强于枸杞果.多酚和黄酮类化合物可能是枸杞叶、果抗氧化和抗DNA损伤活性的物质基础.本研究为枸杞资源的科学开发和综合利用提供了参考.