天然抗氧化剂与DNA的相互作用的研究

Studies on the Interaction between Natural Antioxidants and DNA

目的 :研究天然抗氧化剂与DNA的相互作用。方法 :以溴化乙锭 (ethidiumbromide ,EB)为荧光探针 ,考察天然抗氧化剂 (茶多酚、银杏提取物和竹叶提取物 )和多糖 (螺旋藻多糖、海藻多糖 1、海藻多糖 2 )对EB DNA体系的荧光强度的影响。结果 :茶多酚、银杏提取物、竹叶提取物的荧光抑制率与浓度之间呈线性关系且不存在饱和性 ,抑制率可达 95 %以上。荧光强度抑制率达 5. 0 %时 ,上述三种抗氧化剂的浓度较为接近 ,均约为 0 5mg/ml。而多糖的荧光抑制率具有饱和性 ,且抑制率相对很低 ,螺旋藻多糖、海藻多糖 1、海藻多糖 2对荧光强度的饱和抑制率分别为 16 . 6 % ,2 6 .1% ,32 . 6 %。结论 :天然抗氧化剂与EB DNA体系的DNA有不同的作用机制。

AIM:To study the interaction between natural antioxidants and DNA. METHOD:The influence of some three antioxidants and polysaccharides on the fluorescence intensity,with the fluorescent probe of ethidium bromide(EB),was investigated. RESULT:The inhibition rate of relative fluorescence intensity increased with increasing concentration of the three antioxidants. The concentration of three antioxidants was approximately 0.5 mg/ml when the inhibition rate of relative fluorescence intensity was 50%. Nevertheless,one treated with polysaccharide had a saturation character and the inhibition rate was lower. The saturaton inhibition rate of polysaccharide,polysaccharide I,polysaccharide II was 16.6%,26.1%,32.6%,respectively.CONCLUSION:The interaction mechanism between natural antioxidants and DNA proved to be different from that between polysaccharide and DNA.