槲皮素及异槲皮素、芦丁抗自由基活性的比较研究

目的评价3种黄酮类同系化合物槲皮素及其单糖苷异槲皮素和双糖苷芦丁的体外抗自由基作用,进一步研究其构效关系。方法采用H2O2/Fe2 体系,通过Fenton反应生成羟自由基(·OH);采用邻苯三酚自氧化法产生超氧阴离子(O2-)。利用·OH造成肝细胞脂质过氧化以及红细胞膜破裂,观察受试化合物的保护作用,并计算IC50。结果在以上4种体外模型中,3种药物均表现出极强的清除自由基能力。在·OH以及O2-清除实验中,抗氧化活性顺序为芦丁>异槲皮素>槲皮素;在抑制肝匀浆脂质过氧化及红细胞膜破裂实验中,抗氧化活性顺序为槲皮素>异槲皮素>芦丁。结论3种受试黄酮类化合物均具有十分强大的自由基清除作用,且呈现明显的剂量依赖性和糖基结构依赖性,在不同的实验体系中其抗自由基活性强弱顺序不同。

Comparative study on in vitro anti-free radical activities of quercetin,isoquercetin, and rutin

Objective To assess in vitro anti-free radical activities of three flavonoids:quercetin,itsmonoglycoside isoquercetin, and diglyeoside rutin,and further investigate their structure-effect rela-tionship.Methods Hydroxyl free radical(·OH)was generated using H202/Fe2+system via Fenton reaction, superoxide anion (02 7) using pyrogallol auto-oxidation method. Hepatocellular lipidperoxidation and the rupture of RBC membrane were caused by·OH.IC50 was calculated and used toexamine the anti-free radical activity.Results Among above four different in vitro models threeflavonoids showed extremely potent free radical-scavenging effects.Rutin demonstrated the greatestpotency in hydroxyl free radical and superoxide anion(027)models and quercetin demonstrated the lowestwhile the reversed Results was observed in·OH-caused heDatocellular lipidperoxidation and·OH-causedrupture of RBC membrane models.Conclusion Three flavoniods have potent anti-free radical effects in adose-and glycosyl structure-dependent manner.The anti-free radical activity potency may differ dependingon employed experiment system.