槲皮素、异鼠李素逆转体外HDL氧化修饰的实验研究

Inhibitory effects of quercetin and isorhamnetin on oxidative modification of HDL induced by Cu2+/Fe2+ in vitro

摘要:

目的观察槲皮素(Quercetir,Que)和异鼠李素(Isorhamnetin,Iso)在体外对已受到Cu2 、Fe2 氧化修饰的人血浆高密度脂蛋白(high density liprotein,HDL)的作用.方法采用一次性密度法分离正常人血浆HDL,用Cu2 ,Fe2 进行体外氧化修饰.抗氧化组在修饰后6h加Que或Iso(100mol/L)作用不同时间(4,8和16 h).分别检测HDL中脂质过氧化物丙二醛(MDA)、维生素E(VitE)含量及超氧化物歧化酶(SOD)活性.结果100μmol/L Que和Iso作用4,8h后可分别明显抵制Fe2 -Ox-HDL,Cu2 -Ox-HDL中MDA生成(P＜0.001).Que和Iso作用8,16 h后可分别提高Cu2 -Ox-HDL,Fe2 -Ox-HDL中SOD活性(P＜0.001);明显延缓VitE含量降低(P＜0.05).结论Que和Iso均对已受到Cu2 ,Fe2 氧化修饰的HDL具有明显的抑制作用,但对Cu2 ,Fe2 氧化修饰的HDL,槲皮素、异鼠李素的作用存在差异.Que和Iso的作用机制可能与其抗自由基氧化有关,提示该类物质是一种良好的抗氧化剂,对As的防治有一定的运用价值.

Abstract:

Objective: To observe the effects of quercetin (Que) and isorhamnetin (Iso) on the oxidative modification of high density lipoprotein (HDL) induced by Cu2+ and Fe2+ in vitro. Methods: Human HDL was prepared by one-step ultracentrifuge and oxidized by Cu2+ and Fe2+ in vitro. HDL was incubated with Que or Iso (100 μmol/L) for different time (4, 8 and 16 h) after 6 h oxidation by Cu2+ and Fe2+. The content of the production of lipid peroxide (MDA), vitamin E (vit E) and activity of superoxide dismutase (SOD) in oxidized high density lipoprotein (OX-HDL) were determined. Results: Compared with OX-HDL group, MDA production in Fee2+-OX-HDL, Cu2+-OX-HDL decreased significantly after 4 h and 8 h treatment with Que or Iso respectively (P ＜0.001). Que and Iso also markedly elevated vite level and SOD activities in Fe2+-OX-HDL,Cue2+-OX-HDL after 8h and 16 h treatment (P ＜0.001, P ＜0.05), respectively. Conclusions: Que and Iso obviously inhibit oxidative modification of HDL already induced by Cu2+ and Fe2+. But for Fe2+-OX-HDL Cu2+-OX-HDL, there are some differences between Que and Iso treatment. The results suggest that the mechanism of the protective effect of both Que and Iso on oxidative modification of HDL may be associated with the inhibition of generation of oxygen free radicals and with the prevention of inactivation of SOD or vitE reducing.