异鼠李素及橙皮甙抑制LDL氧化修饰作用的研究

目的:研究黄酮类中药异鼠李素及橙皮甙是否具有抑制LDL氧化修饰的作用。方法:按一次性密度梯度超速离心法分离人血清LDL,分别加入5.0μmol/L异鼠李素及橙皮甙与LDL温育3 h,然后利用Cu2 介导体外氧化修饰脂蛋白的方法,观察LDL氧化修饰不同时间,其A234、REM、TBARS及蛋白质羰基的动力学改变,并与对照组比较。结果:Cu2 介导LDL氧化修饰时,在2、4、6、8、12及24 h后,其A234、REM、TBARS及蛋白质羰基含量均逐步增加;加入5.0μmol/L异鼠李素及橙皮甙的实验组,Cu2 LDL的氧化修饰分别延迟2~4 h和2 h,其A234、REM、TBARS及载脂蛋白羰基含量较对照组降低;异鼠李素实验组分别较对照组降低23.5%~40.4%、20.5%~37.7%、18.6%~30.3%及20.1%~52.4%(P<0.001);橙皮甙实验组分别降低11.1%~21.2%、9.2%~28.3%、13.7%~21.3%及5.0%~43.8%(P<0.001,P<0.01,P<0.001及P<0.05)。结论:异鼠李素及橙皮甙均可抑制Cu2 诱导的LDL的氧化修饰,且异鼠李素的抗氧化作用较及橙皮甙强。

Inhibitory Effect of Isorhamnetin and Heperidin on LDL Oxidation Induced by Cu2+

OBJECTIVE: To evaluate the inhibitory effect of Isorhamnetin and Hesperidin on the LDL oxidation induced by Cu2+. METHODS: The serum LDL was isolated by the one step density gradient ultracentrifugation. The LDL oxidation was induced by Cu2+ in vitro for different time periods. Isorhamnetin and Hesperidin at 5 micromol/L were added respectively, as the experimental groups, 3 hours before oxidation. The oxidation of LDL in experimental and control groups was identified by measuring A234 , REM, TBARS and protein carbonyls content. RESULTS: The values of A234, REM, TBARS and protein carbonyls formation increased gradually during LDL oxidation induced by Cu2+ in vitro. During LDL oxidation induced by Cu2+ in vitro and incubation with each of Isorhamnetin and Hesperidin, the kinetic changes of A234 , REM, TBARS and protein carbonyls formation showed lag phases of 2-4 h and 2 h respectively, and the corresponding values for each of the agents treated group were reduced by 23.5%-40.4%, 20.5%-37.7%, 18.6-30.3% and 20.1%-52.4% (P < 0.001); and 11.1%-21.2%, 9.2%-28.3%, 13.7%-21.3% and 5.0%-43.8% respectively (P < 0.001, P < 0.01, P < 0.001 and P < 0.05). CONCLUSION: It suggests that Isorhamnetin and Hesperidin can substantially inhibit LDL oxidation, and Isorhamnetin has antioxidation ability stronger than Hesperidin.