槲皮素、芦丁及葛根素抑制LDL氧化修饰作用的研究

目的：研究黄酮类中药槲皮素、芦丁及葛根素抑制低密度脂蛋白(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5.0 μmol·L^-1槲皮素、芦丁及葛根素与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,相对电泳迁移率（REM）,硫代巴比妥酸反应物质（TBARS）及载脂蛋白羰基含量的动力学改变,并与对照组比较。结果：Cu²⁺介导LDL氧化修饰时,在2,4,6,8,12,24 h后,其A₂₃₄,REM,TBARS及载脂蛋白羰基含量均逐步增加；加入5.0 μmol·L^-1槲皮素、芦丁及葛根素的实验组,Cu²⁺介导LDL的氧化修饰分别延迟2～6 h,2 h和2 h,其A₂₃₄,REM,TBARS及载脂蛋白羰基含量较对照组降低；槲皮素实验组分别较对照组降低27.7%～49.6%,24.1%～38.6%,19.8%～34.3%及36.4%～56.8%；芦丁实验组分别降低12.8%～39.3%,15.7%～32.0%,19.0%～28.1%及12.8%～50.3%；葛根素实验组分别降低3.3%～19.2%,7.0%～22.5%,19.5%～22.8%及8.6%～47.0%。结论：槲皮素、芦丁及葛根素均可抑制Cu²⁺诱导的LDL的氧化修饰,且槲皮素的抗氧化作用较芦丁及葛根素强。

Inhibitory effect of quercetin, rutin and puerarin on LDL oxidation induced by Cu2+

OBJECTIVE: To evaluate the inhibitory effect of quercetin, rutin and puerarin on the LDL oxidation induced by Cu2+ and to investigate their action on the prevention and treatment of atherosclerosis. METHOD: 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. Quercetin, rutin and puerarin at 5 micromol x L(-1) 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, and the values were compared between the two groups. RESULT: (1) The values of A234, REM, TBARS and protein carbonyls formation increased gradually during LDL oxidation induced by Cu2+ in vitro. (2) During LDL oxidation induced by Cu2+ in vitro and incubation with each of quercetin, rutin and puerarin, the kinetic changes of A234, REM, TBARS and protein carbonyls formation showed lag phases of 2-6 h, 2 h and 2 h respectively, and the corresponding values for each of the agents treated group were reduced by 27.7%-49.6%, 24.1%-38.6%, 19.8%-34.3% and 36.4%-56.8%; 12.8%-39.3%, 15.7%-32.0%, 19.0%-28.1% and 12.8%-50.3%; and 3.3%-19.2%, 7.0%-22.5%, 19.5%-22.8% and 8.6%-47.0%, respectively. CONCLUSION: These results suggest that quercetin, rutin and puerarin can substantially inhibit LDL oxidation, and quercetin has antioxidation ability stronger than rutin and puerarin.