黄芩总黄酮对低密度脂蛋白氧化的抑制作用

Inhibitory Effect of Flavonoids Extracts of Scutellaria Baicalensis on Low Density Lipoprotein Oxidation

目的:从单味中药黄芩中提取总黄酮类化合物,观察其对低密度脂蛋白(LDL)氧化修饰的抑制作用。方法:以75%乙醇提取并加用碱提取酸沉淀法提取黄酮类成分,观察其对 Cu^(2+)诱导的 LDL 氧化的抑制作用,以硫代巴比妥酸反应物质法(TBARS)测定丙二醛(MDA)含量并计算药物对氧化的抑制率。利用直线相关及线性回归分析抑制率与药物浓度的关系。结果:黄芩总黄酮类提取物可使氧化动力曲线迟滞相延长,曲线峰值降低,40 μg/ml 时明显抑制过氧化脂质生成并有浓度依赖性,抑制率为50%时所需浓度(IR_(50))为12.88 μg/ml。结论:黄芩总黄酮类提取物有抑制 DL 体外氧化作用,并有浓度依赖性。

Objective:To observe the inhibitory effect of extracted flavonoids of Scutellaria baiealensis (SB) on low density lipoprotein (LDL) oxidation.Methods:Flavonoids mixture extracted with 75% ethanol was solved in alkaline solution and then precipitated with acid solu- tion.LDL oxidation was initiated by incubation with CuCl_2 at 37℃.Before and after incubation,oxidation was assessed by determining the thiobarbituric acid reactive substances (TBARS),which was also used to measure the content of malondialdehyde (MDA).The re- lation between the inhibitory rate and extract concentration was assayed by bivariate correlation and linear regression.Result:The flavonoid extracts of SB could prolong the retard phase in kinetic process and lower the peak value of curve,obviously inhibit the perox- idative products formation.LDL oxidation was significantly suppressed by 40 μg/ml extracts.Conclusion:The flavonoids extracts of SB play an important role in oxidative inhibition of LDL in vivo,and the effect was in a concentration-dependent manner.