荭草苷和牡荆苷对H_2O_2氧化损伤人红细胞的保护作用

Protective Effects of Orientin and Vitexin on H_2O_2-Induced Oxidative Stress in Human Erythrocytes

目的:探讨荭草苷和牡荆苷对人红细胞氧化损伤的保护作用及其构效关系。方法:建立过氧化氢(hydrogen peroxide,H_2O_2)氧化损伤人红细胞的模型,实验随机分为正常组,H_2O_2氧化损伤组,荭草苷和牡荆苷(终浓度10、20、40μg·mL^(-1))不同剂量组,20μg·mL^(-1)维生素C(vitamin C,VC)阳性对照组。研究比较荭草苷和牡荆苷各剂量组对1,1-二苯基-2-苦肼基(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基的清除率、氧化损伤红细胞的溶血率、活性氧(reactive oxygen species,ROS)、抗氧化酶系及ATP酶活性、丙二醛(malonaldehyde,MDA)、高铁血红蛋白(methemoglobin,Met Hb)及巯基(sulfhydryl,-SH)含量的影响,扫描电镜观察红细胞表面形态。结果:荭草苷和牡荆苷对DPPH自由基都具有一定的清除能力,均能有效降低红细胞溶血率,减少ROS、MDA及Met Hb含量,均能不同程度保护抗氧化酶、ATP酶活性及增加-SH含量(P<0.05),显著改善红细胞膜的形态,其中10μg·mL^(-1)和20μg·mL^(-1)的荭草苷的作用效果优于相同剂量的牡荆苷,而40μg·mL^(-1)的荭草苷和牡荆苷对红细胞具有相同的保护作用,且与VC作用相当。结论:荭草苷和牡荆苷对H_2O_2致氧化损伤的人红细胞具有保护作用,可能是通过对抗氧自由基,抑制脂质过氧化,保护细胞内抗氧化酶活性和细胞膜蛋白上的-SH来实现的,且荭草苷的保护作用效果优于牡荆苷。

Objective：This study investigated the protective effects of orientin and vitexin on hydrogen peroxide （H2O2 ）-induced oxidative stress in human erythrocytes and structure-activity relationship. Methods：Oxidative stress model induced by H2O2 was established in this study. The experiment was randomly divided into normal group,H2O2 group （oxidative stress group）,20 μg·mL^ -1 of VC group as a positive control,10,20 and 40 μg·mL -1 of Orientin groups and Vitexin groups,respectively. Erythrocyte suspension was incubated with different concentrations of orientin and vitexin,and then 1,1-diphenyl-2-picrylhydrazyl （DPPH） radical-scavenging ability,hemolysis rate,reactive oxygen species （ROS）,antioxidant and ATP enzymes,malonaldehyde （MDA）,methemoglobin （MetHb） and sulfhydryl （-SH） content were evaluated by different methods. Erythrocyte morphology was also observed with scanning electron microscope. Results：Erythrocytes pre-treated orientin or vitexin had certain DPPH-radical clearance ability,lowered hemolysis rates,reduced the content of ROS,MDA,MetHb protected antioxidative enzymes and ATPs activities and increased thiol group content in a dose-dependent manner （P〈0.05）. Moreover,orientin and vitexin recovered cell surface morphogy. Comparative results showed the bio-activity of orientin was same as vitexin when the concentration was 40 μg·mL ^-1 for both,which was equivalent to VC at 20 μg·mL ^-1 . But orientin showed better biological activity than vitexin at the concentrations of 10 and 20 μg·mL ^-1 . Conclusion：Orientin and vitexin are able to protect human erythrocytes from oxidative stress through scavenging oxygen free radicals,inhibiting the perioxidation of lipids,protecting anti-oxidative and ATP enzymes activities and increasing-SH content. Moreover,the protective effects of orientin showed better biological activity than vitexin.