紫薯花青素体外抗氧化及对H2O2诱导HepG2细胞氧化损伤的保护作用

目的：研究紫薯花青素的体外抗氧化作用，建立H2O2诱导HepG2细胞氧化损伤模型，初步评价紫薯花青素的抗氧化应激作用。方法：紫薯干粉经过提取、纯化制得紫薯花青素干粉，分别测定紫薯花青素的总还原力、对羟自由基（·OH）、超氧阴离子自由基（O2－•）的清除能力以及对大鼠红细胞溶血的保护作用。建立H2O2诱导HepG2细胞氧化损伤模型，采用四甲基偶氮唑蓝（methyl thiazolyl tetrazolium，MTT）法检测不同质量浓度紫薯花青素对HepG2细胞氧化损伤的保护作用。结果：紫薯花青素的还原力和VC基本相当；紫薯花青素对·OH有很好的清除效果，在实验浓度范围内有明显的剂量-效应关系；随紫薯花青素浓度的升高，对O2－•的清除作用增强，呈现良好的量-效关系，单位浓度的紫薯花青素对O2－•的清除作用比2,6-二叔丁基-4-甲基苯酚（butylated hydroxytoluene，BHT）效果好。不同质量浓度的紫薯花青素均可抑制H2O2诱导的大鼠红细胞溶血，且随着紫薯花青素质量浓度的升高，大鼠红细胞的溶血度降低，呈现良好的量-效关系。H2O2诱导的HepG2细胞氧化损伤模型中，50～1 600 μg/mL的紫薯花青素均能够抑制H2O2引起的HepG2细胞凋亡，当紫薯花青素质量浓度达到800 μg/mL时，HepG2细胞存活率为（88.03±7.48）%。结论：紫薯花青素具有良好的体外抗氧化作用，并对H2O2诱导HepG2细胞氧化损伤具有明显的保护作用，研究初步揭示了紫薯花青素具有体外抗氧化作用。

Antioxidant Activities and Protective Effect of Anthocyanins from Purple Sweet Potato on HepG2 Cell Injury Induced by H2O2

Objective: To evaluate the in vitro antioxidant activities of anthocyanins extracted from purple sweet potato
and investigate the protective effect of the anthocyanins on H2O2-induced oxidative stress in HepG2 cells. Methods: The
anthocyanins were extracted and purified from the dried powder of purple sweet potato. The total reducing power, free
radical scavenging effect and red blood cell hemolysis-protecting effect of the anthocyanins were measured. Moreover,
an in vitro HepG2 cell damage model induced by H2O2 was established, and the MTT (3-(4,5-dimethylthiazol-2-yl)-
2,5-diphenyltetrazolium bromide) method was used to detect the protective effect on HepG2 cell injury of different
concentrations of the anthocyanins. Results: The anthocyanins had good in vitro antioxidant effects, possessing reducing
power similar to that of VC and potent scavenging activities hydroxyl and superoxide anion radicals in a dose-dependent
manner. The superoxide anion radical scavenging activity was higher than that of BHT at the same concentration. The
anthocyanin extract at 50–1 600 μg/mL could restrain the HepG2 cells from apoptosis caused by H2O2 and it at 800 μg/mL
yielded a survival rate of HepG2 cells of (88.03 ± 7.48) %. Conclusion: The anthocyanins from purple sweet potato possess
good in vitro antioxidant ability and obvious protective effects on HepG2 cells from oxidative stress injury induced by H2O2.