中文摘要：

采用荭草素和异荭草素标准品,通过测定两者对DPPH·、ABTS＋·、H2O2、·OH自由基的清除率,脂质过氧化,Cu2＋/H2O2诱导的牛血清蛋白（BSA）和DNA氧化损伤及BSA蛋白羰基化的抑制作用来评价二者的抗氧化活性,另外用MTT法评价了二者对人肝癌（HepG2）细胞生长的影响.结果表明,荭草素和异荭草素均可清除自由基,抑制脂质过氧化、BSA和DNA氧化损伤和BSA羰基化,且一定浓度范围内异荭草素的抗氧化活性强于荭草素;另外荭草素和异荭草素可显著抑制HepG2细胞增殖,并呈浓度和时间依赖性,且异荭草素的抑制率高于荭草素,说明异荭草素是优于荭草素的有抗癌功效的天然抗氧化剂.

英文摘要：

In this study, the effects of orientin and isoorientin on radical-scavenging activities （DPPH·, ABTS ＋ , H202, · OH）, lipid peroxidation, Cu2＋/H202 induced BSA and DNA oxidative damage, and BSA protein carbonyls were investigated. The results showed that orientin and isoorientin exhibited high radical-scavenging activities and also effectively protected biological macromolecules including proteins, lipids, and DNA against oxidative damage induced by Cu2＋/H202. Moreover, the MTT assay revealed that orientin and isoorientin inhibited proliferation of HepG2 cells in a dose and time dependent manner, and the antioxidant and anticancer activities of isoorientin was much better than that of orientin. These re- suits demonstrate the remarkable potentiality of isoorientin as a valuable nature antioxidant possessing o- riginal anticancer abilities.