Shao Zuo-Hui, Xie Jing-Tian, Vanden Hoek Terry L, Mehendale Sangeeta, Aung Han, Li Chang-Qing, Qin Yimin, Schumacker Paul T, Becker Lance B, Yuan Chun-Su
Tang Center for Herbal Medicine Research, The Pritzker School of Medicine, The University of Chicago, IL 60637, USA.
Biochim Biophys Acta. 2004 Feb 24;1670(3):165-71. doi: 10.1016/j.bbagen.2003.12.001.
It is postulated that antioxidant properties of American ginseng root mediate its cardioprotective actions. The antioxidant capabilities of the American ginseng root have been demonstrated previously, however, the berry of the American ginseng has not yet been evaluated. In this study, we tested the American ginseng berry extract (AGBE) for its antioxidant effects in cell-free chemical systems using H(2)O(2)/FeSO(4) to generate hydroxyl radicals which were measured by a fluorescent probe, 2', 7'-dichlorofluorescin diacetate (DCFH/DA). Xanthine/xanthine oxidase was used to generate superoxide anion, which was measured by a fluorescent probe dihydroethidium (DHE). We found that AGBE decreased fluorescence significantly, suggesting that AGBE scavenges oxygen free radicals. We further tested whether AGBE (0.1-1 mg/ml) can protect cardiomyocytes from oxidative injury induced by exogenous or endogenous oxidants. Cells were exposed to either H(2)O(2) or antimycin A (a mitochondrial electron transport chain site III inhibitor that augments mitochondrial oxidant production). The resulting oxidant stress was measured using DCFH/DA and the cell death was assessed using propidium iodide staining. Pretreatment with AGBE (1 mg/ml) significantly attenuated DCF fluorescence by 49% or 85% and reduced cell death by 59% or 63% in cells exposed to H(2)O(2) or antimycin A, respectively. When the effects of extracts from berry and root of American ginseng were compared in cardiomyocytes exposed to antimycin A, we observed that AGBE conferred greater antioxidant protection at the same dose. We conclude that AGBE is a potent antioxidant that protects cardiomyocytes against oxidant-mediated injury and this protection is partly mediated by its free radical scavenging properties.
据推测，西洋参根的抗氧化特性介导了其心脏保护作用。西洋参根的抗氧化能力此前已得到证实，然而，西洋参的浆果尚未得到评估。在本研究中，我们使用H(2)O(2)/FeSO(4)在无细胞化学体系中产生羟基自由基，并通过荧光探针2',7'-二氯荧光素二乙酸酯（DCFH/DA）进行测定，测试了西洋参浆果提取物（AGBE）的抗氧化作用。使用黄嘌呤/黄嘌呤氧化酶产生超氧阴离子，并通过荧光探针二氢乙锭（DHE）进行测定。我们发现AGBE显著降低了荧光，表明AGBE可清除氧自由基。我们进一步测试了AGBE（0.1 - 1 mg/ml）是否能保护心肌细胞免受外源性或内源性氧化剂诱导的氧化损伤。细胞分别暴露于H(2)O(2)或抗霉素A（一种线粒体电子传递链位点III抑制剂，可增加线粒体氧化剂的产生）。使用DCFH/DA测量由此产生的氧化应激，并使用碘化丙啶染色评估细胞死亡情况。用AGBE（1 mg/ml）预处理可使暴露于H(2)O(2)或抗霉素A的细胞中的DCF荧光分别显著降低49%或85%，并使细胞死亡分别减少59%或63%。当在暴露于抗霉素A的心肌细胞中比较西洋参浆果和根的提取物的作用时，我们观察到在相同剂量下AGBE具有更强的抗氧化保护作用。我们得出结论，AGBE是一种有效的抗氧化剂，可保护心肌细胞免受氧化剂介导的损伤，这种保护作用部分是由其自由基清除特性介导的。
