Powerful and prolonged protection of human retinal pigment epithelial cells, keratinocytes, and mouse leukemia cells against oxidative damage: The indirect antioxidant effects of sulforaphane
Powerful and prolonged protection of human retinal pigment epithelial cells, keratinocytes, and mouse leukemia cells against oxidative damage: The indirect antioxidant effects of sulforaphane
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DOI：
10.1073/pnas.261572998
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发表时间：
2001-12-18
影响因子：
11.1
通讯作者：
Talalay, P
中科院分区：
文献类型：
--
作者：
Gao, XQ;Dinkova-Kostova, AT;Talalay, P
哺乳动物细胞配备有精心设计的系统，用于保护免受活性氧和氮物质和亲电体的毒性，这些物质对其DNA的完整性构成持续的危险。2相酶（例如，谷胱甘肽转移酶，NAD（P）H：醌还原酶）和谷胱甘肽合成被广泛认为对亲电子致癌物起主要的保护作用，但它们的抗氧化功能引起的关注要少得多。通过测量细胞死亡的浓度依赖性来量化四种氧化应激物（甲萘醌、叔丁基过氧化氢、4-羟基壬烯醛和过氧亚硝酸盐）对人成人视网膜色素上皮细胞（ARPE-19）的细胞毒性，并表示为每种氧化剂的中位效应剂量（D-m）。在用0-5 μ M浓度的萝卜硫素（从花椰菜中分离的强大的2相酶诱导剂）处理ARPE-19细胞24小时后，氧化剂的毒性显著降低，如D-m值增加1.5- 3倍所示。保护的程度是氧化剂的性质以及氧化剂和萝卜硫素两者的浓度的函数。去除萝卜硫素后，保护作用延长并持续几天，然后恢复到对照水平。萝卜硫素依赖性增加的细胞溶质醌还原酶的比活性和谷胱甘肽水平与保护程度的D-m值测量的高度显着相关。抗氧化保护也证明了人类HaCaT角质形成细胞和L1210小鼠白血病细胞。因此，萝卜硫素提供的多方面且长期的抗氧化保护很可能是一种普遍现象，通过诱导第二阶段酶反应来介导。
Mammalian cells are equipped with elaborate systems for protection against the toxicity of reactive oxygen and nitrogen species and electrophiles that are constant dangers to the integrity of their DNA. Phase 2 enzymes (e.g., glutathione transferases, NAD(P)H:quinone reductase) and glutathione synthesis are widely recognized as playing major protective roles against electrophilic carcinogens, but their antioxidant functions have attracted far less attention. The cytotoxicities of four oxidative stressors (menadione, tert-butyl hydroperoxide, 4-hydroxynonenal, and peroxynitrite) for human adult retinal pigment epithelial cells (ARPE-19) were quantified by measuring the concentration dependence of cell death and were expressed as the median effect dose (D-m) for each oxidant. After treatment of ARPE-19 cells for 24 h with 0-5 muM concentrations of sulforaphane (the powerful Phase 2 enzyme inducer isolated from broccoli), the toxicities of the oxidants were markedly reduced as shown by 1.5- to 3-fold increases in D-m values. The magnitude of protection was a function of the nature of the oxidants and the concentrations of both the oxidants and sulforaphane. Protection was prolonged and persisted for several days after removal of sulforaphane before returning to control levels. The sulforaphane-dependent increases in specific activities of cytosolic quinone reductase and the glutathione levels were highly significantly correlated with the degree of protection as measured by D-m values. Antioxidant protection was also demonstrated for human HaCaT keratinocytes and L1210 murine leukemia cells. It is therefore highly likely that the multifaceted and prolonged antioxidant protection provided by sulforaphane is a general phenomenon that is mediated through induction of the Phase 2 enzyme response.