Redox regulation of tumor cell toxicity by flavones from Lethedon tannaensis
Redox regulation of tumor cell toxicity by flavones from Lethedon tannaensis
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DOI：
10.1016/s0891-5849(99)00039-8
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发表时间：
1999-07-01
影响因子：
7.4
通讯作者：
Land, EJ
中科院分区：
文献类型：
--
作者：
Bensasson, RV;Jossang, A;Land, EJ
本工作的目的是寻求潜在预测值的相关性，证明7种5-羟基-7-甲氧基黄酮以及两种糖苷衍生物对人鼻咽癌（KB）细胞的细胞毒性的氧化还原控制，所有这些都是从Lethedon tannaensis中提取的。在这种方法中，氧化还原控制的特征在于定量表达黄酮的相对供电子能力的物理化学参数，该参数是单线态氧O-2猝灭的二级速率常数k（Δ）（（1）Δ g）。该速率常数k（Delta）通常与给定分子D提供电子的能力相关，因此与电对的还原电势E（D.+/-）相关。D）。结果表明，黄酮的毒性与其易氧化性呈线性关系：与单线态氧反应的速率常数越大，越易氧化，还原电位（D.+/-）越负或越负。D），细胞毒性越高。这些结果提示了新的筛选策略，以识别和改进潜在的抗肿瘤药物。(C)1999 Elsevier Science Inc.
The purpose of the present work has been to seek a correlation of potential predictive value, demonstrating redox control of cytotoxicity toward human nasopharynx carcinoma (KB) cells by seven 5-hydroxy-7-methoxyflavones, together with two glycoside derivatives, all extracted from Lethedon tannaensis, In this approach, redox control is characterized by a physicochemical parameter expressing quantitatively the relative electron-donating power of the flavones, this parameter being the second order rate constant, k(Delta), for quenching of singlet oxygen O-2 ((1)Delta g). This rate constant k(Delta) is usually related to the ability of a given molecule D to donate an electron and, thus, with the reduction potential E of the couple (D.+/D). Our results show that the flavone toxicity is linearly correlated with ease of oxidation: the higher the rate constant of reaction with singlet oxygen, the easier the oxidation, the less positive or more negative the reduction potential (D.+/D), the higher the cytotoxicity. The results suggest new screening strategies to identify and improve potential antitumor drugs. (C) 1999 Elsevier Science Inc.