Oxidation of eugenol to form DNA adducts and 8-hydroxy-2′-deoxyguanosine:: Role of quinone methide derivative in DNA adduct formation
Oxidation of eugenol to form DNA adducts and 8-hydroxy-2′-deoxyguanosine:: Role of quinone methide derivative in DNA adduct formation
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DOI：
10.1093/carcin/19.3.437
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发表时间：
1998-03-01
期刊：
影响因子：
4.7
通讯作者：
Pongracz, K
中科院分区：
文献类型：
--
作者：
Bodell, WJ;Ye, QP;Pongracz, K
我们研究了丁香酚形成DNA加合物和氧化碱基损伤的活化作用。用丁香酚处理含有髓过氧化物酶的HL-60细胞，产生了剂量依赖性的三种DNA加合物的形成，如用P1增强的P-32后标记所检测到的。HL-60细胞与100 μ M丁香酚和100 μ M H2 O2的组合孵育使HL-60细胞中DNA加合物的水平增强14倍，这表明加合物形成中的过氧化物酶活化。在体外激活丁香酚与辣根过氧化物酶或髓过氧化物酶和H2 O2产生三个DNA加合物，抑制通过添加抗坏血酸或谷胱甘肽，分别由66%和90%，。丁香酚处理HL-60细胞后形成的DNA加合物与体外过氧化物酶激活形成的DNA加合物相同。除了加合物的形成，丁香酚的过氧化物酶活化产生了2- 3倍的氧化性碱损伤水平的增加，丁香酚醌甲基化通过Ag（I）氧化丁香酚制备。丁香酚的过氧化物酶活化得到具有与丁香酚醌甲基化物相同的UV光谱的产物，这表明它是产物之一。丁子香酚醌甲基化物与DNA或脱氧鸟苷-3 '-磷酸反应产生两种主要加合物（2和4）。将丁子香酚醌甲基化物与脱氧鸟苷-3 '-磷酸孵育形成的DNA加合物2与用丁子香酚处理的HL-60细胞中形成的DNA 2加合物进行比较，结果表明它们是相同的。这表明丁香酚醌甲基化物是导致细胞中DNA加合物形成的反应性中间体之一。用10 μ M硫酸铜活化丁香酚，产生一种主要加合物（2）和几种次要加合物。通过用硫酸铜活化丁香酚形成的DNA加合物2与通过丁香酚的过氧化物酶活化或通过与丁香酚醌甲基化物反应形成的DNA加合物2相同，这表明由这些活化系统产生的反应性中间体是相似的。硫酸铜使氧化性碱损伤水平增加95倍，而加入浴铜灵二磺酸或过氧化氢酶可显著抑制氧化性碱损伤水平。氧化性碱损伤的形成与芬顿反应机理一致。我们的研究结果表明，丁香酚可以被激活，形成DNA加合物和氧化碱基损伤。我们认为，这种DNA损伤的形成可能有助于观察到的丁香酚的毒性。
We have investigated the activation of eugenol to form DNA adducts and oxidative base damage. Treatment of myeloperoxidase containing HL-60 cells with eugenol, produced a dose-dependent formation of three DNA adducts as detected with P1-enhanced P-32-post-labeling. Incubation of HL-60 cells with the combination of 100 mu M eugenol and 100 mu M H2O2 potentiated the levels of DNA adduct in HL-60 cells by 14-fold, which suggests peroxidase activation in adduct formation. In vitro activation of eugenol with either horseradish peroxidase or myeloperoxidase and H2O2 produced three DNA adducts that were inhibited by the addition of either ascorbic acid or glutathione, by 66 and 90%, respectively. The DNA adducts formed in HL-60 cells treated with eugenol were the same as those formed by in vitro peroxidase activation. In addition to adduct formation, peroxidase activation of eugenol produced a 2- to 3-fold increase in the level of oxidative base damage, Eugenol quinone methide was prepared by Ag(I)oxide oxidation of eugenol. Peroxidase activation of eugenol gave a product that had the same UV spectrum as eugenol quinone methide, which suggests that it was one of the products. Reaction of eugenol quinone methide with either DNA or deoxyguanosine-3'-phosphate produced two principal adducts (2 and 4). When DNA adduct 2 formed by incubation of eugenol quinone methide with deoxyguanosine-3'-phosphate was compared with DNA 2 adduct formed in HL-60 cells treated with eugenol results demonstrated that they were the same. This suggests that eugenol quinone methide is one of the reactive intermediates leading to DNA adduct formation in cells. Activation of eugenol with 10 mu M copper sulfate resulted in the production of one principal (2) and several minor adducts. DNA adduct 2 formed by activation of eugenol with copper sulfate was the same as DNA adduct 2 formed by either peroxidase activation of eugenol or by reactions with eugenol quinone methide, which indicates that the reactive intermediates generated by these activation systems were similar. Copper sulfate produced a 95-fold increase in the level of oxidative base damage, which was significantly inhibited by the addition of either bathocuproinedisulphonic acid or catalase. The formation of oxidative base damage was consistent with a Fenton reaction mechanism. Our results demonstrate that eugenol can be activated to form both DNA adducts and oxidative base damage. We propose that the formation of this DNA damage may contribute to the observed toxic properties of eugenol.