Janzowski C, Glaab V, Mueller C, Straesser U, Kamp H G, Eisenbrand G
Department of Chemistry, Division of Food Chemistry and Environmental Toxicology, University of Kaiserlautern, 67663 Kaiserslautern, Germany.
Mutagenesis. 2003 Sep;18(5):465-70. doi: 10.1093/mutage/geg018.
Alpha,beta-unsaturated carbonyl compounds occur in food and other environmental media. Due to their reactivity with cellular nucleophiles (e.g. Michael adduct formation with DNA bases and with glutathione) they might represent a potential health risk. In this study, induction of oxidative DNA damage was investigated in mammalian cells, as a consequence of glutathione depletion induced by selected food relevant 2-alkenals, including E-(2)-hexenal (HEX), (2E,4E)-2,4-hexadienal (HEXDI) and (E)-2-cinnamaldehyde (CA) and the cyclic analogue 2-cyclohexen-1-one (CHX). Oxidative DNA breakage was monitored with the Comet assay, using treatment with formamidopyrimidine-DNA glycosylase (FPG). Total cellular glutathione (tGSH) was determined in a kinetic, photometric assay. After 1 h incubation of V79 cells with HEX (100 microM) and CHX (300 microM), HEXDI and CA (300 microM each), tGSH was depleted down to <20% of control (viability >85%). Under these conditions, FPG-sensitive sites were not observed; moderate direct DNA breakage, however, was detectable. During 3 h post-incubation (without test compound) distinct oxidative DNA breakage occurred in HEX- and CA-, but not in CHX- and HEXDI-pretreated cells. Direct DNA breakage was markedly diminished, most probably by repair processes, and tGSH concentrations were observed to increase again within 3 h post-treatment. The results give strong evidence for alkenal-mediated oxidative stress contributing to cytotoxic/genotoxic cell damage. The extent of oxidative stress appears to be influenced by structure-specific properties of the alkenals.
α,β-不饱和羰基化合物存在于食品和其他环境介质中。由于它们能与细胞亲核试剂发生反应（例如与DNA碱基和谷胱甘肽形成迈克尔加成物），它们可能存在潜在的健康风险。在本研究中，研究了哺乳动物细胞中氧化DNA损伤的诱导情况，这是由选定的与食品相关的2-烯醛（包括E-(2)-己烯醛（HEX）、(2E,4E)-2,4-己二烯醛（HEXDI）和(E)-2-肉桂醛（CA））以及环状类似物2-环己烯-1-酮（CHX）诱导的谷胱甘肽耗竭所致。使用甲酰胺嘧啶-DNA糖基化酶（FPG）处理，通过彗星试验监测氧化DNA断裂情况。通过动力学光度法测定总细胞谷胱甘肽（tGSH）。用HEX（100 microM）和CHX（300 microM）、HEXDI和CA（各300 microM）孵育V79细胞1小时后，tGSH耗竭至对照的<20%（活力>85%）。在这些条件下，未观察到FPG敏感位点；然而，可检测到中度的直接DNA断裂。在孵育后3小时（无测试化合物）期间，HEX和CA预处理的细胞中发生了明显的氧化DNA断裂，而CHX和HEXDI预处理的细胞中未发生。直接DNA断裂明显减少，很可能是由于修复过程，并且在处理后3小时内观察到tGSH浓度再次升高。结果有力地证明了烯醛介导的氧化应激导致细胞毒性/遗传毒性细胞损伤。氧化应激的程度似乎受烯醛结构特异性性质的影响。
