da Costa Medina Luis Fernando, Viau Cassiana Macagnan, Moura Dinara Jaqueline, Saffi Jenifer, Stefani Valter, Brandelli Adriano, Henriques João Antonio Pêgas
Laboratório de Genotoxicidade-Instituto Royal-Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
Mutat Res. 2008 Feb 29;650(2):140-9. doi: 10.1016/j.mrgentox.2007.11.003. Epub 2007 Nov 22.
There are few studies on the biological activity of aminohydroxy derivates of 1,4-naphthoquinone (1,4-NQ) on prokaryotic and eukaryotic cells. We determined the mutagenic activity of 5-amino-8-hydroxy-1,4-naphthoquinone (ANQ) and 5-amino-2,8-dihydroxy-1,4-naphthoquinone (ANQ-OH) as compared to the unsubstituted 1,4-NQ in Salmonella/microsome assay. Potential mutagenic and recombinogenic effects and cytotoxicity were analyzed in haploid and diploid cultures of the yeast Saccharomyces cerevisiae. In Salmonella/microsome assay, 1,4-NQ was not mutagenic, whereas aminohydroxynaphthoquinones were weakly mutagenic in TA98 and TA102 strains. In haploid yeast in stationary growth phase (STAT), mutagenic response was only observed for the hom3 locus at the highest dose. In diploid yeast, aminohydroxynaphthoquinones did not induce any recombinogenic events, but 1,4-NQ was shown to be a recombinogenic agent. These results suggest that aminohydroxynaphthoquinones are weak mutagenic agents only in prokaryotic cells. The cytotoxicity of 1,4-NQ in yeast stationary cells was more significant in diploid cells as compared to that observed in haploid cells. However, ANQ and ANQOH were slightly cytotoxic in all treatments. Genotoxicity of these naphthoquinone compounds was also determined in V79 Chinese hamster lung fibroblast cells using standard Comet, as well as modified Comet assay with the bacterial enzymes formamidopyrimidine DNA-glycosylase (FPG) and endonuclease III (ENDOIII). Both 1,4-NQ and ANQ induced pronounced DNA damage in the standard Comet assay. The genotoxic effect of ANQ-OH was observed only at the highest dose. In presence of metabolic activation all substances showed genotoxic effects on V79 cells. Post-treatment of V79 cells with ENDOIII and FPG proteins did not have a significant effect on ANQ-OH-induced oxidative DNA damage as compared to standard alkaline Comet assay. However, all naphthoquinones were genotoxic in V79 cells in the presence of metabolic activation and post-treatment with enzymes, indicating that all compounds induced oxidative DNA damage in V79 cells. Our data suggest that aminohydroxynaphthoquinone pro-oxidant activity, together with their capability of DNA intercalation, have an important role in mutagenic and genotoxic activities.
关于1,4 - 萘醌（1,4 - NQ）的氨基羟基衍生物对原核细胞和真核细胞的生物活性研究较少。我们在沙门氏菌/微粒体试验中，测定了5 - 氨基 - 8 - 羟基 - 1,4 - 萘醌（ANQ）和5 - 氨基 - 2,8 - 二羟基 - 1,4 - 萘醌（ANQ - OH）与未取代的1,4 - NQ相比的致突变活性。在酿酒酵母的单倍体和二倍体培养物中分析了潜在的致突变和重组效应以及细胞毒性。在沙门氏菌/微粒体试验中，1,4 - NQ不具有致突变性，而氨基羟基萘醌在TA98和TA102菌株中具有弱致突变性。在处于稳定生长期（STAT）的单倍体酵母中，仅在最高剂量下观察到对hom3基因座的致突变反应。在二倍体酵母中，氨基羟基萘醌未诱导任何重组事件，但1,4 - NQ被证明是一种重组剂。这些结果表明，氨基羟基萘醌仅在原核细胞中是弱致突变剂。与单倍体细胞相比，1,4 - NQ在酵母静止细胞中的细胞毒性在二倍体细胞中更显著。然而，ANQ和ANQOH在所有处理中均有轻微细胞毒性。还使用标准彗星试验以及用细菌酶甲酰胺嘧啶DNA - 糖基化酶（FPG）和内切酶III（ENDOIII）进行改良的彗星试验，在V79中国仓鼠肺成纤维细胞中测定了这些萘醌化合物的遗传毒性。在标准彗星试验中，1,4 - NQ和ANQ均诱导了明显的DNA损伤。仅在最高剂量下观察到ANQ - OH的遗传毒性作用。在代谢活化存在的情况下，所有物质均对V79细胞显示出遗传毒性作用。与标准碱性彗星试验相比，用ENDOIII和FPG蛋白对V79细胞进行后处理对ANQ - OH诱导的氧化性DNA损伤没有显著影响。然而，在代谢活化存在且用酶进行后处理的情况下，所有萘醌在V79细胞中均具有遗传毒性，表明所有化合物均在V79细胞中诱导了氧化性DNA损伤。我们的数据表明，氨基羟基萘醌的促氧化活性及其DNA嵌入能力在致突变和遗传毒性活性中起重要作用。
