Marczylo T H, Hayatsu T, Arimoto-Kobayashi S, Tada M, Fujita K, Kamataki T, Nakayama K, Hayatsu H
Faculty of Pharmaceutical Sciences, Okayama University, Tsushima-naka 1-1-1, Okayama, Japan.
Mutat Res. 1999 Aug 18;444(2):451-61. doi: 10.1016/s1383-5718(99)00109-6.
Purpurin (1,2,4-trihydroxy-9,10-anthraquinone) is a naturally occurring anthraquinone pigment found in species of madder root. We have found that the presence of purpurin in bacterial mutagenicity assays is responsible for a marked inhibition of mutagenicity induced by food-derived heterocyclic amines. Purpurin was found to be a better inhibitor of Trp-P-2-dependent mutagenicity than either epigallocatechin gallate or chlorophyllin both of which are well-established anti-mutagenic components of diet. Inhibition of Trp-P-2(NHOH) mutagenicity by purpurin was dependent upon pH. It was a better inhibitor in neutral than acidic conditions. Purpurin was protective against the direct mutagen Trp-P-2(NHOH) in both the presence and the absence of hepatic S9 but required pre-incubation. Finally, purpurin was responsible for the inhibition of human CYP1A2 and human NADPH-cytochrome P450 reductase and a decrease in the bioactivation of Trp-P-2 by these enzymes when they were expressed in Salmonella typhimurium TA1538ARO. However, inhibition of Trp-P-2(NHOH)-dependent mutations suggests purpurin also has a direct effect on this mutagen in addition to inhibiting its formation by CYP1A2.
紫红素（1,2,4-三羟基-9,10-蒽醌）是一种天然存在的蒽醌色素，存在于茜草科植物的根中。我们发现，在细菌致突变性试验中，紫红素的存在可显著抑制食物来源的杂环胺诱导的致突变性。与表没食子儿茶素没食子酸酯或叶绿酸相比，紫红素是色氨酸-P-2依赖性致突变性的更好抑制剂，而这两种物质都是已确定的饮食抗诱变成分。紫红素对色氨酸-P-2（NHOH）致突变性的抑制作用取决于pH值。在中性条件下它比在酸性条件下是更好的抑制剂。无论有无肝S9，紫红素对直接诱变剂色氨酸-P-2（NHOH）都有保护作用，但需要预孵育。最后，当在鼠伤寒沙门氏菌TA1538aro中表达时，紫红素可抑制人CYP1A2和人NADPH-细胞色素P450还原酶，并降低这些酶对色氨酸-P-2的生物活化作用。然而，对色氨酸-P-2（NHOH）依赖性突变作用的抑制表明，紫红素除了抑制其通过CYP1A2形成外，对这种诱变剂也有直接作用。
