Division of Pathology, Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, Japan.
Chem Res Toxicol. 2012 May 21;25(5):1112-8. doi: 10.1021/tx300084p. Epub 2012 Apr 30.
Lucidin-3-O-primeveroside (LuP) is a component of madder color (MC), a compound which is carcinogenic in the kidney and liver of rats. Since LuP is metabolized to generate genotoxic compounds such as lucidin (Luc) and rubiadin, it is likely that these play key roles in MC carcinogenesis. In fact, after incubation of Luc with calf thymus DNA, Luc-N(2)-dG and N(6)-dA adducts were reportedly formed, possibly via the sulfotransferase metabolic pathway. However, the precise extent of formation in vivo remains uncertain. In the present study, to quantitatively determine Luc-specific DNA adducts in in vivo samples, we developed an online sample purification method using column-switching and an isotope dilution LC-ESI-MS/MS technique. The limits of quantification were 0.2 and 0.04 fmol on column for Luc-N(2)-dG and N(6)-dA adducts, respectively. Using the new analytical method, we attempted to measure adduct levels in the kidneys and livers of rats treated with 0.06, 0.3, and 1.5% LuP in the diet for one week. Luc-N(2)-dG and N(6)-dA adducts in these organs were detected at ranges from 7.97 to 51.67/10(9) dG and from1.83 to 37.10/10(9) dA, respectively. Dose-dependent increases of each adduct were observed in both organs. These quantitative data obtained with our newly developed analytical method might help to improve our understanding of MC carcinogenesis.
染料木苷-3-O-樱草糖苷（LuP）是茜草色素（MC）的成分之一，该化合物在大鼠的肾脏和肝脏中具有致癌性。由于 LuP 代谢生成致突变化合物如染料木苷（Luc）和矢车菊素，因此这些化合物很可能在 MC 致癌作用中发挥关键作用。事实上，在 Luc 与小牛胸腺 DNA 孵育后，据报道形成了 Luc-N(2)-dG 和 N(6)-dA 加合物，可能通过磺基转移酶代谢途径。然而，其在体内的确切形成程度仍不确定。在本研究中，为了定量测定体内样品中的 Luc 特异性 DNA 加合物，我们开发了一种在线样品净化方法，使用柱切换和同位素稀释 LC-ESI-MS/MS 技术。对于 Luc-N(2)-dG 和 N(6)-dA 加合物，在柱上的定量限分别为 0.2 和 0.04 fmol。使用新的分析方法，我们尝试测量了在饮食中摄入 0.06%、0.3%和 1.5% LuP 的大鼠的肾脏和肝脏中的加合物水平，持续一周。在这些器官中检测到 Luc-N(2)-dG 和 N(6)-dA 加合物的范围分别为 7.97 至 51.67/10(9) dG 和 1.83 至 37.10/10(9) dA。在两个器官中均观察到每个加合物的剂量依赖性增加。通过我们新开发的分析方法获得的这些定量数据可能有助于提高我们对 MC 致癌作用的理解。
