Detection of DNA Adducts Originating from 1-Methoxy-3-indolylmethyl Glucosinolate Using Isotope-Dilution UPLC-ESI-MS/MS

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• 作者：Fabian Schumacher ; Wolfram Engst ; Bernhard H. Monien ; Simone Florian ; Anke Schnapper ; Lisa Steinhauser ; Klaus Albert ; Heinz Frank ; Albrecht Seidel ; Hansruedi Glatt
• 刊名：Analytical Chemistry
• 出版年：2012
• 出版时间：July 17, 2012
• 年：2012
• 卷：84
• 期：14
• 页码：6256-6262
• 全文大小：296K
• 年卷期：v.84,no.14(July 17, 2012)
• ISSN：1520-6882

文摘

1-Methoxy-3-indolylmethyl (1-MIM) glucosinolate, present at substantial levels in several food crops (e.g., broccoli and cabbage), forms DNA adducts in vitro and is mutagenic to bacterial and mammalian cells after activation by the plant enzyme myrosinase. Moreover, a breakdown product, 1-MIM alcohol, is metabolized to a secondary reactive intermediate by some mammalian sulfotransferases (SULTs). First, we incubated herring-sperm DNA with 1-MIM glucosinolate in the presence of myrosinase. We identified and synthesized the predominant adducts, N²-(1-MIM)-dG and N⁶-(1-MIM)-dA, and developed an UPLC-ESI-MS/MS method for their specific detection using isotopic dilution. Second, we demonstrated both DNA adducts in target cells (Salmonella typhimurium TA100 and Chinese hamster V79) of standard mutagenicity tests treated with 1-MIM glucosinolate/myrosinase as well as in 1-MIM alcohol-treated Salmonella and V79 cells engineered for expression of human SULT1A1. Similar excesses of N²-(1-MIM)-dG over N⁶-(1-MIM)-dA adducts were found in all cellular models independent of the test compound (1-MIM glucosinolate or alcohol), whereas dA adducts predominated in the cell-free system. Finally, we detected both DNA adducts in colon tissue of a mouse orally treated with 1-MIM glucosinolate. We are going to use this specific and sensitive method for investigating genotoxic risks of food-borne exposure to 1-MIM glucosinolate in animal and human studies.