Contribution of oxygen radicals to DNA cleavage by quinone compounds derived from phenolic antioxidants, tert-butylhydroquinone and 2,5-di-tert-butylhydroquinone

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• 作者：Okubo ; Tomoko ; Nagai ; Fumiko ; Ushiyama ; Keiko ; Kano ; Itsu
• 关键词：DNA cleavage ; Supercoiled DNA ; 2-tert-Butyl(1 ; 4)hydroquinone ; 3-tert-Butyl-4-hydroxyanisole ; 2 ; 5-Di-tert-butyl(1 ; 4)hydroquinone ; Oxygen radicals
• 刊名：Toxicology Letters
• 出版年：1997
• 出版时间：January 15, 1997
• 年：1997
• 卷：90
• 期：1
• 页码：11-18
• 全文大小：577 K

文摘

The effects of synthetic phenolic antioxidants, tert-butylhydroquinone (TBHQ), 2,5-di-tert-butylhydroquinone (DTBHQ) and 3-tert-butyl-4-hydroxyanisole (BHA), on DNA cleavage were examined with supercoiled plasmid DNA, pUC18, in vitro. Extensive single and double strand breaks of DNA by TBHQ were observed and almost all the DNA was converted to the linear form at 10⁻² M. The cleavage was stimulated by both CuCl₂ and FeCl₂, though the effect of FeCl₂ was smaller. Metal ion chelators and some oxygen radical scavengers inhibited the cleavage. The generation of TBHQ semiquinone radical and hydroxyl radical in the presence of copper was demonstrated by ESR spectroscopy. DTBHQ also caused DNA cleavage, though its effect was much smaller than that of TBHQ. BHA had no effect in the experimental systems employed. Oxygen radicals were considered to contribute to the DNA cleavage by TBHQ and DTBHQ.