title: Flavonoids with DNA strand-scission activity from Rhus javanica var. roxburghiana.
abstract: The flavonoids isolated from the stems of Rhus javanica var. roxburghiana, taxifolin (1), fisetin (2), fustin (3), 3,7,4'-trihydroxyflavanone (4) and 3,7,4'-trihydroxyflavone (5) caused breakage of supercoiled plasmid pBR322 DNA in the presence of Cu(II). Cu(I) was shown to be an essential intermediate by using the Cu(I)-specific sequestering reagent neocuproine. The Cu(II)-mediated DNA scissions induced by 1, 2, 3 and 5 were inhibited by the addition of catalase and exhibited DNA strand break by the addition of KI and superoxide dimutase (SOD), while in the Cu(II)-mediated DNA scissions induced by 4 was inhibited by the addition of KI, SOD, and catalase. It is concluded that 1, 2, 3, and 5 can induce H2O2 and superoxide anion, while 4 can induce OH* and H2O2 and subsequent oxidative damage of DNA in the presence of Cu(II).
authors.affiliation: School of Pharmacy, Kaohsiung Medical University, Kaohsiung 807, Taiwan. lincna@cc.kmu.edu.tw
authors.forename: Chun-Nan
authors.initials: CN
authors.lastname: Lin
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Chen
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Yen
mesh_terms: D003300:Copper / Q000009:adverse effects; D004249:DNA Damage; D004278:DNA, Superhelical / Q000187:drug effects*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D015394:Molecular Structure; D009153:Mutagens / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D018547:Plant Stems; D017382:Reactive Oxygen Species; D029045:Rhus / Q000737:chemistry*
chemical_list: D004278:DNA, Superhelical; D005419:Flavonoids; D009153:Mutagens; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D003300:Copper