DNA damage induced by shikonin in the presence of Cu(II) ions: potential mechanism of its activity to apoptotic cell death.
Shikonin (β-alkannin), a naphthazarin derivative, has shown a variety of abilities such as anti-inflammatory, antitumoral, cytotoxic, and antimicrobial activities. In the presence of Cu(II), shikonin caused breakage of supercoiled plasmid pBR322 DNA. Other metal ions tested [Mg(II), Ca(II), and Ni(II)] were ineffective and only Fe(II) has the same ability in the DNA breakage reaction. The involvement of active oxygen in the reaction was established by the inhibition of DNA breakage by superoxide dismutase, catalase, thiourea, sodium azide, potassium iodide, and sodium benzoate. Cu(I) was shown to be an essential intermediate using the Cu(I)-specific sequestering reagent neocuproine. Shikonin induced HeLa cell apoptosis involved in the mechanism of increasing intracellular reactive oxygen species (ROS). It was suggested that shikonin generated ROS as a pro-oxidant in the presence of Cu(II), and ROS resulted in DNA damage and apoptotic cell death in cells.
Department of Chemistry and Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
Hong-Ming
HM
Cheng
Ying-Kun
YK
Qiu
Zhen
Z
Wu
Yu-Fen
YF
Zhao
D017209:Apoptosis / Q000187:drug effects*; D003300:Copper / Q000494:pharmacology*; D004249:DNA Damage; D004365:Drugs, Chinese Herbal / Q000494:pharmacology / Q000633:toxicity*; D006367:HeLa Cells; D006801:Humans; D015394:Molecular Structure; D009285:Naphthoquinones / Q000494:pharmacology / Q000633:toxicity*; D010084:Oxidation-Reduction; D010957:Plasmids / Q000235:genetics; D017382:Reactive Oxygen Species / Q000633:toxicity
D004365:Drugs, Chinese Herbal; D009285:Naphthoquinones; D017382:Reactive Oxygen Species; C016101:shikonin; D003300:Copper