Cheng Hong-Ming, Qiu Ying-Kun, Wu Zhen, Zhao Yu-Fen
Department of Chemistry and Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China.
J Asian Nat Prod Res. 2011 Jan;13(1):12-9. doi: 10.1080/10286020.2010.537262.
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.
紫草素（β - 紫红素）是一种萘并二蒽酮衍生物，已显示出多种能力，如抗炎、抗肿瘤、细胞毒性和抗菌活性。在铜（II）存在的情况下，紫草素会导致超螺旋质粒pBR322 DNA断裂。所测试的其他金属离子[镁（II）、钙（II）和镍（II）]均无效，只有铁（II）在DNA断裂反应中具有相同的能力。超氧化物歧化酶、过氧化氢酶、硫脲、叠氮化钠、碘化钾和苯甲酸钠对DNA断裂的抑制作用证实了活性氧参与了该反应。使用铜（I）特异性螯合剂新铜试剂表明铜（I）是必不可少的中间体。紫草素诱导的HeLa细胞凋亡涉及细胞内活性氧（ROS）增加的机制。有人提出，紫草素在铜（II）存在下作为促氧化剂产生活性氧，而活性氧导致细胞中的DNA损伤和凋亡性细胞死亡。
