title: Induction of apoptosis by three marine algae through generation of reactive oxygen species in human leukemic cell lines.
abstract: In this study, we examined the antitumor effect of marine algae extracts on human hepatoma and leukemia cells. Ethyl acetate extracts from Colpomenia sinuosa (Cs-EA), Halimeda discoidae (Hd-EA), and Galaxaura oblongata (Go-EA) directly inhibited the growth of human hepatoma HuH-7 cells and leukemia U937 and HL-60 cells in a time- and dose-dependent manner. Specifically, these algae extracts induced apoptosis of U937 and HL-60 cells as evaluated by detection of hypodiploid cells using flow cytometry and observation of condensed and fragmented nuclei in algae extract-treated cells. Intracellular reactive oxygen species (ROS), especially hydrogen peroxide and superoxide anion, were increased about 2-3-fold in U937 cells treated with Cs-EA for 3-5 h. Interestingly, antioxidant N-acetylcysteine effectively blocked Cs-EA-, Hd-EA-, and Go-EA-induced apoptosis, suggesting that ROS is a key mediator in the apoptotic signaling pathway. In conclusion, our results show that algae extracts induce apoptosis in human leukemia cells through generation of ROS.
authors.affiliation: Department of Medical Research and of Radiation Oncology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Huey-Lan
authors.initials: HL
authors.lastname: Huang
authors.forename: Shwu-Li
authors.initials: SL
authors.lastname: Wu
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Liao
authors.forename: Chii-Ming
authors.initials: CM
authors.lastname: Jiang
authors.forename: Ray-Ling
authors.initials: RL
authors.lastname: Huang
authors.forename: Yu-Yawn
authors.initials: YY
authors.lastname: Chen
authors.forename: Yuh-Cheng
authors.initials: YC
authors.lastname: Yang
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular; D000460:Chlorophyta / Q000378:metabolism; D056890:Eukaryota / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D007951:Leukemia, Myeloid; D008113:Liver Neoplasms; D000459:Phaeophyceae / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism* / Q000494:pharmacology*; D000461:Rhodophyta / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D017382:Reactive Oxygen Species