Induction of apoptosis by three marine algae through generation of reactive oxygen species in human leukemic cell lines.
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.
Huang
Huey-Lan
HL
Department of Medical Research and of Radiation Oncology, Mackay Memorial Hospital, Taipei, Taiwan.
Wu
Shwu-Li
SL
Liao
Hui-Fen
HF
Jiang
Chii-Ming
CM
Huang
Ray-Ling
RL
Chen
Yu-Yawn
YY
Yang
Yuh-Cheng
YC
Chen
Yu-Jen
YJ
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
D017382:Reactive Oxygen Species