Fucoxanthin induces apoptosis and enhances the antiproliferative effect of the PPARgamma ligand, troglitazone, on colon cancer cells.
The effect of fucoxanthin, from the edible seaweed Undaria pinnatifida on viability of colon cancer cells and induction of apoptosis was investigated. Fucoxanthin remarkably reduced the viability of human colon cancer cell lines, Caco-2, HT-29 and DLD-1. Furthermore, treatment with fucoxanthin induced DNA fragmentation, indicating apoptosis. The DNA fragmentation in Caco-2 cells treated with 22.6 microM fucoxanthin for 24 h was 10-fold higher than in the control. Fucoxanthin suppressed the level of Bcl-2 protein. Also, DNA fragmentation induced by fucoxanthin was partially inhibited by a caspase inhibitor Z-VAD-fmk. Moreover, combined treatment with 3.8 microM fucoxanthin and 10 microM troglitazone, which is a specific ligand for peroxisome proliferator-activated receptor (PPAR) gamma, effectively decreased the viability of Caco-2 cells. However, separate treatments with these same concentrations of fucoxanthin nor troglitazone did not affect cell viability. These findings indicate that fucoxanthin may act as a chemopreventive and/or chemotherapeutic carotenoid in colon cancer cells by modulating cell viability in combination with troglitazone.
Hosokawa
Masashi
M
Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato, Hakodate, Hakodate, Hokkaido 041-8611, Japan. hoso@fish.hokudai.ac.jp
Kudo
Masahiro
M
Maeda
Hayato
H
Kohno
Hiroyuki
H
Tanaka
Takuji
T
Miyashita
Kazuo
K
D000970:Antineoplastic Agents / Q000494:pharmacology*; D000971:Antineoplastic Combined Chemotherapy Protocols; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002839:Chromans / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008024:Ligands; D047495:PPAR gamma / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D045162:Thiazolidinediones / Q000494:pharmacology*; D000077288:Troglitazone; D014407:Tumor Cells, Cultured; D024341:Xanthophylls / Q000494:pharmacology*
D000970:Antineoplastic Agents; D002839:Chromans; D008024:Ligands; D047495:PPAR gamma; D019253:Proto-Oncogene Proteins c-bcl-2; D045162:Thiazolidinediones; D024341:Xanthophylls; C025164:fucoxanthin; D020169:Caspases; D000077288:Troglitazone