title: Contribution of the antioxidative property of astaxanthin to its protective effect on the promotion of cancer metastasis in mice treated with restraint stress.
abstract: We investigated the effects of astaxanthin on the antitumor effector activity of natural killer (NK) cells suppressed by stress in mice in order to define the immunological significance of astaxanthin (ASX) when combined with restraint stress treatment. When the mice were treated with restraint stress alone, the total number of spleen cells, and the level NK cell activity per spleen were reduced to a nadir on day 3. The stress also caused a significant increase in the lipid peroxidation of liver tissue. ASX (100 mg/kg/day, p.o., 4 days) improved the immunological dysfunction induced by restraint stress. On the other hand, metastatic nodules were observed in the livers of syngenic DBA/2 mice on day 12 after inoculation of P815 mastocytoma cells. Hepatic metastasis was promoted further by restraint stress when applied on day 3 before the inoculation of P815. Daily oral administration of ASX (1 mg/kg/day, p.o., 14 days) markedly attenuated the promotion of hepatic metastasis induced by restraint stress. These results suggested that astaxanthin improves antitumor immune responses by inhibiting of lipid peroxidation induced by stress.
authors.affiliation: Institute for Health Care Science, Suntory Ltd., 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618-8503, Japan. Hiroshi_Kurihara@suntory.co.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kurihara
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Koda
authors.forename: Sumio
authors.initials: S
authors.lastname: Asami
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Kiso
authors.forename: Takaharu
authors.initials: T
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use*; D000975:Antioxidants / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use*; D002478:Cells, Cultured; D005260:Female; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008113:Liver Neoplasms / Q000517:prevention & control / Q000556:secondary; D012515:Mast-Cell Sarcoma / Q000473:pathology / Q000517:prevention & control; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D009368:Neoplasm Transplantation / Q000473:pathology; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000473:pathology*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured; D024341:Xanthophylls; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D007166:Immunosuppressive Agents; D017392:Thiobarbituric Acid Reactive Substances; D024341:Xanthophylls; D019207:beta Carotene; C005948:astaxanthine