Wakame seaweed suppresses the proliferation of 7,12-dimethylbenz(a)-anthracene-induced mammary tumors in rats

Hiroomi Funahashi, Tsuneo Imai, Yuji Tanaka, Kyousuke Tsukamura, Yasusyuki Hayakawa, Toyone Kikumori, Takahiro Mase, Takahiro Itoh, Mikiko Nishikawa, Hiromiti Hayashi, Arihiro Shibata, Yatsuka Hibi, Masahide Takahashi, Tatsuhiko Narita

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86 Citations (Scopus)

Abstract

We examined the anti-tumor proliferation effects of wakame seaweed on 7,12-dimethylbenz(a)-anthracene (DMBA)-induced rat mammary tumor. DMBA was administered to 8-week-old female Sprague-Dawley rats, and rats which developed mammary tumors were assigned randomly to three groups. Commercial rat feed was used in a control group (group I-A), and two feed mixtures were prepared, which contained commercial rat feed blended with wakame at 1.0% (group I-B) and 5.0% (group I-C) by weight. The respective feeds were given to each group for 8 weeks, and changes in mammary tumor size were compared. At the end of the experiment, mammary tumors and thyroid glands were resected to compare their weights. Serum total iodine and thyroxin (T4) levels were measured. Immunohistochemical studies for bromodeoxyuridine (BrdU) labeling, transforming growth factor (TGF)-β, and apoptosis were carried out in the resected tumor. Significant suppression of tumor growth was observed in groups I-B and I-C compared with I-A. In groups I-B and I-C, the weights of resected mammary tumors were significantly lower and serum total iodine concentration was significantly higher than in I-A. BrdU indices were significantly lower in groups I-B and I-C, compared with I-A. TGF-β and apoptotic index were inversely related to BrdU. These results suggest that iodine is transported from the serum into mammary tissues and induces apoptosis through the expression of TGF-β. In conclusion, wakame suppressed the proliferation of DMBA-induced mammary tumors.

Original languageEnglish
Pages (from-to)922-927
Number of pages6
JournalJapanese Journal of Cancer Research
Volume90
Issue number9
DOIs
Publication statusPublished - 09-1999
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Oncology
  • Cancer Research

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