title: Decrease in size of azoxymethane induced colon carcinoma in F344 rats by 180-day fermented miso.
abstract: The present study was designed to investigate the effects of fermented miso (fermented soybean paste) on the induction of colon tumors by azoxymethane (AOM) in male F344 rats. A total of 91 rats, 6 weeks of age, were divided into 5 groups and given weekly subcutaneous injections of AOM (15 mg/kg body wt) for 3 weeks. The animals were placed on diets one week before the first AOM dose: commercial normal control MF diet or a diet containing 10% 2-year, 180-day fermented, or 3-4-day fermented miso. There were no differences in body and organ weights, and no aberrant crypt foci (ACF) among carcinogen-treated groups at week 25. The rates of tumor incidence were 45%, 85%, 75% and 60% with the 2-year, 180-day, and 3-4-day fermented miso and MF, respectively, and those for colon tumors were 34%, 55%, 60% and 55%, respectively. The size of well-differentiated adenocarcinomas and total (well differentiated and signet ring cell) adenocarcinomas in the 180-day fermented miso group was significantly smaller than that in the 2-year fermented miso and MF+AOM groups. Nuclear staining of beta-catenin in colon tumors was increased for the 3-4-day fermented miso compared to the 180-day fermented miso. Cdx2 staining tendency was decreased in colon tumors and adenocarcinomas compared to normal mucosa and ACF, which stained in 100% of cases. In addition, the PCNA index was significantly reduced in the 180-day group compared with those groups receiving the 3-4-day fermented miso and MF diet. The germinal region was also decreased. The present results indicate that dietary supplementation with 180-day fermented dietary miso could act as a chemopreventive agent for colon carcinogenesis.
authors.affiliation: Department of Health Science, Hiroshima Prefectural Women's University, 1-1-71 Ujina-higashi, Minami-ku, Hiroshima 734-8558, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Ohuchi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Myojin
authors.forename: Fumio
authors.initials: F
authors.lastname: Shimamoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Kashimoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Kamiya
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001397:Azoxymethane / Q000008:administration & dosage / Q000633:toxicity; D002273:Carcinogens / Q000008:administration & dosage / Q000633:toxicity; D049109:Cell Proliferation / Q000187:drug effects; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D019587:Dietary Supplements; D005285:Fermentation; D007150:Immunohistochemistry; D007279:Injections, Subcutaneous; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D045730:Soy Foods; D013997:Time Factors; D051176:beta Catenin / Q000032:analysis
chemical_list: D002273:Carcinogens; D018809:Proliferating Cell Nuclear Antigen; D051176:beta Catenin; D001397:Azoxymethane