title: Preventive effect of fermented brown rice and rice bran against colon carcinogenesis in male F344 rats.
abstract: Epidemiological and preclinical studies demonstrate that nutrition plays an important role in the etiology of cancer. It has been reported that rice components, especially rice germ plays a key role in prevention of cancer. The experiments described here examined the potential anticancer properties of brown rice fermented by Aspergillus Oryzae (FBRA) in male F344 rats using inhibition of the formation of azoxymethene (AOM) induced aberrant crypt foci (ACF) and tumors in the colon as the measure of preventive efficacy. The agent was administered at 2.5 and 5% levels in the diet during the initiation phase (during and until 1 week after carcinogen treatment) and/or post-initiation phase (beginning 1 week after carcinogen treatment) of carcinogenesis. In the ACF and tumor studies, rats were sacrificed 5 or 40 weeks after the initiation of AOM treatment (15 mg/kg body weight, once weekly for 3 weeks), respectively. Colonic ACF and tumors were evaluated histopathologically. Administration of 2.5 and 5% FBRA in the diet continuously during initiation and post-initiation period significantly inhibited the ACF formation in rats treated with AOM, compared with rats treated with AOM alone (99+/-24.1 and 79+/-18.4 vs. 139.5+/-27.7, respectively). In addition, administration of 5% FBRA in the diet during the post-initiation phase significantly suppressed the incidence (44 vs.18%) and multiplicity (0.93+/-0.96 vs. 0.18+/-0.40) of colon adenocarcinomas as compared to those given the control diet. In addition, 5% FBRA in the diet during post-initiation phase caused significant inhibition of cell proliferation in the colonic mucosa as compared to the group fed the control diet (81% reduction, p<0.05). These observations demonstrated for the first time that FBRA inhibits colon tumor development in rats, and suggest that it is a promising dietary supplement for prevention of human colon cancer.
authors.affiliation: Department of Pathology, Gifu University School of Medicine, Gifu 500-8705, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Katyama
authors.forename: Naoki
authors.initials: N
authors.lastname: Yoshimi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamada
authors.forename: Keiko
authors.initials: K
authors.lastname: Sakata
authors.forename: Toshiya
authors.initials: T
authors.lastname: Kuno
authors.forename: Koujiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Zheng
authors.initials: Z
authors.lastname: Qiao
authors.forename: Pham Quang
authors.initials: PQ
authors.lastname: Vihn
authors.forename: Teruaki
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Mori
mesh_terms: D000818:Animals; D001397:Azoxymethane / Q000633:toxicity; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens / Q000633:toxicity; D003106:Colon / Q000187:drug effects / Q000473:pathology; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D005285:Fermentation; D015994:Incidence; D007413:Intestinal Mucosa / Q000187:drug effects / Q000473:pathology; D008297:Male; D012275:Oryza; D008517:Phytotherapy; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002273:Carcinogens; D018809:Proliferating Cell Nuclear Antigen; D001397:Azoxymethane