Prevention by long-term fermented miso of induction of colonic aberrant crypt foci by azoxymethane in F344 rats.
The present study was designed to investigate the effects of fermented miso in the diet on the induction of aberrant crypt foci (ACF) by azoxymethane (AOM) in male F344 rats. A total of 50 rats, 8 weeks of age, were divided into 5 groups and given weekly subcutaneous injections of AOM (15 mg/kg body wt) for 3 weeks. Rats were fed a normal control MF solid diet, or solid diet containing 10% long-term fermented (aged), medium- or short-term fermented miso, or 2.2% NaCl for 5 weeks, starting one week before the first AOM dosing. It was found that, compared to the control (MF) diet, the long-term fermented diet significantly decreased (by 22.2%) ACF/colon, but increased (by 18.2%) the number of aberrant crypts (Acs)/focus. The latter was also increased by the medium-term fermented diet (by 25.3%). The PCNA labeling index was only affected by the short-term fermented diet (36.9% increase) and by 2.2% NaCl diet (27.2% increased). The present results indicate that aged or completely fermented miso supplemented into the diet, could act as a chemopreventive agent for colon carcinogenesis.
Ohara
Masayuki
M
Department of Environment and Mutation, Research Institute for Radiation Biology and Medicine, Hiroshima University, Minami-ku, Hiroshima 734-8553, Japan.
Lu
Huimei
H
Shiraki
Katsutomo
K
Ishimura
Yoshiyuki
Y
Uesaka
Toshihiro
T
Katoh
Osamu
O
Watanabe
Hiromitsu
H
D000818:Animals; D001397:Azoxymethane / Q000633:toxicity; D001835:Body Weight; D002273:Carcinogens / Q000633:toxicity; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000178:diet therapy* / Q000378:metabolism; D004044:Dietary Proteins / Q000008:administration & dosage*; D005285:Fermentation; D007124:Immunoenzyme Techniques; D008297:Male; D009929:Organ Size; D011230:Precancerous Conditions / Q000139:chemically induced / Q000178:diet therapy* / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D030262:Soybean Proteins / Q000008:administration & dosage*
D002273:Carcinogens; D004044:Dietary Proteins; D018809:Proliferating Cell Nuclear Antigen; D030262:Soybean Proteins; D001397:Azoxymethane