PMID- 11810047
OWN - NLM
STAT- MEDLINE
DCOM- 20020307
LR  - 20180213
IS  - 0030-2414 (Print)
IS  - 0030-2414 (Linking)
VI  - 62
IP  - 1
DP  - 2002
TI  - Anticarcinogenic effects of isoflavones may be mediated by genistein in mouse 
      mammary tumor virus-induced breast cancer.
PG  - 78-84
AB  - Isoflavones are known to exert anticancer effects. These effects were examined 
      using two isoflavones, biochanin A and daidzein, in a mouse mammary tumor virus 
      (MMTV)-induced spontaneous breast cancer model. Emphasis was placed on isoflavone 
      metabolism by the intestinal microflora and changes in estrogen levels. Germ-free 
      (Gf) mice and their conventionalized (Cv) counterparts were assigned to three 
      diet groups: (1) control diet, (2) biochanin A and (3) daidzein. In all groups, 
      urine was collected from virgin female mice to analyze isoflavone metabolism by 
      high performance liquid chromatography. These studies revealed changes of 
      biochanin A into genistein, and of daidzein into equol, which were accelerated in 
      the Cv animals. However, the Gf mice could not transform biochanin A into 
      genistein, or daidzein into equol. Estrogen levels in the control and daidzein 
      diet groups were lower in the Gf mice than in the Cv mice. The biochanin A group 
      showed no differences in estrogen levels between the Cv and Gf animals. 
      Four-week-old male and female animals were paired in the Gf and Cv groups. The 
      female animals delivered and lactated repeatedly and were observed for the 
      development of mammary cancer by palpation, twice weekly, until 15 months of age. 
      The Cv mice showed a significantly lower incidence of breast cancer in the 
      biochanin A diet group than in the control or daidzein groups (p < 0.05). These 
      results suggest that the anticarcinogenic effects in this system might be 
      produced not by daidzein or equol, but by biochanin A and/or genistein. In the Gf 
      animals, the incidence of breast cancer was significantly higher in the biochanin 
      A group than in the control group (p < 0.05), probably due to the increased level 
      of estradiol in the former group. The biochanin A group tended to have a higher 
      incidence of breast cancer than the daidzein group in the Gf group, although no 
      significant differences were noted. Thus, no anticarcinogenic effect was produced 
      by biochanin A alone in the Gf mice. In view of the results presented, genistein 
      derived from biochanin A following metabolic processes in the intestinal 
      microflora most likely acts as an inhibitor in breast carcinogenesis; biochanin A 
      is most likely a precursor of genistein.
CI  - Copyright 2002 S. Karger AG, Basel
FAU - Mizunuma, Hirobumi
AU  - Mizunuma H
AD  - Department of Surgery, Jichi Medical School, Tochigi, Japan. 
      cl-mizu0001@nifty.com
FAU - Kanazawa, Kyotaro
AU  - Kanazawa K
FAU - Ogura, Shigeto
AU  - Ogura S
FAU - Otsuka, Shin
AU  - Otsuka S
FAU - Nagai, Hideo
AU  - Nagai H
LA  - eng
PT  - Journal Article
PL  - Switzerland
TA  - Oncology
JT  - Oncology
JID - 0135054
RN  - 0 (Anticarcinogenic Agents)
RN  - 0 (Estrogens)
RN  - 0 (Isoflavones)
RN  - 6287WC5J2L (daidzein)
RN  - DH2M523P0H (Genistein)
RN  - U13J6U390T (biochanin A)
SB  - IM
MH  - Animals
MH  - Anticarcinogenic Agents/*metabolism/*pharmacology/therapeutic use
MH  - Biotransformation
MH  - Body Weight
MH  - Breast Neoplasms/diet therapy/*pathology/prevention & control/*virology
MH  - Diet
MH  - Estrogens/urine
MH  - Female
MH  - Genistein/*metabolism/pharmacology/therapeutic use/urine
MH  - Germ-Free Life
MH  - Incidence
MH  - Isoflavones/metabolism/*pharmacology/therapeutic use/urine
MH  - Male
MH  - Mammary Tumor Virus, Mouse/*physiology
MH  - Mice
EDAT- 2002/01/26 10:00
MHDA- 2002/03/08 10:01
CRDT- 2002/01/26 10:00
PHST- 2002/01/26 10:00 [pubmed]
PHST- 2002/03/08 10:01 [medline]
PHST- 2002/01/26 10:00 [entrez]
AID - ocl62078 [pii]
AID - 10.1159/000048250 [doi]
PST - ppublish
SO  - Oncology. 2002;62(1):78-84. doi: 10.1159/000048250.