title: [Effect of equol on breast tumors induced by 7, 12-dimethylbenz (α) anthracene in ovariectominzed rats].
abstract: OBJECTIVE
  To study the effect of equol on the incidence of breast tumors induced by 7, 12-dimethylbenz(α) anthracene (DMBA) in ovariectomized rats.
  
  
  METHODS
  In the study, 48 female ovariectomized SD rats were randomly divided into 6 groups according to their weights: blank control group, fed on an AIN-93G diet; model group, fed on an AIN-93G diet; estrogen control group, fed on an AIN-93G diet supplemented with 0.25 mg/kg diethylstilbestrol; and low, medium and high doses of equol groups, fed on an AIN-93G diet supplemented with 100, 200 and 400 mg/kg diet of equol, respectively. The animals were palpated to examine the breast tumor, body weight and dietary intake of each rat per week. The data were recorded. At the end of the experiment, the incidence of breast tumor was calculated and the sera were collected for the detection of SOD, MDA and 8-OHdG levels. The expression of Nrf2 in liver was assessed by Western-blotting.
  
  
  RESULTS
  Equol decreased the rats' body weights, dietary intakes, breast tumor incidence and MDA levels, but had no effect on the levels of SOD and 8-OHdG in the sera. The expression of Nrf2 was up-regulated dose-dependently in equol groups.
  
  
  CONCLUSIONS
  Supplementation of equol could decrease the incidence of breast tumor in ovariectominzed rats. This effect may result from the reduction of body weight, intake of diet, MDA level in the sera and up-regulation of expression of Nrf2. The effect of equol may be influenced by many factors, such as the structure of equol, which should be further studied.
authors.affiliation: Department of Nutrition and Food Hygiene, Peking University School of Public Health, Beijing 100191, China.
authors.forename: Xiao Hui
authors.initials: XH
authors.lastname: Zhao
authors.forename: Jian Wei
authors.initials: JW
authors.lastname: Hu
authors.forename: Yu Mei
authors.initials: YM
authors.lastname: Zhang
authors.forename: Pei Yu
authors.initials: PY
authors.lastname: Wang
mesh_terms: D000818:Animals; D001551:Benz(a)Anthracenes; D001943:Breast Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D060754:Equol / Q000008:administration & dosage* / Q000627:therapeutic use; D005260:Female; D008315:Malondialdehyde / Q000032:analysis / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D001551:Benz(a)Anthracenes; D051267:NF-E2-Related Factor 2; C495637:Nfe2l2 protein, rat; C046810:7,12-dihydroxymethylbenz(a)anthracene; D008315:Malondialdehyde; D060754:Equol