title: Selenium as a chemopreventive agent in experimentally induced colon carcinogenesis.
abstract: OBJECTIVE
  To elucidate the chemopreventive efficacy of selenium during experimentally induced colon carcinogenesis.
  
  
  METHODS
  Thirty-two male wistar rats were divided into four groups: group I (normal control); group II [1,2-dimethylhydrazine (DMH) treated]; group III (selenium treated); and group IV (DMH + selenium treated). Groups II and IV were given subcutaneous injections of DMH (30 mg/kg body weight) every week for 20 wk. Selenium, in the form of sodium selenite, was given to groups III and IV at 1 ppm in drinking water ad libitum for 20 wk. At the end of the study, rats were sacrificed and their colons were analyzed for the development of tumors, antioxidant enzyme levels and histological changes.
  
  
  RESULTS
  100% of the DMH treated rats developed tumors, which was reduced to 60% upon simultaneous selenium supplementation. Similarly, tumor multiplicity decreased to 1.1 following selenium supplementation to DMH treated rats. Levels of lipid peroxidation, glutathione-S-transferase, superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) decreased following DMH treatment, whereas levels of glutathione (GSH) and glutathione reductase (GR) significantly increased in DMH treated rats. Selenium administration to DMH treated rats led to an increase in the levels of lipid peroxidation, SOD, catalase, glutathione-S-transferase and GPx, but decreased the levels of GSH and GR. Histopathological studies on DMH treated rats revealed dysplasia of the colonic histoarchitecture, which showed signs of improvement following selenium treatment.
  
  
  CONCLUSIONS
  The study suggests the antioxidative potential of selenium is a major factor in providing protection from development of experimentally induced colon carcinogenesis.
authors.affiliation: Fereshteh Ezzati Ghadi, Abdollah Ramzani Ghara, Devinder Kumar Dhawan, Department of Biophysics, Basic Medical Sciences Block, Panjab University, Chandigarh, PIN-160014, India.
authors.forename: Fereshteh Ezzati
authors.initials: FE
authors.lastname: Ghadi
authors.forename: Abdollah Ramzani
authors.initials: AR
authors.lastname: Ghara
authors.forename: Shalmoli
authors.initials: S
authors.lastname: Bhattacharyya
authors.forename: Devinder Kumar
authors.initials: DK
authors.lastname: Dhawan