title: Effect of black tea in diethylnitrosamine-induced esophageal carcinogenesis in mice.
abstract: OBJECTIVE
  To evaluate the effect of black tea on esophageal carcinogenesis induced by the oral administration of diethylnitrosamine (DEN).
  
  
  METHODS
  A population of 120 female mice (Mus musculus, strain CF1) were studied for 160 days. The animals were assigned to two control groups and three treatment groups. The control groups received water or tea throughout the study period, while the three experimental groups received DEN weekly, for three consecutive days, and water, tea, or both, in the other days of the week. On completion of the 160-day period, the animals were killed and their esophagi promptly examined macroscopically and subsequently submitted to histopathology (using the hematoxylin-eosin technique).
  
  
  RESULTS
  In the comparative analysis between the treatment groups, tumor incidence (macroscopy) was significantly lower in those animals that received black tea besides the carcinogen. As regards the histopathologic changes, there was a greater number of low grade epithelial lesions in the same groups (p < 0.001).
  
  
  CONCLUSIONS
  The animals that received black tea had a lower incidence of effects related to the carcinogen's action, thus indicating that, in this model, the infusion had a significant chemoprophylactic effect on experimental diethylnitrosamine-induced carcinogenesis.
authors.affiliation: Surgery Department, UFCSPA, Brazil. atila.velho@terra.com.br
authors.forename: Atila Varela
authors.initials: AV
authors.lastname: Velho
authors.forename: Antonio Atalíbio
authors.initials: AA
authors.lastname: Hartmann
authors.forename: Cleber Dario Pinto
authors.initials: CD
authors.lastname: Kruel
mesh_terms: D000477:Alkylating Agents; D000818:Animals; D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D002273:Carcinogens; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D004052:Diethylnitrosamine; D004353:Drug Evaluation, Preclinical; D004938:Esophageal Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D051379:Mice; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use; D011897:Random Allocation; D013662:Tea / Q000737:chemistry*
chemical_list: D000477:Alkylating Agents; D016588:Anticarcinogenic Agents; D002273:Carcinogens; D010936:Plant Extracts; D013662:Tea; D004052:Diethylnitrosamine