title: No effects of olive oils with different phenolic content compared to corn oil on 1,2-dimethylhydrazine-induced colon carcinogenesis in rats.
abstract: BACKGROUND
  Some epidemiological and experimental studies suggest that olive oil, despite its elevated caloric content, may have protective activity against colon cancer, partially due to its phenolic content. However, little experimental evidence exists to support this claim in vivo.
  
  
  OBJECTIVE
  To test the effect of olive oils with different phenolic content in a well-characterized model of colon carcinogenesis, comparing them with corn oil (CO).
  
  
  METHODS
  F344 rats were fed AIN-76 based diets for the entire experimental period; the diets contained 23% (w/w) of lipids from three different sources: extra-virgin olive oil rich in phenolic compounds (EV), rectified olive oil (ROO) with the same fatty acid composition but devoid of phenolic compounds and CO as a control diet. One week later, rats were induced with 1,2-dimethylhydrazine (DMH) (150 mg/kg b.w. x 2 times) to measure preneoplastic lesions (aberrant crypt foci (ACF) and mucin depleted foci (MDF)) and tumours in the intestine.
  
  
  RESULTS
  Thirteen weeks after DMH, the numbers of ACF and MDF were similar in the different groups (ACF/colon were 344.9 +/- 27.0, 288.6 +/- 28.5 and 289.8 +/- 21.4 in CO, EV and ROO groups, respectively, means +/- SE; MDF/colon were 8.83 +/- 1.2, 8.41 +/- 1.5 and 8.75 +/- 1.6 in CO, EV and ROO groups, respectively, means +/- SE). Thirty-two weeks after DMH, the incidence of tumours (rats with tumours/rats in the group) did not differ among the different groups (20/21, 18/19 and 20/20 in the CO, EV, and ROO groups, respectively). Similarly, the number of tumours/ rat in the colorectum (both adenomas and cancers) was not different in the three different groups (2.33 +/- 0.26, 2.42 +/- 0.41 and 2.25 +/- 0.40 in CO, EV and ROO groups, respectively, means +/- SE).
  
  
  CONCLUSIONS
  Olive oil, irrespective of its phenolic content, does not affect DMH-induced colon carcinogenesis in F344 rats compared with CO.
authors.affiliation: Dept of Pharmacology, University of Florence, Florence, Italy.
authors.forename: Angelo Pietro
authors.initials: AP
authors.lastname: Femia
authors.forename: Piero
authors.initials: P
authors.lastname: Dolara
authors.forename: Maurizio
authors.initials: M
authors.lastname: Servili
authors.forename: Sonia
authors.initials: S
authors.lastname: Esposto
authors.forename: Agnese
authors.initials: A
authors.lastname: Taticchi
authors.forename: Stefania
authors.initials: S
authors.lastname: Urbani
authors.forename: Augusto
authors.initials: A
authors.lastname: Giannini
authors.forename: Maddalena
authors.initials: M
authors.lastname: Salvadori
authors.forename: Giovanna
authors.initials: G
authors.lastname: Caderni
mesh_terms: D019813:1,2-Dimethylhydrazine / Q000633:toxicity; D000818:Animals; D002273:Carcinogens / Q000633:toxicity; D003106:Colon / Q000187:drug effects* / Q000473:pathology*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000453:epidemiology* / Q000473:pathology; D003314:Corn Oil; D008297:Male; D000069463:Olive Oil; D010636:Phenols / Q000494:pharmacology*; D010938:Plant Oils / Q000032:analysis* / Q000737:chemistry; D011897:Random Allocation; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002273:Carcinogens; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D003314:Corn Oil; D019813:1,2-Dimethylhydrazine