Protective action of propolis on the rat colon carcinogenesis.
Propolis is a honeybee product with several biological and therapeutical properties. Its effect on the process of colon carcinogenesis and DNA damage were evaluated in the male Wistar rats using the aberrant crypt foci (ACF) assay and the comet assay, respectively. For both tests, animals were treated with the colon carcinogen 1,2 dimethylhydrazine (DMH, 40 mg/kg, s.c.) for 2 weeks (two injections/week) in order to induce both DNA damage and ACF. The animals were divided into groups that received propolis (ethanolic extract) at three different doses (10, 30, and 90 mg/kg b.w., by gavage), either simultaneously or after DMH treatment. For the comet assay, peripheral blood samples were collected 4 h after the last DMH treatment. All animals were sacrificed at the 5th week for evaluation of ACF. The results show that only the intermediate dose (30 mg/kg) of propolis, administered after DMH initiation, is significantly associated to a smaller number of aberrant crypts in the distal colon. No effect on DNA damage in peripheral blood cells, however, was verified by the comet assay. These data suggest that propolis has a protective influence on the process of colon carcinogenesis, suppressing the development of preneoplastic lesions, and probably exerts no protection against the initiation of carcinogenesis.
Bazo
Ana Paula
AP
Departamento de Patologia, Faculdade de Medicina, UNESP, Botucatu, São Paulo, Brazil.
Rodrigues
Maria Aparecida Marchesan
MA
Sforcin
José Maurício
JM
de Camargo
João Lauro Viana
JL
Ribeiro
Lúcia Regina
LR
Salvadori
Daisy Maria Fávero
DM
D019813:1,2-Dimethylhydrazine; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D002273:Carcinogens; D003110:Colonic Neoplasms / Q000517:prevention & control*; D020552:Comet Assay; D004247:DNA / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects; D008297:Male; D011429:Propolis / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D000890:Anti-Infective Agents; D016588:Anticarcinogenic Agents; D002273:Carcinogens; D004247:DNA; D011429:Propolis; D019813:1,2-Dimethylhydrazine