Post-initiation effects of a super critical extract of propolis in a rat two-stage carcinogenesis model in female F344 rats

Citation
N. Kimoto et al., Post-initiation effects of a super critical extract of propolis in a rat two-stage carcinogenesis model in female F344 rats, CANCER LETT, 147(1-2), 1999, pp. 221-227
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Onconogenesis & Cancer Research
Journal title
CANCER LETTERS
ISSN journal
0304-3835 → ACNP
Volume
147
Issue
1-2
Year of publication
1999
Pages
221 - 227
Database
ISI
SICI code
0304-3835(199912)147:1-2<221:PEOASC>2.0.ZU;2-7
Abstract
Post-initiation modifying effects of dietary administration of a super crit ical extract of propolis on major organs were examined using a two-stage ca rcinogenesis model. Groups of 21 or 22 F344 female rats were treated sequen tially with 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN, i.g.), 7,12-dimeth ylbenz[a]anthracene (DMBA, i.g.), 1,2-dimethylhydrazine (DMH, s.c.) and N-b utyl-N-(4-hydroxybutyl)nitrosamine (BBN, in drinking water) during the firs t 3 weeks for initiation, and then administered diet containing 0.1 or 0.01 % propolis for 33 weeks. Further groups were treated with the carcinogens a lone, 0.1% propolis alone or basal diet alone. All surviving animals were k illed at week 36, and major organs were examined histopathologically for de velopment of preneoplastic and neoplastic lesions. The incidence and multip licity of mammary carcinomas were significantly decreased by the 0.1 and 0. 01% propolis treatments. In the urinary bladder, the incidence of PN hyperp lasia but not tumors was, in contrast, significantly increased by 0.1% prop olis. Similarly, the number and area of glutathione S-transferase placental form (GST-P)-positive liver foci were significantly elevated with this hig h dose. The results indicate that a low dose of a super critical extract of propolis may find application as a potent chemopreventor of mammary carcin ogenesis. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.