Modifying effects of propolis on MeIQx promotion of rat hepatocarcinogenesis and in a female rat two-stage carcinogenesis model after multiple carcinogen initiation

Citation
M. Kawabe et al., Modifying effects of propolis on MeIQx promotion of rat hepatocarcinogenesis and in a female rat two-stage carcinogenesis model after multiple carcinogen initiation, NUTR CANCER, 37(2), 2000, pp. 179-186
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Oncology,"Onconogenesis & Cancer Research
Journal title
NUTRITION AND CANCER-AN INTERNATIONAL JOURNAL
ISSN journal
0163-5581 → ACNP
Volume
37
Issue
2
Year of publication
2000
Pages
179 - 186
Database
ISI
SICI code
0163-5581(2000)37:2<179:MEOPOM>2.0.ZU;2-V
Abstract
The modifying effects of the dietary administration of water- and ethanol-e xtracted propolis produced in Brazil (WB and EB, respectively) on 2-amino-3 , 8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) promotion of rat hepatocarcin ogenesis were investigated in a medium-term liver bioassay system with use of male Fischer 344 rats. The number and area of glutathione S-transferase placental form (GST-P)-positive foci in rats given 0.5% WB were significant ly increased compared with the group given MeIQx alone. Furthermore, the nu mbers of GST-P-positive foci were higher in rats given 0.1% WB or EB than i n those given the basal diet alone. The modifying effects of propolis on ot her organs were also examined in female Fischer 344 rats given multiple car cinogens for initiation. Rats received water- and ethanol-extracted propoli s produced in Brazil and Uruguay (WB, EB, WU, and EU, respectively) in the diet after exposure to three different carcinogens. The incidence of total mammary tumors was significantly lower in rats given EU than in the control group. These results indicate that a water extract of propolis exerts a co carcinogenic effect on MeIQx hepatocarcinogenesis while promoting the effec t at low dose in a two-stage hepatocarcinogenesis model Moreover, they sugg est that ethanol-extracted propolis may be an inhibitor of mammary gland ca rcinogenesis.