Absence of chemopreventive influence of propolis on the rat liver altered foci development
Nenhuma Miniatura disponível
Data
2010-07-01
Autores
Said, Roueda Abou
Grassi, Tony Fernando [UNESP]
Scolastici, Clarissa [UNESP]
Alves de Lima, Rodrigo Otavio [UNESP]
Darros, Bruno R. [UNESP]
Barbisan, Luis Fernando [UNESP]
Camargo, João Lauro Viana de [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Elsevier Gmbh, Urban & Fischer Verlag
Resumo
Propolis (bee glue) is a complex mixture of natural substances that exhibits a broad spectrum of biological activities. As the possibility exists that it may exert a chemopreventive role against cancer development, the present study aimed to evaluate the chemopreventive influence of a Brazilian aqueous propolis extract (APE) in a rat two-stage (initiation-promotion) medium-term bioassay for chemical liver carcinogenesis. Male Wistar rats were sequentially initiated with diethylnitrosamine (DEN, 200 mg/kg b.w.) and, 2 weeks later, exposed to a diet containing hexachlorobenzene (HCB, 100 ppm) and to APE 0.1% through drinking water for 6 weeks. Appropriate control groups were also established. The animals were sacrificed at the weeks 8th and 30th when liver samples were processed to evaluate the development of altered hepatocyte foci (AHF) identified under hematoxylin and eosin (H&E) staining and by the immunohistochemical expression of the enzyme glutathione S-transferase placental form (GST-P). The results indicate that APE 0.1% did not protect against the development of any of the differentially identified putative preneoplastic foci in DEN-initiated animals, exposed or not to the promoting agent HCB. Also, APE 0.1% by itself did not significantly induce any AHF, what is in line with its already known absence of genotoxic potential. Our results indicate that an aqueous extract of Brazilian propolis did not exert chemoprevention on the hepatocarcinogenesis process chemically induced in the rat. (C) 2009 Elsevier GmbH. All rights reserved.
Descrição
Palavras-chave
Propolis, Diethylnitrosamine, Hexachlorobenzene, GST-P-positive foci, Hepatocarcinogenesis, Wistar rats
Como citar
Experimental and Toxicologic Pathology. Jena: Elsevier Gmbh, Urban & Fischer Verlag, v. 62, n. 4, p. 405-412, 2010.