Estudo do potencial antigenotóxico da Baccharis dracunculiolia em células V79 e ratos Wistar pelo ensaio do cometa e antimutagênico usando o teste de ames

• Ano de defesa: 2010
• Autor(a) principal: Munari, Carla Carolina
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade de Franca; Brasil; Pós-Graduação; Programa de Mestrado em Ciências; UNIFRAN
• Palavras-chave em Português: Baccharis dracunculifolia; Própolis verde; Ensaio cometa; Células V79; Células do cólon; Teste de Ames; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA HUMANA E MEDICA
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/829

In the present study are presented the results of the evaluation of possible genotoxicity and/or antigenotoxicity of the ethyl acetate extract of B. dracunculifolia (Bd-EAE) in fribroblasts of Chinese hamster lung (V79) and cells colon of rats by the Comet assay, and evaluating mutagenic and antimutagenic in Salmonella typhimurium by the Ames test. For the evaluation of genotoxicity in vitro, we have used four different concentrations of BdEAE, which were 12.5; 25.0; 50.0 e 100.0 μg/mL. The potential antigenotoxicity of Bd-EAE was studied considering different protocols: pre, simultaneous and post-treatment with the genotoxic compound methyl methanesulfonate (MMS, 22 µg/mL). Concentrations of BdEAE were determined from the test of colonic formation and the viability of the method by trypan blue exclusion. The results showed that cultures treated with 50.0 and 100.0 μg/mL of Bd-EAE showed significant increase of DNA damage in comparison with not treated in any way. Regarding antigenotoxicity, the Bd-EAE reduced the frequency of DNA damage induced by MMS. However, the chemopreventive activity was dependent on concentration, as well as on the treatment protocols used. For the in vivo assessement of genotoxicity, it was used a dose of 24 mg/kg b. w., which showed levels of DNA damage that did not differ from the negative control. Doses of 6, 12 and 24 mg/kg b. w. associated with the carcinogen 1,2-dimethylhydrazine (DMH, 40 mg/kg p.c.) showed a statistically significant reduction in the group with DMH only. For the test of Salmonella/microssome, five different concentrations of Bd-EAE were tested: 11,4; 22,8; 45,6; 91,4 and 182,8 μg/plate in strains TA98, TA100, TA102 and TA97a of Salmonella typhimuium in the presence and absence of microsomal fraction (S9). The results showed no statistically significant differences in the number of revertants/plate in the control group. When the Bd-EAE was associated with the mutagen 4-nitro-o-fenilenodiamino, it showed an inhibitory effect on the number of revertants/plate for strain of TA97a. Key works: Baccharis dracunculifolia, Green Propolis, Comet assay, V79 cells, cells of the colon, Ames test.