Estudo da atividade mutagênica e/ou antimutagênica da Baccharis dracunculifolia em células de mamíferos in vivo e in vitro

• Ano de defesa: 2008
• Autor(a) principal: Resende, Flávia Aparecida
• 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; Micronúcleos; Aberrações cromossômicas; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA HUMANA E MEDICA
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/830

The plant Baccharis dracunculifolia DC (Asteraceae), popularly known as “alecrim do campo” and “vassoura”, is native to Brazil. Because this plant is believed to be the most important botanical source of green propolis, it is extremely relevant to evaluate the possible mutagenic effect and the influence of the acetyl acetate extract from the leaves of B. dracunculifolia (EAE-Bd) on the frequency of the chromosomal damage induced by the chemotherapy drug doxorubicin (DXR) in mammalian cells both in vivo and in vitro. To this end, we carried out experiments on cells from the bone marrow and the peripheral blood of Wistar rats. Parameters such as the frequency of micronucleated polychromatic erythrocytes (MNPCEs) and the nuclear division index (NDI) were analyzed. Cell cultures from the Chinese hamster ovary were employed as test systems, and the frequency of chromosomal aberrations (CA) and the mitotic index (MI) were analyzed. The MNPCE frequencies revealed no significant difference between the animals treated with the EAE-Bd different concentrations (6; 12 and 24 mg/kg b.w.) compared to the negative and solvent controls groups, in the case of both the bone marrow and the peripheral blood, demonstrating the absence of EAE-Bd mutagenic effect in the above-mentioned dosages. Results also showed a significant reduction in the micronuclei frequency in the groups treated with EAE-Bd and DXR compared to those treated with DXR only. As for the NDI values obtained from the bone marrow and the peripheral blood of the animals submitted to the various treatments, they did not give evidence of any cytotoxicity. The in vitro studies demonstrated that the cultures treated with EAE-Bd different concentrations (12.5; 25 and 50 µg/mL) presented CA frequencies similar to those of the negative control. However, there was a significant increase in the CA frequency at the concentration of 100 µg/mL compared to the untreated cultures. Treatments with EAE-Bd and DXR revealed that cultures treated with 12.5 µg/mL EAE-Bd and DXR underwent a significant reduction in the CA frequency compared to the cultures treated with DXR only. The MI analysis showed that there were no significant differences between the cultures treated with different EAE-Bd concentrations and/ or DXR and the negative control, which accounts for lack of cytotoxicity. The components of B. dracunculifolia responsible for the mutagenic and antimutagenic effects observed in the present study are probably flavonoids and phenylpropanoids, since these compounds can act as pro-oxidants and free radical scavengers. Keywords: Baccharis dracunculifolia; Propolis; Micronuclei; Chromosomal Aberration