Estudo das propriedades imunomodulatórias do extrato bruto hidroalcólico das partes aéreas de Baccharis dracunculifolia DC. (Asteraceae)

Abstract

Introduction: Plant species have been target of studies due to their therapeutical potential, since they produce bioactive secondary metabolites. Baccharis dracunculifolia DC. (Asteraceae) has been recognized as the main source of Brazilian green propolis and is popularly known as “alecrim do campo” or “vassoura”. It is used in Brazilian folk medicine as anti-inflammatory. This study aimed to evaluate the immunomodulatory properties of the crude hydroalcoholic extract of B. dracunculifolia on the production of immune mediators, and its mechanisms in peritoneal macrophages and splenocytes. Methods: The leaves from B. dracunculifolia were collected and the extract was obtained with ethanol: water (8:2, v/v). The extract was analyzed by high performance liquid chromatography (HPLC). For biological assays C57Bl/6 mice were utilized. Citotoxicity was evaluated both in macrophages and splenocytes using MTT method. Proliferation of splenocytes assay was also performed by MTT. Peritoneal macrophages and splenocytes from C57Bl/6 mice were cultured for NO production, which was performed by Griess method and CD80, CD86, CD40 and MHC II expression analysis were evaluated in macrophages culture by flow citometry. The cytokine (IL-12) production assay was performed by ELISA. Results: 120g of the crude extract E-Bd were obtained and it was not cytotoxic on macrophages and splenocytes culture in concentrations up to 100 g/mL. The proliferation of splenocytes was inhibited. E-Bd extract was able to reduce NO levels on both cell cultures. Results obtained by flow cytometry indicated that E-Bd reduced the expression of CD80 and CD86 co-stimulatory molecules and also CD40 but not of MHC II. Furthermore, IL-12 production was also reduced in the presence of E-Bd extract. Conclusion: The presented results suggest that E-Bd can modulate immune responses.