Avaliação da atividade imunomodulatória in vitro do extrato bruto e de metabólitos secundários de Baccharis dracunculifolia (Asteraceae)

Abstract

Plants are used for over 60,000 years by humans through folk medicine. Baccharis dracunculifolia (Asteraceae) is a native species from Brazil that is being considered as the main botanical source of green propolis, known for its antimicrobial, anti-inflammatory and immunomodulatory properties. Due to the scarcity of studies on the action of Baccharis dracunculifolia in the immune system, the present work had as main objective to evaluate the effects of the crude extract and fractions of B. dracunculifolia and their secondary metabolites on the production of inflammatory mediators in supernatant of cell cultures of mice C57BL/6 splenocytes. Also sought to give the crude extract and fractions of its aerial parts, to perform the isolation, purification and identification of the major secondary metabolites present in B. dracunculifolia aerial parts and to evaluate the effects of the crude extract, organic fractions and secondary metabolites obtained from this plant species on the levels of IL-17, IL-4, TNF-α, IFN-γ cytokines (for ELISA) and nitric oxide (NO) (Griess method) in mice C57BL/6 splenocytes. The metabolites isolation was performed by chromatographic techniques which were identified by 1H NMR spectroscopy. In the spectra analysis, it was considering as a basis the data literature comparison, which allowed us to identify the structure of the acid (E)-4-(2,3- diidrocinamoiloxi) cinnamic, ermanina and beturetol. In tests for evaluating in vitro of immunomodulatory activity, it was concluded that NO has suffered inhibition of both the crude extract and the chloroform fraction in the two highest concentrations tested (100 μg/mL e 50 μg/mL). By another, the hexane and the aqueous fractions were inhibited only at the highest concentration tested (100 mg / mL). The isolated metabolites were also able to inhibit NO production in concentration (100 mg / ml). The results of IL-4, IL17, INF- e TNF-α cytokines evaluation have showed that crude extract was able to inhibit the IL-4, IL-17 and TNF-α production in all of three concentrations that were tested (100 μg/mL; 50 μg/mL; 25 μg/mL) and IFN-in the two highest tested concentrations (100 μg/mL; 50 μg/mL). The chloroform fraction has inhibited IL-4, IFN- e TNF-α production in three concentrations tested (100 μg/mL; 50 μg/mL; 25 μg/mL) and IL-17 only at the highest concentration (100 μg/mL). The hexane fraction was able to inhibit all cytokines only at the highest concentration (100 mg / mL). Since the aqueous fraction has inhibited only IL-17 at the highest concentration (100 mg / mL). The (E) -4 - (2,3-diidrocinamoiloxi) cinnamic substance has proved to be active at the two highest concentrations in the presence of IL-4, IFN- and TNF-α. Now, the beturetol substance has inhibited IL-4 and IL-17 (100 mg / mL, 50 mg / ml) and IFN-γ and TNF-α (100 g / ml) production. The ermanina substance has inhibited IL-4 and IFN-γ production only at the highest concentration tested (100 mg / mL). The chloroform fraction has showed to be the most active of the tested ones. It was concluded that the study demonstrated the immunomodulatory effect of the specie analyzed against inflammatory mediators and further studies should be conducted to elucidate Baccharis dracunculifolia immunomodulatory potential.