ABSTRACT
The present work describes the in vitro biological activities of the crude extracts (petroleum ether, ethyl acetate and n-butanol) prepared from the species Ephedra altissima Desf. The estimation of total phenolic, flavonoid and tannin contents were carried out using the Folin-Ciocalteu, trichloroaluminum and acidified vanillin methods, respectively. The evaluation of the in vitro antioxidant activities were performed by three different methods namely: scavenging of the free radical ABTS, permanganate reducing antioxidant capacity, and potentiometric assay. In addition, the antibacterial activity was assessed by the agar disk diffusion assay against seven bacterial strains. The results of the phytochemical screening revealed the presence of several types of secondary metabolites. The EtOAc extract exhibited the highest content of phenols (125.62 ± 1.51 & 956;g EGA mg-1 of extract). The greatest flavonoid and tannin contents were observed for n-BuOH extract (19.18 ± 0.39 µg EQ mg-1 of extract and 8.95 ± 1.70 & 956;g EC mg-1 of extract, respectively). Moreover, the EtOAc extract revealed potent antioxidant activity in all the tested methods. Furthermore, the aqueous extract from the species E. altissima showed a good ability to reduce iron III to iron II with a value of 0.68 ± 0.3 moL eq L-1 in potentiometric assay. All the crude extracts (PE, EtOAc and n-BuOH) displayed inhibition of bacterial growth against at least three strains with values of MIC ranging from 3.125 to 50 µg mL-1. Therefore, these results suggest that Ephedra altissima could be used as an important source of natural bioactive compounds with antioxidant and antibacterial properties.
Subject(s)
Anti-Bacterial Agents , Antioxidants , Phytochemicals , Ephedra/immunology , Ephedra/microbiology , Ephedra/chemistryABSTRACT
Amostras de Ephedra tweediana Fisch & C.A. Meyer, coletadas de populações nativas da Reserva Biológica do Lami José Lutzenberger (Porto Alegre, RS, Brasil), e amostras de Ephedra triandra Tul., obtidas de plantas cultivadas em Porto Alegre/RS, foram extraídas com acetona, derivatizadas com ciclohexanona e analisadas por CG/EM. Para verificação da eficiência da metodologia, além das amostras de Ephedra tweediana e E. triandra, foram analisadas cinco amostras comerciais de Ephedra, de procedências distintas, cedidas por farmácias de manipulação locais. Os resultados encontrados indicam a ausência de efedrinas em Ephedra tweediana e E. triandra e presença de efedrina e/ou pseudoefedrina nas amostras comerciais.
Samples of Ephedra tweediana, collected from native populations occurring in the Reserva Biológica do Lami José Lutzenberger (Porto Alegre, RS, Brazil), and from cultivated plants of Ephedra triandra were submitted to extraction with acetone, derivatized with cyclohexanone and analyzed by GC/MS. In order to verify the efficiency of the methodology, besides Ephedra tweediana and E. triandra, samples of five commercial Ephedra extracts were analyzed, from distinct origins, get up from local drugstores. The results showed the absence of ephedrines in Ephedra tweediana and E. triandra, and the presence of ephedrine and/or pseudoephedrine in commercial samples.