Avaliação das atividades antibióticas e antiparasitária de metabólitos secundários de fungos endofíticos da Anadenanthera macrocarpa.

Abstract

In the perspective of producing new drugs that are more effective than the existing ones, with the aid of biotechnology, researches with natural products and their derivatives have been an interesting alternative in the search for new medicines. An innovative source for this purpose are fungi, known for their environmental role, their versatility in obtaining secondary metabolites and the ease of reproducibility of results. In this sense, this work aims to analyze the inhibitory effect of the purified fractions of secondary metabolites of endophytic fungi of Anadenanthera macrocarpa, through antibiotic activity and in vitro analysis of antiparasitic action in Trypanosoma cruzi and Leishmania amazonensis. For this, plant samples were collected, endophytic fungi isolation, secondary metabolites production and purification by Reverse Phase in High Performance Liquid Chromatography (RP-HPLC) of the best inhibitors. The study of antibacterial activity was performed against Gram-negative, Escherichia coli and Gram-positive, Staphylococcus aureus, bacterial strains in order to identify the best antimicrobial producers. In vitro antiparasitic activity was evaluated against Trypanosoma cruzi strain Dm28c and the Leishmania Amazonian promastigote form. Of the 28 fungi obtained, the isolates of N° 8 and Nº20 were selected for purification by RP-HPLC, as they presented better antimicrobial activity against both bacteria. From this purification, the antibiogram test was again carried out on the same conditions, for both bacteria with the extract of Fungus Nº8; the antiparasitic test was performed with the extract of Fungus Nº20. The results revealed that all the fractions referring to the extract of Fungus Nº8, identified as Fusarium spp., against bacteria, had a broad spectrum action, with a mean inhibition of the fractions of 8,7mm for E. coli and 8.0mm of inhibition for S. aureus, and possibly the total extract shows a synergistic effect of several antibiotics. For the antiparasitic tests, Fractions 3 and 4 of the secondary metabolites of Fungus Nº20, identified as Aspergillus spp., reduced the viability of the Leishmania parasite caused by mitochondrial damage to more than 50%. Fraction 5 led to the death of 100% of the two parasites under study. Raising the possibility that some secondary metabolites of this fungus can be defined as antiparasitic.