Estudo químico e avaliação do potencial bioativo dos metabólitos especiais de fungos endofíticos isolados das raízes de Combretum lanceolatum Pohl ex Eichler

Abstract

Entophytic fungus are promising sources and not very explored in the search for new bioactive metabolites. So, the objective of this work was to select entophytic fungi obtained from Combretum lanceolatum capable of producing extracts or bioactive substances with antimicrobial, antioxidant, antidepressant, and trypanocida is chistosomicidal. We evaluated eight species of fungi isolated from the roots of C. lanceolatum present in the Pantanal of Mato Grosso, namely: Cladosporium perangustum-95C, Diaporthe phaseolorum-92C, Fusarium oxysporum-33C Leptosphaerulina chartarum-72C, Macrophomina phaseolina-46C, Penicillium simplicissimum- 99C, Penicillium verruculosum-41C, Trichoderma spirale-66C. The qualitative antimicrobial activity assay has been used by disk diffusion against pathogenic bacteria Pseudomonas aeruginosa, Escherichia coli ESBL +, Gram-positive Staphylococcus aureus (ATCC 25923) and Gram negative: Escherichia coli (ATCC 25928). The antioxidant activity of the extracts was assessed by the method 2,2-Diphenyl-1-Picrilidrazila (DPPH). The antidepressant capacity of the extracts was assessed by immobility of the mice in the forced swimming test and held by the tail. The schistosomicidal potential was evaluated for mortality and decreased motor activity of adult Schistosoma mansoni worms. Cytotoxicity has been evaluated by checking the viability of lung fibroblasts, Chinese hamster cells (V79) by the XTT assay. Leishmanicidal activity was evaluated for viability of promastigotes of Leishmania amazonensis and the antitumor activity was evaluated for viability of MCF-7 tumor cells MDA-MB-231 (breast cancer), both by the method 3- [4,5-dimethylthiazol -2-yl] -2,5-diphenyltetrazolium bromide (MTT). All extracts showed inhibitory activity against pathogenic bacteria, with a region of inhibition ranged from 8 to 24 mm, and the isolated extract D. phaseolorum-92C showed the greatest inhibition zones, 23 and 24 mm against S. aureus (ATCC 25923) and E. coli (ATCC 25928), respectively. The results showed that 100% of the extracts possess low to moderate antioxidant activity. Extracts (EtOAc) of L. chartarum-72 and D. phaseolorum-92C showed the highest values for antioxidant activity. In the evaluation of antidepressant capacity, extract L. chartarum-72C has antidepressant effect type in mice both TNF and in TSC. In evaluating the potential schistosomicide, T. Spirale-66C extract killed 100% of the Schistosoma mansoni adult worms at a concentration of 50 µg/mL, at 24 hours. In the assessment of cytotoxicity, concentrations above 78,1 µg/mL F. oxysporum-33C extract and 312 µg/mL for T. spirale-66C extract and D. phaseolorum-92C, respectively, indicate be cytotoxic for V79 cells. The extract (EtOAc) of F. oxysporum-33C presented trypanocidal activity of 89% xi at a concentration of 40 µg/mL, the extracts (EtOAc) of D. phaseolorum-92C and T. spirale-66C reduced by 7% the amastigotes and trypomastigotes at concentrations of 10 and 80 µg/ml, respectively. Were isolated two substances by high performance liquid chromatography (HPLC), a statement (EtOAc) of F. oxysporum-33C (Fo-1 substance) and another D. phaseolorum-92C (Dp-1 substance). Except for the antimicrobial, test the substances showed satisfactory results in other bioassays. Dp-1 has been identified by spectroscopic methods, with 18-dehydroxy cytochalasin H, a derivative of Zigosporina and, the Fo-1 substance has not been clarified. The two isolated compounds showed a moderate antioxidant activity. The isolated (Dp-1) reduced the percentage of viability (27.49%) of promastigotes of L. amazonensis cells, while Fo-1 showed 35.53% viability at a dose of 50 mg/mL, respectively. In the evaluation of trypanocidal activity Dp-1 substance was reduced by 12% of amastigotes and trypomastigotes of T. cruzi forms. The percentage of the viable tumor cells ranged from 47 to 99%. The isolated material (SD-1) was more effective against tumor cells MDA-MB-231, as against the MCF-7 tumor cell decreased 77% viability at 30 µg/ml. The data show that endophytes extracts of C. lanceolatum produce metabolites with different bioactivities.