Avaliação da atividade biológica da Baraúna (Schinopsis brasiliensis Engl.)

Abstract

Plants have been used by humanity since ancient times to treat diseases. In this context, species Schinopsis brasiliensis Engl, an endemic semi-arid tree found in the Caatinga biome, is used by the population due to its anti-inflammatory properties. Studies have already demonstrated antimalarial, antifungal, antinociceptive, antiinflammatory, photoprotective, cytotoxic, larvicidal, antioxidant and antimicrobial activities of various parts of the plant, mainly from ethanolic, methanolic and essential oil extracts, but there are no records of studies with more purified fractions of these extracts. Thus, the present study aimed to evaluate the ethyl acetate fraction of S. brasiliensis to identify the classes of secondary metabolites present in it by phytochemical prospection, determinate the total phenol and flavonoids contents and its antioxidant and antimicrobial activities. The phytochemical prospection of the ethyl acetate fraction, using colorimetric and precipitation methods, revealed the presence alkaloid, anthocyanins, catechins, flavonoids, leucoanthocyanidins, saponins, tannins and triterpenoids. The content of total phenol and flavonoids, respectively, was 807.28 ± 0.002 mg EAG/g and 218.14 ± 0.01 mg EQ/g. As for the antioxidant activity by the DPPH method, an IAA of 4.3 ± 0.01 and IC50 of 9.49 ± 0.01 μg/mL were observed. In the analysis of the antimicrobial activity, it was observed the bacteria Streptococcus pyogenes and Klebsiella rhinoscleromatis were resistant to the ethyl acetate fraction, with halos of growth inhibition of 8mm. Bacteria Streptococcus agalactiae, Escherichia coli and E. coli derived showed an inhibition halo of 10 mm, thus being classified as having intermediate sensitivity, while Staphylococcus epidermidis had the largest inhibition halo of 20 mm, showing its high sensitivity to the fraction. As for the minimum inhibitory concentrations (MIC), S. epidermis did not grow in any of the tested concentrations, and its MIC was 1.68 μg.mL-1 . S. agalactiae, E. coli, E. coli derived and K. rhinoscleromatis had MICs of μg.mL-1 , while S. pyogenes showed the highest MIC value at 12.5 μg.mL-1 . Thus, the ethyl acetate fraction exhibited several secondary metabolites and showed antioxidant and antimicrobial activity, demonstrating its potential for future studies that evaluate its chemical composition in more detail, determining the compounds present in the fraction, as well as preclinical and eventually clinical studies on its properties.