Investigação das atividades antioxidante e antimicrobiana de duas espécies arbóreas ocorrentes no bioma caatinga

The caatinga biome is a unique Brazilian biome predominant in the Northeast of Brazil. This biome hosts an impressive floristic biodiversity with species rich in molecules bioactives. The aim of study was investigate the antioxidant and antimicrobial activities of tree species occurring in caatinga. The antioxidant activity crude extracts of stem bark of Leucaena leucocephala and Cnidoscolus quercifolius were performed evaluating the total phenolic content and antioxidant activity in vitro by the method of capture of free radicals: DPPH (1,1-radical diphenil-2-picrilhydrazil) and ABTS (2,2 ‘azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)). The antimicrobial activity those extracts were performed against strains of Enterococcus faecales (ATCC 29212), Streptococcus pneumoniae (ATCC 49619) e Staphylococcus aureus (ATCC 25923) by a diffusion assay in agar and determination of Minimum Inhibiory Concentration (MIC).  The levels of phenolics found in the L. leucocephala exhibited relevant quantities of polyphenols, which was not observed in the species C. quercifolius. We observed that a direct correlation exists between the amount of total phenolics and antioxidant activity the species tested. The species tested not has significant antimicrobial activity.