In vitro evaluation of antioxidant, antimicrobial and toxicity properties of extracts of Schinopsis brasiliensis Engl. (Anacardiaceae)

Abstract

This study aimed to investigate the phenolic content, antioxidant capacity, the antibacterial and toxicological profile of the methanolic extract of Schinopsis brasiliensis Engl. (MExSb). The phenolic content was determined by Folin-Ciocalteu methodology and the flavonoids content by complexation with chloride aluminum. The antioxidant activity was evaluated by DPPH method. The antimicrobial activity was tested by agar diffusion method and the minimum inhibitory concentration (MIC) was determined. The toxicological profile was obtained using tests with larvae of Artemia salina Leach. High levels of phenolic compounds (825.65 ± 40.99 tannic acid equivalents in mg/g material) were found in MExSb, where 55 and 1.8% (in g/100 g dry weight of extract) of these corresponded to tannins and flavonoids, respectively. The MExSb showed high antioxidant capacity (EC50 8.80 ± 0.94 µg.mlˉ¹). Also a high antimicrobial activity was observed, particularly against strains of S. aureus and P. aeruginosa, with MIC of 125 and 62.5 µg.mlˉ¹, respectively. Finally, the MExSb showed moderate toxicity against A. salina. These findings allow concluding that the MExSb is a valuable source of molecules with antioxidant and antimicrobial capacity. Other studies, such as identification and quantification of major active components of MExSb are running and will evaluate the potential of the isolated compounds. Key words: Artemia salina, "baraúna", brine shrimp assay, DPPH, MIC, multidrug resistance, phenolic compounds.