Antimicrobial activities and preliminary phytochemical tests of crude extracts of important ethnopharmacological plants from Brazilian Cerrado

Abstract

Screening of native plants with therapeutical effects constitutes a valuable way to enhance biol. attributes of medicinal herbs and discover new drugs.Therefore, ethanol and methanol exts. from ten plants collected from Brazilian Cerrado were tested toinhibitory effects against Escherichia coli(ATCC 25922), Staphylococcus aureus(ATCC 25923) and Pseudomonas aeruginosa(ATCC 27853) through disk diffusion. The crude exts. that showed antibacterial activities from Anacardium humile, Psidium guineense and Myracrodruon urundeuva, were tested on the std. strain S. aureus ATCC 25923. The min. inhibitory concns. (MICs) and min. bactericidal concns. (MBCs) were detd. and the interactions between the plant exts. and the main groups of secondary compds. present were investigated. The MICs of P. guineense, M. urundeuva and A. humile were all 4.1 μg/L for S. aureus. P. guineense and A. humile exts. tested against P. aeruginosa were 8.2 μg/L, whereas the ext. from M. urundeuva had a MIC of 4.1 μg/L for the same strain. In addn., the obsd. MBCs were equiv. to the corresponding MICs. There were synergistic interactions in combinations of these plant exts. and tannins and flavonoids were identified in phytochem. analyses. These metabolites may be related to the biol. activities that were found, indicating possible candidates for the development of strategies for treatment of infections caused by bacteria tested. [on SciFinder(R)]