MEDICINAL PLANTS FROM BRAZILIAN CAATINGA: ANTIBIOFILM AND ANTIBACTERIAL ACTIVITIES AGAINST Pseudomonas aeruginosa

Abstract

The Caatinga biome covers a vast area in northeastern Brazil and presents a high level of biodiversity. It is known that about 400 plant species are used by semi-arid local communities for medical purposes. Based on ethnopharmacological reports, this study aims to screen 24 species from Caatinga regarding the ability to prevent biofilm formation and to inhibit the growth of Pseudomonas aeruginosa - a major opportunistic human pathogen and an important causative agent of morbidity and mortality. The effects of aqueous extracts, at 0.4 and 4.0 mg mL-1, on biofilm formation and on growth of P. aeruginosa ATCC 27853 were studied using the crystal violet assay and the OD600 absorbance, respectively. The most active extracts were analyzed by thinlayer chromatography and high performance liquid chromatography. Our investigation pointed extracts of four species with potential application for the control of P. aeruginosa: Anadenanthera colubrina (Vell.) Brenan, Commiphora leptophloeos (Mart.) J.B. Gillett, Myracrodruoun urundeuva Allemão, whose antibiofilm effects (89%, 56% and 79% inhibition of biofilm, respectively) were associated with complete inhibition of bacterial growth, and Pityrocarpa moniliformis (Benth.) Luckow & R.W. Jobson, which were able avoid 68% of biofilm formation and inhibited 30% bacterial growth. The qualitative phytochemical analyses reveal the complexity of the samples as well as the presence of compounds with high molecular weight.