Enhancement of the antibiotic activity of aminoglycosides by extracts from <i>Anadenanthera colubrine</i> (Vell.) Brenan var. <i>cebil</i> against multi-drug resistant bacteria

<p>The aim of this work was to evaluate the antimicrobial activity of ethanol (EEAC) and hexane (HFAC) extracts from the stem bark of <i>Anadenanthera colubrina</i> (Vell.) Brenan var. <i>cebil</i> alone or in combination with aminoglycosides against multi-drug resistant (MDR) bacteria. Minimal inhibitory concentrations (MICs) of the extracts were determined by using microdilution assay. For the evaluation of extracts as modulators of antibiotic resistance, MICs of neomycin and amikacin were determined in presence or absence of each compound at sub-inhibitory concentrations. Both EEAC and HFAC did not show antimicrobial activity against MDR strains tested. However, the addition of EEAC and HFAC enhanced the activity of neomycin and amikacin against <i>Staphylococcus aureus</i> SA10 strain. When the natural products were replaced by chlorpromazine, the same effect was observed. <i>Anadenanthera colubrine</i> var. <i>cebil</i> may be a source of phytochemicals able to potentiate the aminoglycoside activity against MDR <i>S. aureus</i> by the inhibition of efflux pump.</p

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora