Avaliação in vitro da atividade biológica de Zornia reticulata Sm. (FABACEAE)

Abstract

Plants are an important source of biologically active natural products. Knowledge about its therapeutic properties, derived from the popular therapy and usage, motivates much of the research on its pharmacological activities used in the treatment of various infectious diseases mainly. The discovery of the first antibiotic revolutionized the treatment of infections decreasing their mortality. However, concurrently with the clinical application of the first generations of antimicrobials, microbial resistance emerged. In addition to the antimicrobial activity of metabolites extracted from plants, a new concept in the use of these products has been studied, which is the combination of conventional antimicrobial agents, as a resistance modifier agent. Zornia reticulata Sm. (Fabaceae) known as Urinana, is a plant located in most parts of Brazil, is used in folk medicine to treat infections, particularly urinary disorders, a fact that suggested his name. The objetive of this study was to evaluate the in vitro antibacterial activity and modulating the resistance against the gram positive and gram negative strains, the Hemolyzing potential, antioxidant activity, perform the phytochemical prospecting and characterized by high-performance liquid chromatography (HPLC) of the extract and fractions of Z. reticulata. The sheets were dread, crushed, and the powder obtained was subjected ofliquid-liquid partition with ethanol, with subsequent solvent removal and fractionation with hexane, chloroform and ethyl acetate. Microdiluition tests were performed to verify the antibacterial and modulatory activity and MIC determination. The results showed that the extract and Z. reticulata fractions have antimicrobial activity against most tested strains. The most representative effect against the gram positive bacteria was the combination of cefepime with chloroform fraction with reduced MIC 31.25 μg.mL to 5.87 μg.mL-1. Front of Gram negative bacteria, the most significant combination was gentamicin the ethyl acetate fraction, wich reduced the gentamicin MICs of 5.0 to 0.3 μg.mL-1μg.mL-1 front of a P. aeruginosa multiresistant. The interaction between plant tissue and conventional antibiotics were 66% synergistic. It was observed that the ethyl acetate fraction showed the highest antioxidant activity, as well as the higher content of flavonoids and phenolic compounds, and the hexane fraction was found the highest amount of tannin. The chloroform fraction showed lower potential hemolyzing. The Z. reticulata components are still unknown because, by chromatographic analysis can say only that it is not possible to identify the presence of compounds: caffeic acid, gallic acid, kaempferol, catechin, rutin and quercetin.The data obtained suggest that the extract and fractions of Z. reticulata, may be an alternative in treatment of various infections. However, we need further testing intoxicity and vivo to better prove these claims.