Caracterização química e investigação das atividades antibacteriana e anti-inflamatória tópica de Vernonia polyanthes LESS. (Asteraceae)

Abstract

Vernonia polyanthes Less., known as assa-peixe, is a vegetable specie that has been used in traditional medicine as anti-inflammatory, healing and antimicrobial. The aim of the present study was to chemically characterize and to investigate the antioxidant, antibacterial and topical anti-inflammatory activities of Vernonia polyanthes Less. Dried and powdered leaves were exhaustively extracted with hexane, ethyl acetate and ethanol by static maceration. The quantification of total phenols and flavonoids contents were determined by spectrophotometry. The antioxidant activity was measured by DPPH (2, 2-diphenyl-1-picrylhydrazyl), ferric reducing power and -carotene bleaching. The antibacterial activity was established by diffusion method agar and the Minimum Inhibitory Concentration was determined through the broth microdiluition method. The chemical characterization was conducted by High Performance Liquid Chromatography and by Gas Chromatography / Mass Spectrometry. The topical anti-inflammatory activity was investigated using the ear edema assay induced by croton oil and arachidonic acid. Data were expressed as mean ± standard and analysis of variance followed by Newman-Keuls test or Tukey was measured the significance level (p 0.05). The total phenolic and flavonoids values ranged from 0.53 to 22.93 g / 100 g and 0.18 to 8.23 g / 100 g, respectively. The extracts in ethyl acetate and ethanol showed antioxidant activity using the applied methods. All extracts (hexane, ethyl acetate and ethanol) inhibited the growth of the reference bacteria tested, variably. The High Performance Liquid Chromatography detected the constituents in the extracts as follows: 1) hexane: luteolin; 2) ethyl acetate: luteolin, apigenin and rutin; and 3) ethanol: luteolin and rutin. The Gas Chromatography / Mass Spectrometry also detected the presence of -amyrin and two triterpenes ursolic acid derivatives in the hexane extract. The extracts of Vernonia polyanthes Less. leaves inhibited the ear edema induced by phlogistic agents tested, demonstrating topical anti-inflammatory. The results indicated that Vernonia polyanthes Less. is a source of bioactive substances, presents antioxidant, antibacterial, and topical antiinflammatory activities, and can be use as an promissing alternative for therapeutic aplications