Estudo da composição química e atividade anti-inflamatória da fração diclorometânica e subfrações de partes aéreas de Echinodorus grandiflorus (Cham. & Schltd. Micheli)

Abstract

Echinodorus grandiflorus (Cham. & Schltdl.) Micheli, popularly known as chapéu de couro in Brazil, is a plant species traditionally used to treat inflammatory diseases such as arthritis and gout. The main goal of this study was to evaluate in vitro the effect of E. grandiflorus dichloromethane fraction and subfractions on the production of inflammatory mediators, as well as to investigate the chemical composition of the active fraction. The crude extract of E. grandiflorus aerial parts was dissolved in water (40 mg/mL) and partitioned with dichloromethane. This fraction was filtered over active charcoal / celite (2:1) by eluting with methanol, acetone, dichloromethane and nhexane. The methanol and acetone sub-fractions are further fractionated by silica gel column chromatography eluted with dichloromethane / ethyl acetate / methanol in different proportions. The effect of the fractions were evaluated in vitro on LPSstimulated THP-1 cells. And the dexamethasone (0,1 µM/per well) was employed as positive control. Among the assayed fractions, dichloromethane fraction reduced more significantly the release of both mediators by LPS-stimulated THP-1 cells and showed no cytotoxicity at all tested concentrations (10, 30, and 90 µg/mL). Fractionation of methanolic sub-fraction by silica gel column chromatography afforded the sub-fraction 63-66, which tested at 10 µg/mL and 30 µg/mL elicited similar inhibition of TNF-α; and IL-1β release. The chemical composition of sub-fraction 63-66 was investigated by spectroscopy analyses (IR, GC-MS, UPLC-MS-MS and NMR) and allowed the identification of palmitic acid (C16H32O2) as its main constituent. Our findings point out Echinodorus grandiflorus as a source of bioactive compounds potentially useful to treat inflammatory diseases.