Bioguided isolation of myricetin-3-O-β-galactopyranoside with antinociceptive activity from the aerial part of Davilla elliptica St.-Hil

Ethnopharmacological relevance: Davilla elliptica St.-Hil. (Dilleniaceae) is a medicinal plant traditionally used in Brazil to treat inflammatory processes, to relieve pain, as diuretic, gastro- and hepatoprotective agents. Aim of the study: To undertake the fractionation of the ethanolic extract from Davilla elliptica leaves guided by an antinociceptive assay. Materials and methods: The antinociceptive activity was evaluated through the formalin test in mice. Extract fractionation was performed by percolation through silica gel and partition between immiscible solvents, followed by successive column chromatography over Sephadex LH-20 and preparative RP-HPLC. Structure elucidation of the isolated compound was accomplished by spectroscopic data. Results: The EtOAc and MeOH fractions derived from the crude extract reduced significantly the licking time in the late phase of the formalin test. The bioguided fractionation of the MeOH fraction resulted in the isolation of myricetin-3-O-beta-galactopyranoside, which produced significant inhibition on nociception induced by formalin (ID50 = 0.26 mg/kg; p.o.). Conclusions: These results point out that myricetin-3-O-beta-galactopyranoside contributes for the antinociceptive effect of Davilla elliptica extract, a constituent considerably more potent than diclofenac, employed as reference drug. (C) 2013 Elsevier Ireland Ltd. All rights reserved.