Analgesic and anti-inflammatory activities of ethyl acetate and butanol fractions from Vitex polygama hydroalcoholic leaf extract

This study evaluated the analgesic and anti-inflammatory activities of Vitex polygama. Ethyl acetate and butanol fractions (10-30 mg/kg), obtained from the hydroalcoholic leaf extract, showed an antinociceptive effect in the acetic acid-induced abdominal writhing test, formalin test and modified hot plate test in mice, indicating a peripheral anti-inflammatory action. Ethyl acetate and butanol fractions were effective in inhibiting nitric oxide and TNF-α production, respectively, in RAW 264.7 macrophages. Both fractions (10-30 mg/kg) showed an acute analgesic effect in mice with vincristine-induced neuropathic pain exposed to a thermal stimulus. Through ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-UV-MS/MS) it was possible to identify seven major compounds: isoorientin, orientin, vitexin, isovitexin, O-p-hydroxybenzoyl orientin, O-caffeoyl-orientin, and di-caffeoylquinic acid. Orientin and isoorientin were isolated from ethyl acetate fraction and had their identity confirmed by nuclear magnetic resonance (NMR). Glucosyl flavones appear to be the main metabolites responsible for the anti-inflammatory and analgesic activities observed for V. polygama.