Isolation and characterization of anti-inflammatory and analgesic compounds from Uapaca staudtii Pax (Phyllanthaceae) stem bark

Uapaca species including Uapacastaudtii Pax (Phyllanthaceae) are used in West Africa ethnomedicine to treat diverse ailments including pile, rheumatism, oedema and wound healing. However, the anti-inflammatory and analgesic potential as well as constituents of the Uapacastaudtii stem bark has not been investigated. The study was designed to evaluate the anti-inflammatory, analgesic, and antioxidant activities of extract and fractions ofU. staudtii stem bark, and to isolate the bioactive constituents. The anti-inflammatory, analgesic and antioxidant activities of the ethanol extract, dichloromethane, ethyl acetate, butanol, and aqueous fractions of U. staudtii stem bark, as well as protocatechuic acid and betulinic acid isolated from the bioactive ethyl acetate fraction were evaluated in different mice models of inflammation and pain; furthermore, antioxidant assays were carried out. Chemical structures of isolated compounds were established based on spectroscopic studies and comparison with literature data. The ethanol extract and ethyl acetate fraction exhibited good anti-inflammatory, analgesic, and antioxidant capacity in all studied models, comparable with those of the standard drugs used. Protocatechuic acid also gave significant (p