The Ethanolic Stem-Bark Extract of Antrocaryon micraster Inhibits Carrageenan-Induced Pleurisy and Pedal Oedema in Murine Models of Inflammation

We investigated the antioxidant and anti-inflammatory effects of a 70% v/v ethanol extract of the stem bark of Antrocaryon micraster on murine models of carrageenan-induced pleurisy and paw oedema. Rat pleural fluid was analysed for volume, protein content, and leucocytes, while lung histology was assessed for damage. Lung tissue homogenates were assayed for glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and myeloperoxidase (MPO). Phytochemical analysis was carried out on the stem bark. Acute toxicity studies were conducted in rats. In the pleurisy model the extract (30-300 mg/kg) significantly reduced the volume and amount of proteins and leucocytes in the exudate and also protected against lung injury. Tissue level of GSH and SOD and CAT expression were increased while MDA level and MPO activity were reduced. The peak and total oedema responses were significantly suppressed when given both preemptively and curatively in the mice paw oedema test. Saponins, alkaloids, triterpenoids, and tannins were present in the stem bark. A. micraster extract exhibited no apparent acute toxicity. We conclude that the ethanolic stem-bark extract of A. micraster has antioxidant action and exhibits significant anti-inflammatory activity through suppression of pleurisy and paw oedema induced with carrageenan.