Callistemon citrinus is a plant that is native to Australia. It is also known as Callistemon lanceolatus or Melalenca citrina. In South Africa, this plant is grown as an ornamental and invasive species. The aim of this study was to determine the anti-inflammatory effect of 3 concentrations (100, 200 and 400 mg/kg) of methanolic leaf extracts of C. lanceolatus on male Wistar rats. The experiments correlated significantly with the result of the diclofenac sodium which was used as the standard drug . The result of this study showed, in comparison to triplicate control samples, that the methanolic leaf extracts of Callistemon lanceolatus exhibited anti- inflammatory activities in Wistar rats. It was found that the 3 extracts inhibited the formation of large paw volumes over the 3 hour period, with an exception of the 100 mg/kg methanolic C. lanceolatus extract. In relation to the immunological responses, it was observed that the 3 extracts inhibited the release of inflammatory and lipid mediators, histamine and prostaglandins via the mast cells in Wistar rats. There was less accumulation of body fluid in the plantar region of the rats, which were attributed to the anti-inflammatory effect of the 3 methanolic extracts.

Keywords: carrageanan, plantar, diclofenac sodium, odema, B-galactose, IgE, allergic reaction, prostaglandins, anti-inflammatory.