Abstract

Background: Ulcerative colitis is a chronic progressive inflammatory disease of the large intestine, that affects largely the rectum and extends proximally within the colon, producing non-transmural inflammation. Current therapeutic options have proven not sufficient in the induction and maintenance of complete remission. Hence, identification of novel agents is imperative. Xylopia aethiopica is used locally in the management of inflammatory conditions. The aim of this study was to investigate the effect of hydroethanolic extract of the dried fruit of Xylopia aethiopica (XAE) in acetic acid-induced ulcerative colitis. 

Methods: Sprague Dawley rats were randomly grouped. The disease and non-disease control rats received saline orally for 8 days, another group received sulphasalazine 500 mg kg^-1 and three other groups received 30, 100 or 300 mg kg^-1 of XAE. On the 4^th day, colitis was induced in all groups except in the non-disease control rats, by intrarectal administration of 1 ml 4%^v/_v acetic acid. Animals were sacrificed on day 8 and parameters such as microscopic and macroscopic colon damage, argyrophylic nucleolar organiser region (AgNOR) staining, haematology, mast cell proliferation, enzyme activity and lipid peroxidation assessed. 

Results: XAE at all concentrations significantly (P < 0.001) reduced microscopic and macroscopic colon damage by decreasing epithelial cell loss and granulomatous inflammation. Treatment with XAE at all doses significantly (P < 0.0001) inhibited AgNORs/nucleus ratio to levels comparable with the non-disease control and reduced mucosal mast cell infiltration. Treatment with XAE resulted in significant (P < 0.0001) increase in the activity of superoxide dismutase while the activity of myeloperoxidase and subsequent production of malondialdehyde were inhibited. 

Conclusion: These novel findings give scientific credence to the traditionally reported anti-inflammatory property of the hydroethanolic extract of the dried fruit of Xylopia aethiopica.