ABSTRACT

This study is about the isolation, characterization and anti-inflammatory activity of the secondary metabolites of the stem bark of Allophylus africanus Beauv (Sapindaceae). The plant has a wide distribution in West Africa, with Nigeria (Mambila Plateau, Calabar) inclusive. It has been used in communities for both its medicinal and economic importance. The stem bark of Allophylus Africanus was extracted by percolation using chloroform as solvent and allowed to concentrate by evaporation at room temperature. TLC was carried out after column chromatography and an Rf value of 0.87 was obtained at a solvent mixture of hexane: chloroform at ratio 1:4 from the finger column chromatography carried out on fraction AF3. Characterization using spectra analysis which include FT-IR, ¹H-NMR, ¹³C-NMR, H-H COSY, H-C COSY, 135 DEPT and Mass Spectra of A. africanus stem bark extract AF3 led to the elucidation of the structure of the proposed compound and proffer scientific basis for its use in the treatment of inflammatory disorders. FT-IR spectrum indicated that the compound could be an aromatic derivative with C-C stretching found at frequency 1465. Aromatic protons were seen at the chemical shift values of 7.25 ppm and Olefinic protons at 5.124 ppm, 5.146 ppm and 6.162 ppm appeared as doublets of doublets of doublets. COSY suggested the presence of –C=C-O-CH₂-OCH₂- moiety. Phytochemical screening revealed a predominance of tannins, saponins, flavonoids and alkaloids with little glycoside and no terpenes and steroid seen in the stem bark of A. africanus. The anti-inflammatory potency of the stem bark of Allophylus africanus P. Beauv were determined in vivo for suppressive and curative activities in rats using different doses of the extract (300 mg/kg & 600 mg/kg). The A. africanus extracts significantly reduced the increase in paw diameter induced by carrageenan at all doses (300 mg/kg & 600 mg/kg) as against normal saline treated group. The results suggest that the extract possesses considerable anti-inflammatory activity this shows that the plant possesses considerable therapeutic potential and thus provides some scientific basis for the traditional use of the stem bark in the treatment of inflammation and inflammatory disorders.