Antinociceptive Activities and Phytoconstituents of Aqueous Leaf Extract of Polyalthia longifolia (Sonn.) Thwaites

Abstract

The study was aimed at evaluating the antinociceptive activities and phytochemical constituents of aqueous leaf extract of Polyalthia longifolia (Sonn.) Thwaites. Both hot plate nociception and acetic acid-induced writhing reflex models were used to measure the ability of the extract to inhibit painful impulses, while secondary metabolites contained in the extract were determined by qualitative screening tests. The extract, at all doses, provided significant antinociceptive activity (P< 0.05) against thermally-induced pain stimulus at a temperature of 55±1 0C. The number of writhes, 56.5±0.90, 55.0±0.58 and 32.75±0.48 due to 100, 200 and 800 mg/kg treatments respectively, were significantly reduced (P< 0.05) compared to the value, 71.20±1.04, recorded in the control group. The activity of the extract appears to be mediated by both central and peripheral routes. Alkaloids, flavonoids, saponins and phenols confirmed in the extract may be responsible for the activities of the extract.
Keywords: Antinociceptive; Phytochemistry; Leaf; Extract; Polyalthia longifolia