Neurobehavioural and Analgesic Properties of Ethanol Bark Extract of Terminalia ivorensis A Chev. (Combrataceae) in Mice.

Abstract

Terminalia ivorensis A. Chev (Combretaceae) is a medicinal plant used in folk medicine in the management of pain, rheumatic condition, gastroenteritis and as a tranquilizer in psychotic disorder. We evaluated neurobehavioural and analgesic properties of the ethanol bark extract of T. ivorensis (EBETI). Effects of EBETI (1.25, 2.5, and 5 mg/kg) on novelty-induced behaviours were determined using open field test. Anxiolytic effect of EBETI (1.25, 2.5, and 5 mg/kg) was assessed using hole-board and elevated-plus maze paradigms. Analgesic property of EBETI (2.5, 5, and 10 mg/kg) was evaluated using acetic acid induced writhing, formalin and tail immersion tests. The extract was administered once intraperitoneally. The LD50 of EBETI was 173 mg/kg. EBETI (1.25, 2.5, and 5 mg/kg) significantly reduced rearing (142.3±1.6, 83.5±1.9, 39.3±1.5) and grooming (33.8±3.4, 28.4±3.0, 18.2±1.7) as compared with controls (180.5±4.9; 52.4±5.2). Treatment with EBETI (1.25, 2.5, and 5 mg/kg) significantly reduced head-dipping on hole-board (9.4±2.3, 6.2±1.9, 5.4±2.9) as compared with control (26.8±1.9). However, there was no anxiolytic effect on EPM. EBETI (2.5, 5, and 10 mg/kg) significantly inhibited abdominal constriction in writhing assay (21.8.0±2.4, 12.2±1.6, 5.8±2.1) as compared with control (35.0±1.7). Inhibition of neurogenic and inflammatory phases of formalin test was notice. However, the extract could not alter response to thermal stimulus in tail immersion test. EBETI is sedative and has analgesic effect, thus supporting its folkloric use in pain management and as a tranquilizer in psychosis.