EVALUATION OF THE ANALGESIC ACTIVITY OF ETHANOL LEAF EXTRACT OF GMELINA ARBOREA IN HOT PLATE INDUCED PAIN MODEL IN MICE

Pain remains a major clinical problem and many communities rely on medicinal plants for analgesia. This study evaluated the analgesic properties of the ethanol leaf extract of Gmelina arborea in laboratory mice. Maceration method was done on the leaves using ethanol as solvent; the extract was subjected to phytochemical screening and an acute toxicity (LD₅₀) study. Analgesic activity was assessed using thermal (hot-plate) models. Treatment groups received graded doses of the extract (hot-plate: 1100,500,200 mg/kg) while Pentazocine (10 mg/kg) and normal saline served as positive and negative controls respectively. Phytochemical screening revealed the presence of flavonoids, saponins, tannins, alkaloids and steroids. Acute toxicity testing indicated an LD₅₀ of approximately 3808 mg/kg, suggesting low acute toxicity. The extract produced dose-dependent and statistically significant analgesic effects in the model, increasing latency on the hot-plate test the highest extract doses showed effects approaching those of Pentazocine, 1100mg/kg produces a latency of more 60mins compared to the 30 mins latency seen in 10mg/kg of the Pentazocine. These findings show some potential analgesic effect of the plant for relief of pain and suggest that its analgesic activity may be mediated by the central mechanisms. Isolation and characterization of the active constituents are recommended for future studies.