Comparative study on phyto-constituents, antioxidants and biological activity of Daniellia oliveri leaf and stem bark extracts.

Abstract

Daniellia oliveri is an ethnomedicinal plant traditionally used for the management of several health conditions. This study comparatively evaluated the phytochemical composition, anti-nutritional factors, antioxidant, anthelmintic and antiemetic activities of methanol and n-hexane extracts of the leaves and stem bark of Daniellia oliveri. Leaf and stem bark samples were extracted separately with methanol and n-hexane and evaluated using standard phytochemical, antioxidant, anthelmintic and antiemetic assays. The methanol stem bark extract contained the highest concentrations of total phenolics (161.12 mg GAE/g), flavonoids (51.05 mg QE/g), tannins (20.15 mg CE/g), and saponins (36.96 mg DE/g). In contrast, alkaloids were highest in the n-hexane leaf extract (10.07 %). In the DPPH assay, MS exhibited the lowest IC₅₀ among the extracts (194.98), whereas the n-hexane leaf extract had the highest IC₅₀ (588.84); vitamin C showed an IC₅₀ of 64.57. In the in-vitro anthelmintic assay, the methanol leaf extract produced the shortest paralysis time among the plant extracts, with 15.55 min at 50 mg/mL, compared with 12.50 min for piperazine citrate at 10 mg/mL. In the chick antiemetic model, the n-hexane stem bark extract produced 60.25 % inhibition of retching at 150 mg/kg, followed by the methanol stem bark extract (52.32 %). These findings demonstrate that the biological activities of Daniellia oliveri vary according to plant part and extraction solvent. The results provide preliminary experimental evidence supporting further investigation of Daniellia oliveri as a source of bioactive constituents with antioxidant, anthelmintic and antiemetic potential. However, identification of the active compounds, mechanistic studies, comprehensive toxicity evaluation and pharmacological validation are required before therapeutic applications can be proposed.