ABSTRACT
The study evaluated the phytochemical constituents, elemental analysis, antioxidant and antimicrobial properties of Ethyl acetate extract of Alstonia boonei stem bark, a major spice crop that is grown abundantly in tropical countries. Phytochemical screening, elemental analysis, antioxidant and antimicrobial studies were completed using established methods. Phytochemical screening was done to test the presence of phytochemicals responsible for the antimicrobial potential of the stem bark of A. boonei. The results of the phytochemical studies revealed the presence of eugenols, steroids, phenolics, alkaloids and reducing sugar. Elemental analysis revealed the quantity of sodium 9.36 mg/kg, potassium 113.64 mg/kg, calcium 28.30 mg/kg, magnesium 2.10 mg/kg, copper 0.02 mg/kg, iron 6.36 mg/kg and zinc 2.4 mg/kg present in the stem bark. The in vitro antioxidant potential was examined using 1,1-diphenyl1-2-picrylhydrazyl (DPPH), free radical scavenging assay concentrations of 250,200,150,100 and 50 ug/ml had stem bark UV spectrometer and the control read 1.550 and IC50 at 13.9 ug/ml and 2.52 ug/ml for the extract and standard respectively. The stem bark extract showed antimicrobial activities with zones of inhibition ranging from 19-30 mm, minimum inhibitory concentration (MIC) of between 12.5 and 50 mg/ml. P. aeruginosa, K. pneumoniae, E. colli, S. aureus all have minimum bactericidal concentration (MBC) between 12.5 and 50 mg/ml, while B. subtilis above 50 mg/ml. The results consequently give a helpful clarification to the conventional medicinal use of the stem bark extract.
