Research Article
Francis Opoku and Osei Akot
Abstract
Alstonia boonei De wild is a major spice crop grown abundantly in Ghana and other tropical countries. In this study we have carried out phytochemical analysis and antimicrobial investigation of ethanol and aqueous extracts of the root of Alstonia boonei against a panel of clinically significant bacterial and fungal strains. Four Gram positive and Gram negative bacteria namely Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus were subjected to test the antimicrobial activity along with one fungi namely, Candida albicans. The ethanol and aqueous extracts of root of Alstonia boonei were subjected to microbial susceptibility assays using agar well diffusion method. Phytochemical screening was done to test the presence of phytochemicals responsible for the antimicrobial potential of roots of Alstonia boonei. The results of the phytochemical studies revealed the presence alkaloids, cyanogenetic glycosides, flavonoids, terpenoids and steroids and saponins. Susceptibility testing by disc diffusion assay revealed significant antimicrobial activity of methanol and aqueous extracts of the roots against the pathogens tested. The minimum inhibitory concentrations (MIC) of the various extracts by Agar Dilution method ranged from 3.0 to 10.0 mg/ml. The ethanol extracts exhibited better antimicrobial activity than aqueous extract. The study findings provide supportive evidence for the use of Alstonia boonei in traditional medicines.