10 mg/ml 5 mg/ml 2.5 mg/ml Ciprofloxacin Staphylococcus aureus 7 6 4 40 Bacillus subtilis 7 5 3 23 Candida 8 6 5 N.A. Pseudomonas aeruginosa 5 4 7 35 Escherichia coli 5 4 7 37

Table 3: Antimicrobial activity of aqueous root extract of Alstonia boonei