Abstract

The antibacterial activity of aqueous extract of Garcinia kola, honey and mixture of aqueous G. kola extract and honey was investigated against Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Bacillus subtilis, Salmonella sp. and Pseudomonas aeruginosa using agar well diffusion method. Sensitivity pattern of these bacteria was varied and extract concentration-dependent. It was observed that the synergistic use of aqueous G. kola extract and honey mixture was more effective in inhibiting bacterial growth than the separate use of aqueous G. kola extract and honey. The susceptibility of the test bacteria to the aqueous G. kola extract and honey mixture was in descending order as follows: P. aeruginosa > E. coli > S. aureus > Salmonella > K. pneumonia > B subtilis (> = more susceptible). Aqueous G. kola extract was most active against P. aeruginosa with zones of inhibition ranging from 16.7 ± 0.21 to 18.00 ± 1.00 mm and least active against B. subtilis with zone of inhibition of 0.00 - 6.00 ± 1.00 mm. Honey at 100% concentration inhibited growth of all the test organisms except B. subtilis. Statistical analysis showed that E. coli, S. aureus and P. aeruginosa at P < 0.05, exhibited significant difference in their susceptibility to the synergistic mixture and separate use of aqueous G. kola extract and honey. Synergistic use of aqueous G. kola extract and honey is therefore recommended as a better option than their separate use in the treatment of infections caused by the test bacteria.

Key words: Garcinia kola, honey, bacteria, antimicrobial activity, synergy