Evaluation of Medicinal Plants Extract against Biofilm Formation in Pseudomonas aeruginosa

The antibacterial and biofilm inhibitory activity of leaf extracts of Ocimum gratissimum, Moringa oleifera, Hibiscus sabdariffa, Azadirachta indica and seed extract of Garcinia kola against clinical isolates of Pseudomonas aeruginosa were evaluated using the agar diffusion and crystal violet assay methods. The ethanol extracts of O. gratissimum and H. sabdariffa exhibited significant antibacterial activity against the P. aeruginosa with diameter zones of inhibition of 25 mm and 30mm with minimum inhibitory concentrations (MIC) of 0.16 mg/ml and 0.18 mg/ml respectively. While the ethanol extracts of A. indica, M. oleifera and G. kola showed no antibacterial effect against the test organism. However, all five plants extract inhibited the formation of biofilm with optical density (OD) values reduction from 0.168 to 0.160 for O. gratissimum, 0.170 to 0.151 for H. sabdariffa, 0.140 to 0.138 for A. indica, 0.145 to 0.137 for M. oleifera and 0.135 to 0.130 for G. kola. Out of five plants extract tested, H. sabdariffa exhibited the best growth and biofilm inhibition activity of P. aeruginosa. The results of this study indicate that various concentrations of the plants extract particularly H. sabdariffa, may provide an alternative to control biofilm-related infections caused by P. aeruginosa.