In-vitro Antibacterial Screening of Selected Folklore Indian Medicinal Plants with few Clinical Pathogens

Antibacterial activities of 7 plant extracts were evaluated against 5 bacterial strains using well diffusion assay at different concentration (10%, 20% and 30%) and the results were compared with therapeutically used antibiotics. Rapid formation of inhibition zones within 24 hours of incubation was obtained with ethanolic extracts (30%) of Justicia gendarussa against all tested strains. Ethanol extracts (30%) of the Gymnema sylvestre produces a maximum inhibition zone of 24mm against Pseudomonas aeruginosa which are known to be multi-resistant to drugs, while the standard values lies behind 17mm. Cluster analysis was applied to find out the similar groups of solvent extracts in their antibacterial action. Ethanolic plant extracts figured a separate cluster with the high antibacterial activity. Significant correlations were observed between the extract concentrations and antibacterial activity (P > 0.01).