Antimicrobial Activity of Terminalia catappa L. Leaf Extracts against Some Clinically Important Pathogenic Microbial Strains

Objective: The present study was undertaken to evaluate in-vitro antimicrobial activity of methanol, acetone and N, N-dimethylformamide extracts from leaf of Terminalia catappa L. (Combretaceae). Methods: In vitro antimicrobial activity of all the extracts was done by agar disc diffusion assay. 91 clinically important strains were used for the study, which were both clinical isolates as well as identified strains. Piperacillin and gentamicin were used as standards for antibacterial assay, while nystatin and flucanazole were used as standards for antifungal assay. Antimicrobial activity was determined by measurement of inhibition zone around each paper disc. For each extract three replicate trials were conducted against each organism. Results: The antibacterial activity was more pronounced against bacteria than fungal strains. The Gram positive bacteria were more susceptible than Gram negative bacteria. The methanol extract showed best antibacterial activity. T. catappa leaf extracts showed better antibacterial activity than commercially used antibiotics. Conclusion: Demonstration of antimicrobial activity of T. catappa provides the scientific basis for the use of this plant in the traditional treatment of diseases and may help to discover new chemical classes of antibiotic substances that could serve as selective agents for infectious disease chemotherapy and control. This investigation has opened up the possibility of the use of this plant in drug development for human consumption possibly for the treatment of various infections caused by microbes.