Antibacterial potential of some medicinal plants of the Cordillera Region, Philippines

Abstract

Since plants have been the source of a large percentage of prescription drugs, it is very important that the antimicrobial properties of medicinal plants be investigated because these plants could be a resource for new and alternative treatment for some common infectious diseases. Eleven medicinal plants of the Cordillera Region, in the Philippines were evaluated for their antimicrobial properties by the standard disc diffusion assay method using test bacterial organisms: Escherichia coli, Bacillus subtilis, Staphyloccocus aureus and Proteus vulgaris, while test fungal organisms used were Candida albicans and Aspergillus flavus. Only four plants namely, Agathis dammara , Eupatorium triplenerve, Citrus aurantifolia and Tithonia diversifolia were found to have antibacterial properties. The Minimum Inhibitory Concentrations (MICs) of these plant extracts against the four test organisms were also determined. Results of MIC determination revealed that the gram positive organisms, Bacillus subtilis and Staphylococcus aureus, were more sensitive to the four plant extracts, since they scored the lowest value of MIC which ranged from 62.5 to 125 µg/ml. The gram negative organisms Escherichia coli and Proteus vulgaris scored higher MIC values ranging from 62.5 - 250 µg/ml. Phytochemical screening of the four plants with antibacterial activities were also undertaken.