Antimicrobial potential of Terminalia chebula Retz. fruit extracts against ear pathogens

AIM: To evaluate the antimicrobial potential of Terminalia chebula(T. chebula) extracts against pathogens causing otitis externa and compare it with ear drops.METHODS: Four different extracts, methanol, ethanol,acetone and aqueous(hot and cold) extracts, from the T. chebula were tested for their antimicrobial activity through the agar well diffusion method and minimum inhibitory concentration(MIC)/minimum bactericidal concentration(MBC) values were determined through the macrodilution broth method against six different microorganism, five bacterial(one gram positive and four gram negative) and one yeast.RESULTS: Organic and aqueous fruit extracts displayed activity against all five tested bacterial ear pathogens with a maximum zone of inhibition of 31.6 mm against Staphylococcus aureus, followed by Acinetobacter sp.(24.6 mm), Pseudomonas aeruginosa(23.6 mm),Proteus mirabilis(21 mm) and Escherichia coli(19.3mm). Of the four solvents evaluated, acetonic fruit extract of T. chebula was found to be best. The MIC values ranged between 0.78 mg/m L and 50 mg/m L for the different bacterial ear pathogens and MBC values ranged between 1.56 mg/m L and 50 mg/m L. The acetonic fruit extract showed larger inhibition zones compared to the herbal ear drops, Kan pip with lowest MIC of 0.78 mg/m L and MBC of 1.56 mg/m L.CONCLUSION: Acetonic extract of T. chebula fruit may be used to treat otitis externa. However, more detailed studies, such as in vivo testing and pharmacokinetics properties, are needed to determine its therapeutic potential.