Effectiveness of isolated oil from Aloe barbadensis Miller and its formulated ointment against selected pathogens

Background: Ethnomedicinally, the family Liliaceae is prominent in controlling skin, wound and fungal infections. The current work aimed at isolating a greenish oily substance from hexane fraction of Aloe barbadensis Miller leaf ethanol extract, and evaluating the antibacterial and antifungal potential of the pure compound and its polyethylene glycol formulated ointment. Methods: The column chromatography was used for the isolation of the oil from ethyl acetate-n-hexane solvent polarity. The characterization of the isolated compound was performed by spectroscopy techniques like UV, IR, 1H and 13C NMR spectroscopy. It was formulated as ointment using polyethylene glycol and both the ointment and the pure compound were investigated for their antibacterial and antifungal activities. Results: Pure compound has been isolated and the structure has been elucidated as hexadecanoic acid;(9Z,12Z)-octadeca-9,12-dienoic acid; octadecanoic acid;(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid;(Z)-octadec-9-enoic acid. Both pure compound and its polyethylene glycol formulated ointment exhibited growth inhibitory activities against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Klebseilla pneumoniae, Candida albicans and Talaromyces flavus. Minimum inhibitory concentration (MIC) values were found to be appreciably low, ranging between 0.32 mg/ml and 2.5 mg/ml. The formulated ointment displayed substantial inhibitory activities against all six pathogens compared to the unformulated compound. The MIC values ranged between 0.08 mg/g and 1.25 mg/g. Conclusion: The antimicrobial activity studies revealed that, both the pure compound and the formulated ointment have the potential to target multi-resistant microorganisms.