Chemical Composition and Antibacterial Activity of Essential Oil of Callistemon citrinus from Ethiopia

Abstract

Aims: The present study aimed to determine the chemical components and antibacterial activities of essential oil of the leaves of Callistemon citrinus collected from Ethiopia. Methodology: For identification and determination of the phytochemical constituents of the oil, Gas chromatography and Gas-chromatography/Mass-spectrometry analysis was carried out. Agar disc diffusion method was also employed to evaluate the antibacterial activities of the oil. Results: A total of fifteen phytochemical constituents were identified. The major constituents of the oil were found to be 1, 8-cineole (76.9%) and α-terpineol (15.3%) of the total composition. The In vitro antibacterial activity of the oil against Salmonella typhi, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa exhibited significant growth inhibition. The highest zone of inhibition was obsreved against Salmonella typhi (27.93±2.10 mm) followed by Staphylococcus aureus (23.83±2.75 mm) at tested dose of 50 mg/ml while the positive control Gentamycine at the same dose showed inhibition zone of (15.00±1.33 mm) and (13.25±1.25 mm) respectively.  Conclusion: Essential oil of Ethiopian Callistemon citrinus is reach of biologically active ingredients and posses potent antibacterial activities.