Carson C F, Riley T V
Department of Microbiology, University of Western Australia, Queen Elizabeth II Medical Centre, Nedlands.
J Appl Bacteriol. 1995 Mar;78(3):264-9. doi: 10.1111/j.1365-2672.1995.tb05025.x.
Tea tree oil, or the essential oil of Melaleuca alternifolia, is becoming increasingly popular as a naturally occurring antimicrobial agent. The antimicrobial activity of eight components of tea tree oil was evaluated using disc diffusion and broth microdilution methods. Attempts were also made to overcome methodological problems encountered with testing compounds which have limited solubility in aqueous media. After assessing media with and without solubilizing agents, the disc diffusion method was used to determine the susceptibility of a range of micro-organisms to 1,8-cineole, 1-terpinen-4-ol, rho-cymene, linalool, alpha-terpinene, gamma-terpinene, alpha-terpineol and terpinolene. While the disc diffusion method lacked reproducibility, it was considered useful as a procedure for screening for antimicrobial activity. Terpinen-4-ol was active against all the test organisms while rho-cymene demonstrated no antimicrobial activity. Linalool and alpha-terpineol were active against all organisms with the exception of Pseudomonas aeruginosa. Minimum inhibitory and minimum cidal concentrations of each component against Candida albicans, Escherichia coli and Staphylococcus aureus were determined using a broth microdilution method. Modifications to this method overcame solubility and turbidity problems associated with the oil components and allowed the antimicrobial activity of each of the components to be quantified reproducibly. There was reasonable agreement between minimum inhibitory concentrations and zones of inhibition. These results may have significant implications for the future development of tea tree oil as an antimicrobial agent.
茶树油，即互叶白千层的精油，作为一种天然抗菌剂正变得越来越受欢迎。采用纸片扩散法和肉汤微量稀释法对茶树油的八种成分的抗菌活性进行了评估。还尝试克服在测试在水性介质中溶解度有限的化合物时遇到的方法学问题。在评估了添加和不添加增溶剂的培养基后，使用纸片扩散法来测定一系列微生物对1,8-桉叶素、1-萜品醇-4、对伞花烃、芳樟醇、α-萜品烯、γ-萜品烯、α-松油醇和萜品油烯的敏感性。虽然纸片扩散法缺乏可重复性，但它被认为是一种筛选抗菌活性的有用方法。萜品醇-4对所有测试微生物都有活性，而对伞花烃没有抗菌活性。芳樟醇和α-松油醇对除铜绿假单胞菌外的所有微生物都有活性。使用肉汤微量稀释法测定了每种成分对白色念珠菌、大肠杆菌和金黄色葡萄球菌的最低抑菌浓度和最低杀菌浓度。对该方法的改进克服了与油成分相关的溶解度和浊度问题，并使得每种成分的抗菌活性能够被可重复地定量。最低抑菌浓度和抑菌圈之间存在合理的一致性。这些结果可能对茶树油作为抗菌剂的未来发展具有重要意义。
