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Kunzea oil : investigation of composition, bioactivity and therapeitic potential
thesisposted on 2023-05-26, 03:06 authored by Thomas, J
For thousands of years natural products have had a prominent role in treating ailments. Among the plant-derived products used as medicinal agents, essential oils have been widely appreciated for their use as antimicrobial agents. Myrtaceous essential oils have also attracted industrial interest primarily due to their antimicrobial properties. Tea tree oil is the prominent contender. Kunzea oil is a myrtaceous essential oil obtained from the shrub Kunzea ambigua (Smith) Druce 1917. K. ambigua, genus Kunzea, family Myrtaceae, is endemic to northeast Tasmania as well as the Furneaux Islands and eastern coastal regions of Victoria and southern New South Wales. Kunzea oil has been listed as a therapeutic substance by the Therapeutic Goods Administration in Australia for topical application for the treatment of various dermatological ailments (AUSTL 72143; 1996). Kunzea oil is currently used in aromatherapy, as a topical antiseptic and for the treatment of various bacterial-fungal skin infections, eczema and psoriasis in humans and pastern dermatitis in horses. The initial objective of the study was to examine the chemical composition, antimicrobial activity and the insect repellency potential of kunzea oil. The second phase of the study investigated the potential usefulness of kunzea oil for the treatment of onychomycosis and efficacy of formulations containing kunzea oil for the treatment of pastern dermatitis in horses, in randomised controlled trials. Investigation on the chemical composition of kunzea oils demonstrated differences between oils from different plants (Kunzea spp.) analysed in this study. The results from the repellency trial indicated that K. ambigua essential oil offers protection from biting mosquitoes similar to that afforded by citronella oil. Kunzea oil-based formulations may be suitable for use in areas of low mosquito activity by people who wish to avoid the use of synthetic repellents. Kunzea oil appears to possess potentially useful in vitro antimicrobial activity with some fractions having higher activity. However, more work is required to further establish the optimum antimicrobial potential of kunzea oil. Two of the randomised clinical trials demonstrated the potential clinical usefulness of kunzea oil based topical formulations to treat pastern dermatitis in horses and pedal fungal infections in humans. Results of the pilot in vivo investigations open several avenues for further work in the form of in vitro bioassays and randomised, controlled trials for the development of topical formulations as an addition to the current battery of topical modalities for the management of cutaneous infections in humans and animals.
Rights statementCopyright 2012 the Author. The author has asked that the thesis not be made available via our repository. Requests for the thesis may be made through your institution's document delivery service. Chapter 2 (An examination of the essential oils of Tasmanian Kunzea ambigua, other Kunzea spp. and commercial kunzea oil) appears to be the equivalent of a post print article. The Version of Record of this manuscript has been published and is available in Journal of Essential oil Research 2008> http://www.tandfonline.com/10.1080/10412905.2010.9700351 Chapter 4 appears to be the equivalent of pre-copyedited, author-produced PDF of an article accepted for publication in Journal of medical entomology following peer review. The version of record, Thomas, J., Webb, C. E., Narkowicz, C., Jacobson, G. A., Peterson, G. M., Davies, N. W., Russell, C. R. (2009) An evaluation of repellent properties of volatile extracts from the Australian native plant Kunzea ambigua against Aedes aegypti (L.) (Diptera: Culcidae), Journal of Medical Entomology, 46(6), 1387-1391, is available online at: https://jme.oxfordjournals.org/content/46/6/1387.abstract