Antifungal activity of the components of Melaleuca alternifolia (tea tree) oil

Abstract

Aims: To investigate the in vitro antifungal activity of the components of Melaleuca alternifolia (tea tree) oil. Methods and Results: Activity was investigated by broth microdilution and macrodilution, and time kill methods.Components showing the most activity, with minimum inhibitory concentrations and minimum fungicidal concentrations of £0AE25%, were terpinen-4-ol, a-terpineol, linalool, a-pinene and b-pinene, followed by 1,8-cineole. The remaining components showed slightly less activity and had values ranging from 0AE5 to 2%, with the exception of b-myrcene which showed no detectable activity. Susceptibility data generated for several of the least watersoluble components were two or more dilutions lower by macrodilution, compared with microdilution. Conclusions: All tea tree oil components, except b-myrcene, had antifungal activity. The lack of activity reported for some components by microdilution may be due to these components becoming absorbed into the polystyrene of the microtitre tray. This indicates that plastics are unsuitable as assay vessels for tests with these or similar components. Significance and Impact of the Study: This study has identified that most components of tea tree oil have activity against a range of fungi. However, the measurement of antifungal activity may be significantly influenced by the test method.

The effect of tea tree oil and antifungal agents on a reporter for yeast cell integrity signalling

“…As suggested above, we therefore assume that all these components act on the yeast cells by interference with plasma membrane function, similar to chlorpromazine (Sikkema et al, 1995;Kamada et al, 1995). These data are consistent with previous reports on the fungicidal activity of TTO (Hammer et al, 2003). When tested in our reporter strain, we observed a clear dose-dependent increase in β-galactosidase activities, demonstrating for the first time an activation of cell integrity signalling by TTO.…”

Strong Induction of Minor Terpenes in Italian Cypress, Cupressus sempervirens, in Response to Infection by the Fungus Seiridium cardinale

“…The role of camphor (Kotan et al 2007;Marei et al 2012;Pragadheesh et al 2013;Ramsewak et al 2003) is ambiguous, being inhibitory for some fungi but not others, suggesting slight fungal toxicity. α-Terpineol, however, is a powerful fungal inhibitor ( Cakir et al 2004;Hammer et al 2003;Kossuth and Barnard 1983;Kotan et al 2007;Kusumoto et al 2014;Zhou et al 2014). Thymyl methyl ether is among the least inhibitive chemical structures of thymol to several fungi (Kumbhar and Dewang 2001).…”

Composition chimique et activités antibactériennes, antifongiques et antioxydante de l'huile essentielle dePelargonium asperumEhrh.exWilde des Comores

“…Les résultats de cette étude sont regroupés dans le tableau II. (Kurita et al, 1981 ;LisBalchin & Deans, 1996 ;Lalli et al, 2008), ce qui est aussi en accord avec les investigations de plusieurs auteurs qui ont montré que, pour les huiles essentielles de plusieurs plantes médicinales, les moisissures sont de loin plus sensibles que les bactéries (Pellecuer et al, 1973(Pellecuer et al, , 1974Benjilali et al, 1984 ;Kivanç & Ajgûl, 1986 ;Tantaoui-Elarki & Beraoud, 1994 ;Hammer et al, 2003). D'une façon générale, les activités antibactériennes et antifongiques de l'huile de géranium Bourbon peuvent être attribuées principalement aux alcools terpéniques (citronellol, géraniol, linalol) qui représentent environ 50,07% des constituants de cette huile.…”

“…Les feuilles persistantes sont un peu coriaces et couvertes de poils microscopiques parsemés de glandes qui libèrent leur parfum au toucher ou à la chaleur. Les fleurs roses maculées de pourpre et de grenat s'épanouissent tout au long de l'année et sont la plupart du temps stériles (Watt & Breyer-Brandwijk, 1962 ;Rajeswara et al, 1993Rajeswara et al, , 1994Kulkarni et al, 1997 ;Hammer et al, 2003). Idéalement, il croît dans des conditions climatiques et édaphiques ni humides ni trop sèches.…”