Eucalyptus globulus Labill., E. polybractea F.Muell. ex R.T.Baker, E. smithii F.Muell. ex R.T.Baker, and other Eucalyptus spp.

Myrtaceae

Blue gum

Eucalypti aetheroleum (Eucalyptus oil); Eucalypti folium

Essential oil distilled from leaves; more rarely, leaves

The oil contains 1,8-cineole (eucalyptol) as the major component (>70%) with cymene, α-pinene, β-pinene, terpineol, pinocarveol, ledol, aromadendrene and others. The leaf also contains the flavonoids rutin, hyperoside and quercitrin, with tannins and other polyphenolics including tellimagrandin, catechins, and a series of euglobals, macracarpals and cypellogins (Boulekbache-Makhlouf et al. 2013; EMA 2012a; Williamson 2003).

Few clinical studies on eucalyptus oil and preparations have been carried out for the treatment of upper respiratory tract infections such as cold and cough, although there is a very long history of use for these purposes (Sadlon and Lamson 2010). Several clinical studies have been published on its major constituent (1,8-cineole) (EMA 2012b; ESCOP 2003). Cineole showed some beneficial effects in rhinosinusitis (Kehrl et al. 2004) and obstructive pulmonary diseases (Worth et al. 2009) and has anti-inflammatory activity (Juergens et al. 2003). The oil has been shown to have insect-repellent as well as insecticidal and larvicidal properties (Williamson 2003).