Eucalyptus is a tree originating from Australia. There are several hundred species of Eucalyptus. Many eucalyptus trees are known as gum trees; other names for various species include mallee, box, stringybark, and ash. Cineole is a chief constituent of eucalyptus oil and constitutes almost 80% of this essential oil.

Eucalyptus Research
Antibacterial effects of Eucalyptus globulus leaf extract on pathogenic bacteria isolated from specimens of patients with respiratory tract disorders.
Clin Microbiol Infect. 2006 Feb;12(2):194-6.
Department of Pathobiology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran.
The antibacterial activity of Eucalyptus globulus leaf extract was determined for 56 isolates of Staphylococcus aureus, 25 isolates of Streptococcus pyogenes, 12 isolates of Streptococcus pneumoniae and seven isolates of Haemophilus influenzae obtained from 200 clinical specimens of patients with respiratory tract disorders. MIC(50)s for these species were 64, 32, 16 and 16 mg/L, respectively; MIC(90)s were 128, 64, 32 and 32 mg/L, respectively; and MBCs were 512, 128, 64 and 64 mg/L, respectively. These results suggest that further studies to clarify the possible therapeutic role of Eucalyptus globulus leaf extract in the treatment of respiratory tract infection are warranted.

[Local tolerability of two preparations with eucalyptus oil and pine-needle oil]
MMW Fortschr Med. 2005 Oct 6;147 Suppl 3:109-12.
The objective of this open-label, single-centre study was to assess the tolerability of two locally applicable eucalyptus oil and pine-needle oil preparations using patch testing as an accepted and standardised method. METHOD: Two eucalyptus oil and pine-needle oil preparations were applied to the forearm of 46 subjects with healthy skin using standardised patches. The patches were removed after 48 hours and skin reactions were assessed immediately and after 24 and 48 hours. The major objective was the reaction of the patch test. RESULT: Neither preparation caused any positive skin reaction in any of the subjects. CONCLUSION: Skin tolerability to the two eucalyptus oil and pine-needle oil preparations is very good with regard to their active ingredients and other excipients.

Eucalyptus globulus (camphor oil) against the zoonotic scabies, Sarcoptes scabiei.
J Egypt Soc Parasitol. 2003 Apr;33(1):47-53.
Department of Parasitology, Faculty of Medicine, Ain Shams University, Cairo 11566, Egypt.
In Egypt, Scarcoptes scabiei is the most prevalence mites of medical importance infesting man. This is true in overcrowded and poorly hygienic areas. Many effective acaridical regimens are available, but being compounds used as insecticides. With the success of camphor oil in treated human demodicidosis, it was applied for treating human scabies. Camphor oil with or without glycerol dilutions gave complete cure, with concentrations (100%, 75% and 50%) within five to ten days.

Anti-inflammatory activity of 1.8-cineol (eucalyptol) in bronchial asthma: a double-blind placebo-controlled trial.
Respir Med. 2003 Mar;97(3):250-6.
Department of Pneumology, Medical Outpatient Clinic, Bonn University Hospital, Germany.
Airway hypersecretion is mediated by increased release of inflammatory mediators and can be improved by inhibition of mediator production. We have recently reported that 1.8-cineol (eucalyptol) which is known as the major monoterpene of eucalyptus oil suppressed arachidonic acid metabolism and cytokine production in human monocytes. Therefore, the aim of this study was to evaluate the anti-inflammatory efficacy of 1.8-cineol by determining its prednisolone equivalent potency in patients with severe asthma. Thirty-two patients with steroid-dependent bronchial asthma were enrolled in a double-blind, placebo-controlled trial. After determining the effective oral steroid dosage during a 2 month run-in phase, subjects were randomly allocated to receive either 200 mg 1.8-cineol t. i.d. or placebo in small gut soluble capsules for 12 weeks. Oral glucocorticosteroids were reduced by 2.5 mg increments every 3 weeks. The primary end point of this investigation was to establish the oral glucocorticosteroid-sparing capacity of 1.8-cineol in severe asthma. Reductions in daily prednisolone dosage of 36% with active treatment vs. a decrease of only 7% in the placebo group were tolerated. Twelve of 16 cineol vs. four out of 16 placebo patients achieved a reduction of oral steroids (P = 0.012). Long-term systemic therapy with 1.8-cineol has asignificant steroid-saving effect in steroid-depending asthma. This is the first evidence suggesting an anti-inflammatory activity of the monoterpene 1.8-cineol in asthma and a new rational for its use as mucolytic agent in upper and lower airway diseases.

Eucalyptus leaf email
Q. Is it possible to smoke the eucalyptus leaf? A friend of mine says in India they smoke the eucalyptus leaf.
     A. When I was in Greece I met a Swiss woman who was married to a man from India and she had cigarettes with her that were crushed eucalyptus leaves. I took a couple of puffs and noticed a slight buzz for about 10 minutes.