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 (range 2.5-10 mg, mean: 3.75 mg) vs. a decrease of only 7% (2.5-5 mg, mean: 0.91 mg) in the placebo group (P = 0.006) 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.

ISRCTN07600011.

In patients with acute nonpurulent rhinosinusitis, timely treatment with cineole is effective and safe before antibiotics are indicated.

ObjectiveCineole has mucolytic, bronchodilating and anti-inflammatory properties and reduces the exacerbation rate in patients suffering from COPD, as well as ameliorates symptoms in patients suffering from asthma and rhinosinusitis. Based on these effects, we therefore postulated the hypothesis that patients with acute bronchitis would also benefit from therapy with Cineole.MethodsAs part of a double-blind, placebo-controlled, multi-center-study, a total of 242 patients with confirmed acute bronchitis was randomly selected to participate. Over a period of 10 days, all patients were administered 3 x 200 mg of Cineole, or a respective placebo, per day. The primary outcome measure was a Bronchitis Sum Score, which summarises the relevant symptoms of acute bronchitis.ResultsAfter 4 days of treatment it was notable, that the patient group treated with Cineole, showed significantly more improvements of the bronchitis-sum-score than those of the placebo group (p = 0.0383). The statistical significant difference of the individual outcome measures was especially underlined by the frequency of cough fits by p = 0.0001 after 4 days.ConclusionsThe effects of Cineole in the treatment of acute bronchitis were clearly measurable and could be proven after a treatment period of merely 4 days. This study corroborates the fact that Cineole actively and significantly reduces cough frequency after four days. Therefore it has been shown to have a great socioeconomic impact.Trial registrationISRCTN: ISRCTN37784439

Concomitant therapy using cineole can lead to notable improvement in lung function and health condition as well as to reduce dyspnea in asthma patients.