Natural Products Useful in Respiratory Disorders: Focus on Side-Effect Neutralizing Combinations : Medicinal Plants Application in Asthma and Cough

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.

An extensive ethnopharmacological survey was conducted among the most well known Arabic indigenous herbal practitioners in Israel, the Golan Heights and the West Bank in order to evaluate the potential of local plants used in treating different diseases and illnesses. Thirty-one indigenous practitioners' of Arabic traditional medicine ranging in age from 40 to 116 years, were interviewed using a previously prepared questionnaire. The current survey revealed that 129 plant species are still in use in Arabic traditional medicine for the treatments of various diseases. Among these plants, there are 40 species used for treating skin diseases, 27 species for treating kidney and urinary system, 26 species for treating diabetes, 23 species for treating digestive system including stomach and intestinal pain and inflammation, 22 species for treating liver diseases, 16 species for treating respiratory system and coughing, 13 species for treating forms of cancer and nine species for treating weight loss and cholesterol reduction. Additional findings and implications of this current survey including preparation methods and route of use are discussed in this report.