Studies on the chemical composition and possible mechanisms underlying the antispasmodic and bronchodilatory activities of the essential oil of Artemisia maritima L.

Abstract

This study describes the chemical composition of the essential oil of Artemisia maritima (Am.Oil) and the pharmacological basis for its medicinal use in gut and airways disorders. Twenty five compounds, composing 93.7% of the oil, were identified; among these, chrysanthenyl propionate and elixene were identified for the first time from any Artemisia species. The Am.Oil (0.3-1.0 mg/mL) suppressed spontaneous and high K(+) (80 mM)-induced contractions in isolated rabbit jejunum, suggestive of an antispasmodic effect mediated possibly through calcium channel blockade. The calcium channel blockade activity was confirmed when pre-treatment of the tissue with Am.Oil (0.01-0.03 mg/mL) shifted the Ca(++) concentration-response curves to the right, similar to verapamil and papaverine. In isolated tracheal strips, Am.Oil inhibited carbachol (CCh; 1 μM)-induced contractions more than that induced by K(+) and shifted the isoprenaline-induced inhibitory CRCs to the left, similar to papaverine, suggestive of potentiation, while, verapamil was more potent against K(+) than CCh-induced contractions and had no potentiating effect on isoprenaline-induced inhibitory CRCs. These data indicate that the Am.Oil exhibited spasmolytic and bronchodilator activities mediated possibly through dual blockade of calcium channels and phosphodiesterase, which provides the pharmacological basis to the medicinal use of Artemisia maritima in colic, diarrhea and possibly asthma.