Antispasmodic Activity of Origanum compactum

Abstract

Origanum compactum has been studied for antispasmodic activity, using different smooth muscle preparations of the alimentary canal in vitro: the guinea-pig ileum and duodenum, the rat fundus strip and duodenum. Aqueous extract of Origanum powder inhibits responses to acetylcholine, histamine, Serotonine, BaCl₂, 1,1-dimethyl-4-phenylpiperazinium iodide and nicotine in the guinea-pig ileum. The extract also blocks contractions elicited by electrical coaxial stimulation. Responses to cumulative increased Ca²⁺ concentrations in depolarizing bathing medium were also blocked. Thymol and carvacrol were found to be the active components. The results indicate that antispasmodic activity is caused by a direct and indirect action on the smooth muscle. It is suggested that muscle relaxant effect results from a decrease of the Ca²⁺ availability for muscle contraction by I) blocking the release of intracellular bound Ca²⁺ and 2) prevention of the extracellular Ca²⁺ influx in the smooth muscle cell. Inhibition of the nerve action potential in the postganglionic nerve fibre is proposed to be the indirect action of spasmolytic activity.

Key Word Index

Origanum compactum - Labiatae - Thymol - Carvacrol - Essential Oil - Antispasmodic Activity.