Relaxant effect ofThymus vulgaris on guinea-pig tracheal chains and its possible mechanism(s)

Abstract

Thymus vulgaris for the treatment of respiratory diseases is indicated widely, and relaxant effects on smooth muscle have been shown previously. In the present study, the relaxant effects of macerated and aqueous extracts of Thymus vulgaris on tracheal chains of guinea-pigs were examined using cumulative concentrations of macerated and aqueous extracts in comparison with saline (as the negative control) and theophylline (as the positive control). The relaxant effects of four cumulative concentrations of macerated and aqueous extracts (0.25, 0.5, 0.75 and 1.0 g %) in comparison with saline (as the negative control) and four cumulative concentrations of theophylline (0.25, 0.5, 0.75 and 1.0 mm; as the positive control) were examined for their relaxant effects on precontracted tracheal chains of guinea-pig by 60 mm KCl and 10 microm methacholine in two different conditions: non-incubated tissues and incubated tissues with 1 microm propranolol and 1 microm chlorphenamine. There were significant correlations between the relaxant effects and the concentrations for both extracts and theophylline in all experimental groups (p < 0.01 to p < 0.001). These results demonstrated a potent relaxant effect of Thymus vulgaris on guinea-pig tracheal chains that was comparable to theophylline at the concentrations used.

A review of the relaxant effect of various medicinal plants on tracheal smooth muscle, their possible mechanism(s) and potency

“…basilicum) and Cuminum cyminum L. (C. cyminum) exert a more potent relaxant effect on tracheal smooth muscles contracted by methacholine than by KCl, which suggests their calcium channel-blocking effect (Boskabady et al, 2005a;Boskabady et al, 2005b).…”

The effect of carvacrol on muscarinic receptors of guinea‐pig tracheal chains

“…In addition, all plants containing carvacrol showed a relaxant effect on different smooth muscles including trachea (Gharib Naseri, 2003;Reiter and Brandt, 1985;Boskabady et al, 2006;Boskabady et al, 2007;Boskabady et al, 1998;Hajhashemi et al, 2000;Boskabady et al, 2007).…”

Traditional Use of Herbal Remedies in Livestock by Farmers in 3 Swiss Cantons (Aargau, Zurich, Schaffhausen)

“…In veterinary medicine, thyme preparations are recommended for gastrointestinal diseases, metabolic dysfunctions, and respiratory tract disorders [27]. Thymol and carvacrol are the major constituents of the essential oil [28,29]; the bronchodilating properties have been demonstrated with isolated tracheas of guinea pigs [31]. 2 of the 3 daily oral doses recorded in our survey were in the recommended range for oral administrations for humans and animals (table 3) [27,28], 1 dosage was 20 times higher.…”