The Antispasmodic Effect of Warionia saharae Essential Oil in Experimental Models and its Mechanism of Action

Abstract

With several medicinal and aromatic species, the Asteraceae family is one of the largest angiosperm families. The genus Warionia is represented in this family by only one species, Warionia saharae. In Moroccan traditional medicine, this species is widely used to treat gastrointestinal problems. Essential oil of this plant (EoWs) was studied for possible myorelaxant and antispasmodic activities to rationalize some of the traditional uses. In this investigation, hydrodistillation was used to obtain the essential oil from the aerial part of the dry plant extract (EoWs), which was then analyzed using gas chromatography coupled to mass spectrometry (GC/MS). The major compounds identified in the EoWs are nerolidyl acetate (21.44%), β-Eudesmol (19.47%), linalool (16.48%), 1-terpinene-4-ol (10.93%), and cineole (5.34%). EoWs is relatively safe in the case of acute intake up to 2 g/kg body weight of albino mice. The effect of EoWs on intestinal relaxation was investigated using rabbit and rat jejunal smooth muscle. We have noticed that EoWs produce a myorelaxation on basal rabbit jejunum's contractions in a concentration-dependent manner with a maximal effect at 30 µg/mL. This myorelaxation was not dependent on adrenergic receptors. When the rat jejunums were pre-contracted with 25 mM KCl or 10 µM Carbachol (CCh), EoWs had an antispasmodic action with an IC50 values of 15.76 ± 0.37 and 12.04 ± 0.30 µg/mL, respectively. Preliminary results showed that it is probable that our plant might act directly through the NO and guanylate cyclase signaling pathway and on muscarinic but not nicotinic receptors. The results reveal that the Essential oil of W. saharae appears to have an impact on intestinal relaxation in vitro conditions. This finding lends credence to the traditional usage of this plant to treat intestinal disorders.