Antispasmodic effects of essential oil of Pterodon polygalaeflorus and its main constituent β-caryophyllene on rat isolated ileum

• Published in: Fundamental & clinical pharmacology 2010-12, Vol.24 (6), p.749-758
• Main Authors: Leonhardt, Valeria, Leal-Cardoso, José H., Lahlou, Saad, Albuquerque, Aline A.C., Porto, Romulo S., Celedônio, Natalia R., Oliveira, Ariclecio C., Pereira, Renalison F., Silva, Leidiane P., Garcia-Teófilo, Taylena M.N., Silva, Anna P.F.S., Magalhães, Pedro J.C., Duarte, Gloria P., Coelho-de-Souza, Andrelina N.
• Format: Article
• Language: English
• Subjects: Acetylcholine - pharmacology; Animals; antispasmodic effect; Biological and medical sciences; Calcium - physiology; Dose-Response Relationship, Drug; essential oil; Fabaceae - chemistry; ileal smooth muscle; Ileum - drug effects; Ileum - physiology; In Vitro Techniques; Medical sciences; Muscle Contraction - drug effects; Muscle, Smooth - drug effects; Muscle, Smooth - physiology; Oils, Volatile - pharmacology; Parasympatholytics - pharmacology; Pharmacology. Drug treatments; Plant Oils - pharmacology; Potassium Chloride - pharmacology; Pterodon polygalaeflorus; Rats; Sesquiterpenes - pharmacology; Verapamil - pharmacology; β-caryophyllene
• ISSN: 0767-3981; 1472-8206
• DOI: 10.1111/j.1472-8206.2009.00800.x

This study investigates the effects of essential oil of Pterodon polygalaeflorus (EOPP) and β‐caryophyllene (β‐CAR). EOPP and β‐CAR relaxed the basal tone of ileum smooth muscle in a concentration‐dependent manner (IC50s = 394.35 ± 62.12 and 68.65 ± 9.51 μg/mL respectively), an effect that was unaltered by hexamethonium, L‐nitroarginine methyl ester or indomethacin. Both EOPP and β‐CAR evoked a concentration‐dependent relaxation of ileum pre‐contracted with KCl with an IC50 value of 107.78 ± 10.47 and 17.35 ± 0.75 μg/mL, respectively. EOPP and β‐CAR inhibited the contractions induced by acetylcholine (ACh) and by KCl. In ileal preparations, the CaCl2‐induced contractions were reduced by EOPP (300 μg/mL) and β‐CAR (100 μg/mL). Furthermore, CaCl2‐induced contractions were also reduced by EOPP (300 μg/mL) and β‐CAR (100 μg/mL) in ileal preparations pretreated with ACh under Ca2+‐free condition and in the presence of verapamil. EOPP (100 and 300 μg/mL) and β‐CAR (30 and 100 μg/mL) reduced the ACh‐induced contractions of isolated rat ileum under Ca2+‐free conditions. In the presence of high KCl and Ca2+‐free conditions, EOPP (300 μg/mL) and β‐CAR (100 μg/mL) reduced the contractions induced by barium. A similar effect was also observed with verapamil. It is concluded that (i) β‐CAR is an important constituent involved in the myorelaxant and antispasmodic effects induced by EOPP; (ii) the inhibitory effect on intestinal contractility is myogenic and seems mainly mediated through an intracellular mechanism. However, the ability of EOPP and β‐CAR to decrease Ca2+ influx through cytoplasmic membrane could not be discounted.