Antispasmodic effects of the essential oil of Croton zehnteneri, anethole, and estragole, on tracheal smooth muscle

Crystianne Calado Lima; Camille Maria de Holanda-Angelin-Alves; Átila Pereira-Gonçalves; Emanuel Kennedy-Feitosa; Eder Evangelista-Costa; Maria Amelia Carneiro Bezerra; Andrelina Noronha Coelho-de-Souza; José Henrique Leal-Cardoso

doi:10.1016/j.heliyon.2020.e05445

Antispasmodic effects of the essential oil of Croton zehnteneri, anethole, and estragole, on tracheal smooth muscle

Heliyon. 2020 Nov 16;6(11):e05445. doi: 10.1016/j.heliyon.2020.e05445. eCollection 2020 Nov.

Authors

Crystianne Calado Lima¹, Camille Maria de Holanda-Angelin-Alves², Átila Pereira-Gonçalves², Emanuel Kennedy-Feitosa³, Eder Evangelista-Costa², Maria Amelia Carneiro Bezerra⁴, Andrelina Noronha Coelho-de-Souza², José Henrique Leal-Cardoso²

Affiliations

¹ Laboratory of Pulmonary Physiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil.
² Laboratory of Electrophysiology, Superior Institute of Biomedical Sciences, State University of Ceará, Fortaleza, Ceará, Brazil.
³ Department of Health Sciences, Federal Rural University of Semi-Arid, Mossorró, Rio Grande do Norte, Brazil.
⁴ Centre of Health Sciences, State University Vale do Acaraú, Sobral, Ceará, Brazil.

Abstract

Croton zehntneri is a plant well adapted to the semi-arid climate of northeastern region of Brazil. The essential oil of C. zehntneri (EOCz) has been described to have several pharmacologic properties, including effect on airflow resistance of in vivo respiratory system. For this reason, we investigated the hypothesis that EOCz and its major constituents, anethole and estragole, have antispasmodic activity on tracheal muscle. In tracheal rings of Wistar rats, maintained in Krebs-Henseleit's solution, EOCz, anethole and estragole inhibited contractions induced by 60mM [K⁺], ACh (10μM), Ba²⁺ and Phorbol dibutirate (1 μM). For EOCz, anethole and estragole, the IC₅₀ for inhibition of KCl-induced contractions were 145.8 ± 14.8, 89.9 ± 7.4 and 181.0 ± 23.3 μg/mL, respectively, and for ACh-induced contraction, they were 606.1 ± 122.0, 160.5 ± 33.0 and 358.6 ± 49.2 μg/mL. Pharmacodynamic efficacy was maximal in all cases. These data in Ba²⁺-induced contraction and the differential IC₅₀ suggested that blockade of Voltage Dependent Calcium Channels (VDCC) is a component of the mechanism of action of the three agents. Evaluation of the direct effect of anethole, on VDCC, showed inhibition of the Ca²⁺ current through this type of channel. These results show that EOCz and the constituents have antispasmodic activity and the mechanism includes blockade of VDCC channels.

Keywords: Anethole; Antispasmodic effect; Croton zehntneri; Dose-response relationship; Essential oil; Estragole; Natural product; Organ system; Pharmaceutical science; Respiratory system; Trachealis smooth muscle.