Vasorelaxant Effect Induced by the Essential Oil of Ocotea duckei Vattimo Leaves and Its Main Constituent, Trans-caryophyllene, in Rat Mesenteric Artery
Renildo Moura da Cunha
Center of Biological Sciences and Nature, Federal University of Acre, Rio Branco, Acre, Brazil
Tays Amanda Felisberto Gonçalves
Department of Pharmaceutical Sciences, Health Sciences Center, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil
Anselmo Fortunato Ruiz Rodriguez
Department of Pharmaceutical Sciences, Health Sciences Center, Universidade Federal da Paraíba (UFPB), João Pessoa, Paraíba, Brazil.
Dionatas Ulises de Oliveira Meneguetti
Application School, Federal University of Acre, Rio Branco, Acre, Brazil.
Marcio Roberto Viana Santos
Department of Physiology, Federal University of Sergipe (UFS), São Cristóvão, Sergipe, Brazil.
José Maria Barbosa- Filho
Department of Pharmaceutical Sciences, Health Sciences Center, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil
Êurica Adélia Nogueira Ribeiro
School of Nursing and Pharmacy, Federal University of Alagoas (UFAL), Maceió, Alagoas, Brazil.
Eryvaldo Sócrates Tabosa do Egito
Department of Pharmacy, Health Sciences Centre, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande no Norte, Brazil.
Isac Almeida de Medeiros *
Department of Pharmaceutical Sciences, Health Sciences Center, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil
*Author to whom correspondence should be addressed.
Abstract
Aims: To evaluate the vasorelaxant effect induced by the essential oil of the leaves of O. duckei Vattimo (ODEO) and its main constituent, trans-caryophyllene, in rat superior mesenteric arteries.
Methodology: Isolated rat superior mesenteric rings were suspended by cotton threads for isometric tension recordings in Tyrode’s solution at 37ºC, gassed with 95% O2 and 5% CO2 and different ODEO concentrations (0.1-300 μg/mL) or trans-caryophyllene (1-1000 μg/mL) were added cumulatively to the organ baths.
Results: Vasorelaxant effect induced by the essential oil of Ocotea duckei leaves (ODEO) and its main constituent, trans-caryophyllene (60.54 %), was evaluated in this work. In intact isolated rat superior mesenteric rings ODEO (0.1-300 μg/mL, n=6) induced concentration-dependent relaxation of tonus induced by phenylephrine (10 µM) or K+-depolarizing solution (KCl 80 mM) (IC50=31±5, 5±0.4 µg/mL, respectively, n=6). The relaxations of phenylephrine-induced contractions were not significantly attenuated after removal of the vascular endothelium (IC50=25±5 µg/mL). ODEO antagonized the concentration-response curves to CaCl2 (10-6-3x10-2 M) and Bay K 8644 (10-10-3x10-6 M). Furthermore, in nominally without calcium solution, ODEO significantly inhibited, in a concentration-dependent manner, transient contractions induced by 10 µM phenylephrine or 20 µM caffeine. Trans-caryophyllene induced vasorelaxations, however, this effect was 18.6 times less potent when compared to ODEO-induced vasorelaxations.
Conclusion: The relaxant effect induced by ODEO in rat superior mesenteric artery rings is endothelium-independent and seems to be related to both, inhibition of Ca2+ influx through L-type voltage-gated Ca2+-channels sensitive to dihydropyridines and inhibition of the calcium release from intracellular IP3-and caffeine-sensitive stores.
Keywords: Ocotea duckei, essential oil, vasorelaxant effect, rat superior mesenteric artery, calcium channels.