Abstract
The effects of the essential oil of Eucalyptus tereticornis Sm. (EOET) on guinea-pig tracheal smooth muscle were investigated. EOET (10 - 1000 μg/mL) relaxed the tracheal basal tonus with an EC50 value of 125.3 [52.2 - 300.9] μg/mL. Its maximal relaxation (40 ± 6 %) was significantly lower than that evoked by aminophylline (209 ± 34 %). The K+-(60 mM)-induced contractions were significantly reduced by both EOET (200 - 1000 μg/mL) and its main constituent 1,8-cineole (600 - 1000 μg/mL). Acetylcholine (1 μM)-induced contractions were significantly enhanced by 1,8-cineole (10 - 1000 μg/mL). However, they were significantly enhanced and reduced by lower (200 - 400 μg/mL) and higher (800 - 1000 μg/mL) concentrations of EOET, respectively. Electrical field stimulation-induced contractions were significantly increased by EOET (100 - 600 μg/mL). In conclusion, EOET produces myorelaxant effects on guinea-pig isolated trachea, an effect that seems to result from a complex interaction between its monoterpenoid constituents.
References
-
1
Dagne E, Bisrat D, Alemayehu M, Worku T.
Essential oils of twelve Eucalyptus species from Ethiopia.
J Essent Oil Res.
2000;
12
467-70
-
2 Matos F JA. Farmácias vivas. Fortaleza. Brazil; Edicões UFC 2001
-
3
Silva J, Abebe W, Sousa S M, Duarte V G, Machado M I, Matos F J.
Analgesic and anti-inflammatory effects of essential oils of Eucalyptus
.
J Ethnopharmacol.
2003;
89
277-83
-
4
Juergens U R, Dethlefsen U, Steinkamp G, Gillissen A, Repges R, Vetter H.
Anti-inflammatory activity of 1,8-cineole (eucalyptol) in bronchial asthma: a double-blind placebo-controlled trial.
Respir Med.
2003;
97
250-6
-
5
Juergens U R, Stober M, Vetter H.
Inhibition of cytokine production and arachidonic acid metabolism by eucalyptol (1,8-cineole) in human blood monocytes in vitro
.
Eur J Med Res.
1998;
3
508-10
-
6
Matsuda F, Sugahara K, Sugita M, Sadohara T, Kiyota T, Terasaki H.
Comparative effect of amrinone, aminophylline and diltiazem on rat airway smooth muscle.
Acta Anaesthesiol Scand.
2000;
44
763-6
-
7
Cohen B M, Dressler W E.
Acute aromatics inhalation modifies the airways. Effects of the common cold.
Respiration.
1982;
43
285-93
-
8
Perry N S, Houghton P J, Theobald A, Jenner P, Perry E K.
In vitro inhibition of human erythrocyte acetylcholinesterase by Salvia lavandulaefolia essential oil and constituent terpenes.
J Pharm Pharmacol.
2000;
52
895-902
-
9
Mills C, Cleary B J, Gilmer J F, Walsh J J.
Inhibition of acetylcholinesterase by Tea Tree oil.
J Pharm Pharmacol.
2004;
56
375-9
-
10
Sadraei H, Asghari G R, Hajhashemi V, Kolagar A, Ebrahimi M.
Spasmolytic activity of essential oil and various extracts of Ferula gummosa Boiss. on ileum contractions.
Phytomedicine.
2001;
8
370-6
-
11
Câmara C C, Nascimento N R, Macedo-Filho C L, Almeida F B, Fonteles M C.
Antispasmodic effect of the essential oil of Plectranthus barbatus and some major constituents on the guinea-pig ileum.
Planta Med.
2003;
69
1080-5
-
12
Magalhães P JC, Criddle D N, Tavares R A, Melo E M, Mota T L, Leal-Cardoso J H.
Intestinal myorelaxant and antispasmodic effects of the essential oil of Croton nepetaefolius and its constituents cineole, methyl-eugenol and terpineol.
Phytother Res.
1998;
12
172-7
-
13
Magalhães P J, Lahlou S, Vasconcelos dos Santos M A, Pradines T L, Leal-Cardoso J H.
Myorelaxant effects of the essential oil of Croton nepetaefolius on the contractile activity of the guinea-pig tracheal smooth muscle.
Planta Med.
2003;
69
74-7
-
14
Magalhães P J, Lahlou S, Leal-Cardoso J H.
Antispasmodic effects of the essential oil of Croton nepetaefolius on guinea-pig ileum: a myogenic activity.
Fundam Clin Pharmacol.
2004;
18
539-46
-
15 Craveiro A A, Fernandes A G, Andrade C HS, Matos F JA, Alencar J W, Machado M IL. Óleos essenciais de plantas do Nordeste. Fortaleza, Brasil; Edições UFC 1981
-
16
Alencar J W, Craveiro A A, Matos F JA.
Kovat indices as a preselection routine in mass spectra library search of volatiles.
J Nat Prod.
1984;
47
890-2
Prof. Pedro J. C. Magalhães
Departamento de Fisiologia e Farmacologia
Universidade Federal do Ceará
Rua Cel. Nunes de Melo 1127
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Brazil
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Email: pjcmagal@ufc.br