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Planta Med 2002; 68(12): 1097-1102
DOI: 10.1055/s-2002-36336
Original Paper
© Georg Thieme Verlag Stuttgart · New York

Cardiovascular Effects of the Essential Oil of Alpinia zerumbet Leaves and its Main Constituent, Terpinen-4-ol, in Rats: Role of the Autonomic Nervous System

Saad Lahlou1 , Charles Antonio Barros Galindo1 , José Henrique Leal-Cardoso2 , Manassés Claudino Fonteles3 , Gloria Pinto Duarte1
  • 1Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife-PE, Brasil
  • 2Departamento de Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza-CE, Brasil
  • 3Faculdade de Veterinária, Universidade Estadual do Ceará, Fortaleza-CE, Brasil
Further Information

Publication History

Received: April 16, 2002

Accepted: June 29, 2002

Publication Date:
20 December 2002 (online)

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Abstract

Cardiovascular effects of intravenous (i. v.) treatment with the essential oil of Alpinia zerumbet (EOAZ) were investigated in rats. Additionally this study examined (I) whether the autonomic nervous system is involved in the mediation of EOAZ-induced changes in mean aortic pressure (MAP) and heart rate (HR), and (II) whether these changes could be, at least in part, attributed to the actions of terpinen-4-ol (Trp-4-ol), the major constituent of EOAZ. In both pentobarbitone-anaesthetised and conscious rats, i. v. bolus injections of EOAZ (1 to 20 mg/kg) elicited immediate and dose-dependent decreases in MAP. In anaesthetised rats, EOAZ decreased HR only at higher doses (10 and 20 mg/kg), while changes of this parameter were not uniform in conscious rats. Hypotensive responses to EOAZ were of the same order of magnitude or duration, irrespective of whether the animal was under general anaesthesia. Pretreatment of anaesthetised rats with bilateral vagotomy did not modify significantly the hypotensive and bradycardic responses to EOAZ. In conscious rats, i. v. injections of bolus doses (1 to 10 mg/kg) of Trp-4-ol also elicited immediate and dose-dependent decreases in MAP. However, these hypotensive effects were significantly greater than those evoked by the same doses of EOAZ (1 to 10 mg/kg). Intravenous pretreatment of conscious rats with either methylatropine (1 mg/kg) or hexamethonium (30 mg/kg) had no significant effects on the EOAZ-induced hypotension. These data show that i. v. treatment with the EOAZ in either anaesthetised or conscious rats induced an immediate and significant hypotension, an effect that could be partially attributed to the actions of Trp-4-ol. The hypotension appears independent of the presence of an operational sympathetic nervous system, suggesting that the EOAZ may be a direct vasorelaxant agent.

Key words

Alpinia zerumbet - Zingiberaceae - essential oil - terpinen-4-ol - cardiovascular effects - autonomic nervous system - rat