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

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.

Hypotensive effect and endothelium-dependent vascular action of leaves of Alpinia purpurata (Vieill) K. Schum

“…Additionally, blood pressure reduction was higher in magnitude in SHR than in normotensive animals (p < .01) at all doses of EEAP, and in all but the two weakest doses of the IAP. Several studies have shown a blood pressure-lowering effect of AZ, a species very similar to AP (Mendonça et al, 1991;Mpalatinos et al, 1998;Lahlou et al, 2002Lahlou et al, , 2003De Moura et al, 2005;Barcelos et al, 2010). The study by Mendonça et al (1991) demonstrated an important blood pressure-lowering effect of the alcoholic extract of AZ in rats.…”

“…The study by Mendonça et al (1991) demonstrated an important blood pressure-lowering effect of the alcoholic extract of AZ in rats. Lahlou et al (2002) observed that i.v. treatment with the essential oil of AZ induces immediate and significant hypotension in rats.…”

Hypotensive activity, toxicology and histopathology of different extracts of Berberis vulgaris

“…The acute intravenous administration of different extract of B. vulgaris (BRE, BRD) as well as Ach used as positive reference drug (Lahlou et al, 2002) in this study, all exerted immediate and significant fall in systolic, diastolic and mean arterial blood pressure (MABP) in normotensive anaesthetized rats.…”

Teor e composição química do óleo essencial de alpínia em razão da adubação e da disponibilidade de água no solo

“…É indicada principalmente no tratamento da hipertensão e da ansiedade (Matos, 2002); porém, outras propriedades lhe são mencionadas: diurética, estimulante do peristaltismo intestinal, emenagoga, antiulcerogênica, ação expectorante, usada em afecções respiratórias, intestinais e renais, amigdalite, faringite, rouquidão, reumatismo, nevralgia e dores lombares e musculares (Côrrea, 1974;Alice et al, 1995;Panizza, 1997). Em virtude disso, a espécie tornou-se referência de várias pesquisas (Bezerra et al, 2000;Chaves, 2001;Lahlou et al, 2002).…”

“…O terpinen-4-ol é considerado o principal constituinte químico do óleo essencial de A. zerumbet (Lahlou et al, 2002). Usando a ressonância magnética nuclear ( 13 C-NMR) como técnica de identificação complementar na análise de óleo essencial de A. zerumbet, Alencar et al (1997) identificaram ρ-cimeno (33,1%), 1,8-cineol (18,9%), (Ε)-terpinen-4-ol (18,8%) e sabineno (8,2%) como os constituintes em maior proporção.…”