Hypotensive and vasorelaxant effects of (E) - methyl isoeugenol: a naturally occurring food flavour.

Application of naturally occurring (E) - methyl isoeugenol (MIE) as food flavour has been widely accepted despite the growing concerns over cardiovascular issue. Hence, we sought to investigate hypotensive property of MIE and the involvement of central and/or peripheral mechanism (s). Variation in mean arterial pressure (MAP), heart rate (HR), systolic blood pressure (SBP), baroreflex sensitivity of normotensive rats and vascular reactivity were recorded. MIE (1.11, 2.25 or 4.50mg/kg, iv) elicited dose-related decrease in MAP (-16.9±1.13; -19.0±4.18 or -27.2±3.65mmHg, respectively) and an increase in HR (17.4±1.79; 24.4±5.11 or 29.9±6.62 bmp, respectively). MIE 25 or 50mg/kg (p.o) reduced the SBP (-13.6±4.18 or -16.6±5.60mmHg, respectively) without altering baroreflex sensitivity. The hypotensive effect of MIE remained unaltered by WAY100635 (antagonist of 5-HT1A) and L-NAME (NO synthase inhibitor). Intracerebroventricular injection of MIE did not change MAP. MIE elicited endothelium independent vasorelaxation (endothelium-intact vessels, Emax 92.5±1.75%; Endothelium-denuded vessels, Emax 91.4±2.79%). MIE blocked CaCl2 or BAY K8644 (L-type voltage gated calcium channel activator)-induced vascular contractions. Our findings showed evidence of hypotensive and vasorelaxation effects of MIE with involvement of calcium channel.