Background:

accumulating evidence suggests that natural compounds and specifically monoterpenes exert a vasodilator action.

Objective:

to investigate the vascular effects of isoespintanol (2-isopropil-3,6- dimetoxi-5-metilfenol, ISO) monoterpene isolated from the leaves of Oxandra cf xylopioides.

Methods:

thoracic aortic rings isolated from Wistar rats were contracted with KCl 80 mM and then relaxed by exposure to Ca2+-free solution in absence and in presence of ISO 0.6 μg/mL. The force/tissue ratio (F/W) and the time to obtain 50% of relaxation (T-50) were used to assess the maximal contractile response and the relaxation, respectively. To examine the participation of NO additional experiments were performed under inhibition of nitric oxide synthase with L-NAME (L-NG-Nitroarginine methyl ester).

Results:

ISO significantly decreased the F/W ratio (257 ± 19 vs. 360 ± 18) and did not change T-50. In presence of L-NAME the effects of ISO on contractile response was abolished.

Conclusions:

these results demonstrate that ISO exerts a vasodilator effect through NO-dependent pathways and suggest that an inhibition of calcium influx could be the involved mechanism.

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