EFFECTS OF OLEA-EUROPAEA L EXTRACT ON THE RAT ISOLATED ILEUM AND TRACHEA

The effects of an Olea europaea L. dried leaf extract containing 3.2% of oleuropein were investigated on the rat isolated ileum and trachea. On basal tone rat isolated ileum, Olea europaea L. extract was shown to produce a dual effect characterized by a contraction at low doses ( 10(-7)-10(-4)g/mL) and a relaxation at high doses (3.10(-4)-10(-3)g/mL ). The extract induced contractile effect was found to involve at leas t histamine, 5-hydroxytryptamine and thromboxane A(2). On precontracte d rat isolated ileum, the extract only induced a relaxation that was n ot modified by nifedipine, diltiazem, dipyridamone, verapamil or papav erine (10(-6) M). The effects of the extract were also studied on the rat isolated trachea. On basal tone organs, Olea europaea L. extract d id not produce any effect, whereas, when basal tone was raised by acet ylcholine (ACh 10(-3) M), the drug caused a relaxation (maximal effect 39.01% +/- 5.40% of the response to theophylline; (3.10 x 10(-3)M n = 15). It is suggested that the induced relaxation is consecutive to an increase of intracellular 3'5' cAMP.