Ca2+ antagonist and cholinergic activities explain the medicinal use of olive in gut disorders

The crude extract of olive or Olea europea fruit (OeF.Cr) and its fractions were studied in vitro for the possible spasmolytic and spasmogenic activities to rationalize some of its medicinal uses. In isolated rabbit jejunum preparations, OeF.Cr caused a dose-dependent (0.1-3.0 mg/mL) relaxation of both spontaneous and K+-induced contractions. The calcium-channel blocking activity was confirmed when pretreatment of the tissue with OeF.Cr produced a dose-dependent shift in the Ca2+ dose-response curves to the right, similar to that produced by verapamil. Apparently, OeF.Cr was found devoid of any spasmogenic effect; however, when tested in the presence of atropine, the spasmolytic effect was potentiated, indicating the presence of spasmogenic constituent(s) of cholinergic type. The presence of the spasmogenic component was confirmed when the resultant aqueous fraction (0.1-1.0 mg/mL) caused an atropine-sensitive stimulatory effect followed by relaxation at the next higher dose (3.0 mg/mL). These results indicate that olives contain spasmolytic (Ca2+ antagonists) and spasmogenic (cholinergic) constituents, which provides a scientific base for its medicinal use in gastrointestinal disorders, such as abdominal colic, diarrhea, and constipation.