Background: In spite of the use of industrially prepared drugs for control of diarrhea complications, the attempts to find plants that reduce intestinal smooth muscle motility are going on. The plant celery (Apium Graveolens) from Apiaceae with both nutritional and pharmacological properties contains flavonoids and has hypotensive, antinociceptive, anti- inflammatory and diuretic effects. The aim of the present study was to investigate the antispasmodic effect of celery leaf extract on the rat ileum.

Materials and Methods: Celery leaf powder was extracted by maceration in 70% alcohol for 72 hours. A terminal portion of ileum from Wistar male rat was dissected and its contractions were recorded isotonically under one gram tension in an organ bath containing Tyrode solution. t-test, and one and two-way ANOVA were used to compare the results.

Results: Extract cumulative concentrations (0.25, 0.5, 1, 2 and 4 mg/ml) reduced the ileum contractions induced by KCl (60 mM) and carbachol (10 μM) dose-dependently (ANOVA, P<0.0001). The antispasmodic effect of extract was not reduced by tissue incubation with propranolol (1 μM, 30 min), naloxone (1 μM, 30 min), L-NAME (100μM, 20 min), glibenclamide (10 μM, 5 min) and tetraethylammonium (1 mM, 5 min). In Ca²⁺-free with high K⁺ (60 mM) Tyrode solution, the extract (1mg/ml) reduced the ileum contractions induced by cumulative concentrations of CaCl₂ (5-8 mM) dose-dependently (two way ANOVA, P<0.0001).

Conclusion : Celery leaf extract inhibited the ileum contractions dose dependently. It seems that voltage dependent calcium channels and receptor-operated calcium channels are involved in this activity, but β-adrenoceptors, opioid receptors, NO, and potassium channels are not involved in this effect. It is possible that apigenin as the celery flavonoid is responsible for this activity.