effect of zataria multiflora boiss leaf hydroalcoholic extract on rat ileum

background& objectives: zataria multiflora boiss is used in traditional medicine to treat gastrointestinal disorders and menorrhagia. the inhibitory effect of this herb on rat uterus contractions has also been reported. the aim of this study was to investigate the effect of zataria multiflora boiss hydroalcoholic leaf extract (zhle) on isolated rat ileum in presence of some known ileum stimulants. materials and methods: pieces of male and female rat ileum were mounted in an organ bath containing tyrode solution. ileum contractions were recorded by means of an isotonic transducer and results were presented in mm or percentage. ileum was precontracted by kcl, acetylcholine and bacl 2 in presence and absence of certain concentrations of zhle. results: zhle significantly reduced the contractions of the ileum precontracted by kcl (60mm), acetylcholine (0.05 μg/ml) and bacl 2 (4mm). the inhibitory effect of zhle on kcl-induced contractions was dose dependent. the inhibitory effect of zlhe on kcl-induced ileum contraction was not affected by propranolol (1μm). the stimulatory effects of these three stimulants at the mentioned concentrations were similar but the inhibitory effect for acetylcholine was stronger than other stimulants. discussion :    zhle may induce the inhibitory effect through blockage of the voltage dependent calcium channels in ileum smooth muscle. these results are compatible with those results that are reported in rat uterus. the ineffectiveness of propranolol on zlhe inhibitory effect indicates that adrenergic agonist substance (s) does not exist in the extract. it seems that there is anticholinergic substance(s) in the extract. the results support the usage of this plant in traditional medicine.