Spasmolytic activity of essential oil and various extracts of Ferula gummosa Boiss. on ileum contractions.

Traditional herbal medicines such as Ferula gummosa Boiss. have been used for treatment of intestinal disorders in Iran. To date no pharmacological evidence for their effectiveness has been reported. The aim of this study was to examine the relaxant effect of essential oil, hydro-alcoholic, etheric, petrolic and methanolic extracts of Ferula gummosa and two of its components, alpha-pinene and beta-pinene, on isolated rat ileum contractions induced by KCl and acetylcholine (ACh). Ferula gummosa essential oil (FGEO) and hydro-alcoholic, etheric, petrolic and methanolic extracts all inhibited the response to 80 mM KCl in a concentration-dependent manner and attenuated the maximum attainable response of the ACh concentration-response curve. Although the effect of etheric extract on ACh contractions was less than that of petrolic extract, the overall order of effectiveness on the weight basis was the etheric, petrolic, methanolic, and hydro-alcoholic extracts, and the essential oil, respectively. A mixture of etheric and petrolic extracts together had a similar effect on KCl response to etheric extract was used alone. Alpha-pinene and beta-pinene both exhibited inhibitory effect on the contraction of rat ileum, but the inhibitory effect of beta-pinene on KCl contraction was more pronounced. The inhibitory effect of a mixture of these two compounds was, however, less than the sum of their separate effects. When a mixture of alpha-pinene and beta-pinene together were examined on the ileum, without presence of the spasmogen, they initially caused contraction of the tissue, while neither of them used alone caused a noticeable contraction of the ileum. This study shows that Ferula gummosa essential oil and its various extracts are relaxant of rat isolated ileum and that at least part of their inhibitory effect is due to alpha-pinene and beta-pinene components. As the inhibition of contractile over-activity of the ileum is the basis of the treatment of some gastero-intestinal disorders such as diarrhea, Ferula gummosa may have clinical benefits for treatment of this condition.