Spasmolytic Effect of Stachys Lavandulifolia Vahl. Crude Methanolic Extract and Fractions on Rat Ileum

The aim of this study was to investigate the effect of aerial parts of Stachys lavandulifolia Vahl. extract on the rat ileum contractions. The crude extract was prepared by maceration method (90% methanol) followed by fractionating into chloroform, ethyl acetate, petroleum ether and water. In adult male Wistar rats, ileum was sectioned and mounted in tissue bath and their contractility was recorded isotonically. KCl (60 mM)-induced ileum contractions were attenuated by crude extract and its fractions. The most potent fraction was chloroformic fraction (CF) with IC50 = 0.126 ± 0.018 mg/mL. In calcium-free Tyrode solution with high K+, the CF (0.01 - 0.04 mg/mL) attenuated CaCl2-induced contractions (p < 0.001). The CF (0.05-0.8 mg/mL) attenuated the carbachol-induced contraction (p < 0.001). The CF antispasmodic effect was reduced by naloxone (as a non-selective opioid antagonist), not by propranolol and L-NAME as β-adrenoceptors antagonist and nitric oxide synthase inhibitor respectively. It was concluded that S. lavandulifolia can inhibit ileum contractility mainly via disturbing the calcium mobilization and partly by opioid receptors’ activation. Our results may support the traditional usage of this herb for treating diarrhea.