Inhibitory effect of hydroalcoholic and flavonoids extracts of Dracocephalum kotschyi, and its components luteolin, apigenin and apigenin-4’-galactoside on intestinal transit in mice

Introduction: Dracocephalum kotschyi is an Iranian indigenous herbal plant which has been reported to have antispasmodic activity in vitro. The antispasmodic activity of hydroalcoholic extract of D. kotschyi is reported to be due to its flavonoids constituents including apigenin and luteolin. The objective of this research was to compare antispasmodic activities of hydroalcoholic and flavonoids extracts of D. kotschyi on ileum contractions in vivo. In addition, spasmolytic activity of apigenin, luteolin and apigenin-4'-galactoside were compared. Methods: The hydroalcoholic extract was prepared by percolation method. Flavonoids extract was obtained by solvent-solvent extraction. Antispasmodic effect of the test compounds was assessed by measurement of percent small intestine transit following oral administration of a charcoal meal and compared with control group and standard drug loperamide. Results: Biochemical assessment of flavonoids content of the extracts showed that ethyl-acetate fraction contained higher quantity of flavonoids. Loperamide (2.5 mg/kg) reduced charcoal meal movement by 58% in comparison to control group. Hydroalcoholic extract of D. kotschyi (20 mg/kg) and its ethyl-acetate fraction (20 mg/kg) reduced the intestinal charcoal meal transit by 32% and 90%, respectively. Apigenin, luteolin and apigenen-4'-galactoside with oral dose of 20 mg/kg inhibited intestinal movement of the charcoal meal 93%, 89% and 45%, respectively in comparison with the vehicle treated control groups. Conclusion: This study confirms that both the hydroalcoholic and flavonoids extracts of D. kotschyi have antispasmodic properties in vivo. Antimotility of apigenen-4'-galactoside in mice is probably due to release of apigenin in the gastrointestinal tract