Background: Achillea is a plant widely used in traditional medicine for gastrointestinal disorders. There are some reports on gastrointestinal effects of Achillea, such as antiulcer, antibacterial, hepatoprotective, choleretic, and antispasmodic. To investigate the effects of aqueous-ethanol extract of Achillea wilhelmsii on rat's gastric acid output in basal, vagotomized (VX), and vagal-stimulated conditions.
Materials and methods: 24 male Wistar rats were randomly divided into 2 groups: control and test. Gastroduodenostomy was performed for each rat. Gastric content was collected for 30 min by washout technique. One milliliter of 3 doses (0.5, 1, and 2 mg/kg) was introduced into the stomach of each rat in the test group and the same volume of saline was used in the control group. Total titratable acid was measured by a titrator.
Results: The extract inhibited acid output significantly in basal condition by 1 and 2 mg/kg doses (P < 0.05) but in VX condition this inhibitory effect on acid output disappeared and the 1 and 2 mg/kg doses increased acid output significantly (P < 0.05 and P < 0.001, respectively). The extract showed a reduction in the acid output in vagal-stimulated condition by 1 and 2 mg/kg doses, which were not statistically significant.
Conclusion: These results showed an inhibitory effect of A. wilhelmsii extract on acid output in basal condition. The inhibitory effect of the extract was exerted via gastric vagal parasympathetic nerve.
Keywords: Achillea wilhelmsii; gastric acid; vagotomy; vagus nerve.