Effects of an Atractylodes lancea rhizome extract and a volatile component β-eudesmol on gastrointestinal motility in mice

The rhizomes of Atractylodes lancea DC (Compositae) are used clinically to treat gastrointestinal symptoms, including functional dyspepsia and gastroparesis, in China and Japan, but their influence and mechanism on gastrointestinal motility are not yet proven in detail. This study examined the effects of an Atractylodes lancea extract, and isolated β-eudesmol, on gastric emptying and small intestinal motility in atropine-, dopamine-, and 5-hydroxytryptamine (5-HT)-treated mice. The extract (500 or 1000 mg/kg) and β-eudesmol (50 or 100 mg/kg), as well as itopride hydrochloride (a dopamine D2 receptor antagonist, 10 or 50 mg/kg), stimulated small intestinal motility in normal mice. They inhibited reductions in gastric emptying and gastrointestinal motility induced by dopamine (1 mg/kg, intraperitoneal injection, ip). The extract (1000 mg/kg) and β-eudesmol (100 mg/kg) inhibited the atropine-induced decrease in small intestinal motility, but not gastric emptying. Furthermore, the extract (500 or 1000 mg/kg) and β-eudesmol (25, 50, or 100 mg/kg) inhibited reductions in gastric emptying and small intestinal motility caused by 5-HT (4 mg/kg, ip) or the 5-HT3 receptor agonist 1-(3-chlorophenyl) biguanide (0.5 mg/kg, ip), but not a 5-HT2C receptor agonist. These findings suggest that the extract of Atractylodes lancea and β-eudesmol may stimulate gastric emptying or small intestinal motility by inhibiting the dopamine D2 receptor and 5-HT3 receptor.