Fennel oil, and anethole in particular, has anti-flatulent properties and promotes motility of the gastrointestinal tract. In higher concentrations, antispasmodic effects occur, probably due to inhibition of calcium mobilization in the smooth muscle of the gastrointestinal tract. When the concentration of calcium in the cells decreases, relaxation of the intestinal muscles occurs, resulting in resolution of the spasm.
Other effects of fennel
Anethole also accelerates in the bronchi the beating frequency of the so-called ciliated epithelia, small cell processes responsible for the removal of mucus and foreign substances. This results in the loosening of mucus and easier expectoration.
Furthermore, anethole and fenchone are thought to help increase gastric juice secretion, stimulate appetite, and have antimicrobial effects. In very high concentrations, anethole has a toxic effect.
Side effects of fennel
In isolated cases, allergic reactions of the skin and respiratory tract have been observed. People with known allergy to celery may also be allergic to fennel fruit.
Currently, there are no known interactions with other agents.