Last week I took some time to share some information specifically about the research on the essential oil component trans-anethole ((E)-anethole). This week I am going to recap some of the therapeutic properties, safety considerations, and essential oils it is found in as well as go more in depth with information about Sweet Fennel (Foeniculum vulgare dulce) and Anise (Pimpinella anisum).
What are the therapeutic properties of oils rich in trans-anethole?
- Antispasmodic: Relaxing effect on muscles (think cramping)
- Analgesic: for the colon, the genito-urinary tract, and the muscles associated with them. (Fennel can be used for menstrual cramps, but may cause more bleeding.)
- Carminative: Relates to its capacity for digestive support.
- Anti-inflammatory: reduce inflammation
- Anti-coagulant: prevents blood clotting
Are there any safety considerations?
YES! Below are just few that should always be kept in mind when using essential oils high in trans-anethole.
- Trans-anethole raises toxicity concerns (hepatotoxic, genotoxic, and neurotoxic).
- Avoid using oils with these constituents during pregnancy and lactation.
- Avoid using in children that are five or younger.
- Should be avoided by individuals with blood clotting diseases or those on blood thinners.
- Should be avoided by those having major surgery.
- Oils high in ethers should never be used long term. It's best to use them only for a few days.
What essential oils contain a high percentages of trans-anethole?
There are literally only a handful, but they are important to know due to the safety concerns associated with trans-anethole. I also want to point out the importance of knowing the botanical names and subspecies. This will help you to determine what essential oil you actually are using.
This can be particularly important if you are creating topical blends and need to use a specific dilution. For example bitter fennel has a recommended 1.8% dilution ratio where sweet fennel has a 2.5%. In this instance, you would also need to know the subspecies for the bitter fennel to determine which dilution rate you are using.
- Anise (Pimpinella anisum)
- Anise (star), (Illicium verum)
- Fennel (bitter), (Foeniculum vulgare) subsp. Capillaceum
- Fennel (sweet), (Foeniculum vulgare dulce)
- Myrtle (aniseed), (Backhousia anisata)
How does the information about trans-anethole relate to essential oils?
When looking at a few essential oils like sweet Fennel and Anise, we can list a few potential therapeutic actions that can be related to the research found regarding the component trans-anethole. Then we can look at the potential applications and begin to understand how it all fits together.
FENNEL (Foeniculum vulgare dulce):
Potential Therapeutic Properties related to trans-anethole
- Anti-inflammatory: Trans-anethole has anti-inflammatory properties
- Antibacterial: Fennel oil is active against a wide range of organisms, including Gram-positive and Gram-negative bacteria. Trans-anethole is an active constituent.
- Antiemetic: There is anecdotal evidence (not scientific) suggesting that the essential oil can reduce the severity of nausea and vomiting. I actually created a blend last March or April that worked quite well for this for myself.
- Antifungal: Sweet Fennel oil has antifungal activity notably active against Candida albicans due to the trans-anethole content.
- Antispasmodic: Sweet Fennel oil has a direct, relaxing effect on the uterine muscle from containing substantial amounts of trans-anethole, which is credited with antispasmodic actions.
- Carminative: Traditional medicine makes use of Fennel seeds’ antispasmodic and carminative properties.
- Emmenagogue: Trans-anethole potentially has estrogenic effects, and has antiplatelet activity, a clot destabilizing effect and vasorelaxant action. It should be used with caution by women who have a heavy menstrual flow.
Potential Clinical Applications based on trans-anethole composition:
- Digestion: Fennel is a great digestive aid. It helps to relieve nausea, flatulence, indigestion, and general digestive discomfort. It can also be used to decrease appetite (this is one of its traditional uses).
- Menstruation: Fennel is a useful oil in blends for cramps. However, it is not suited for those who experience heavy bleeding. Many women experience fluid retention and bloating around the time of and during menstruation, and it can be used to combat this, as it is an effective light diuretic.
- Respiratory: Fennel has antispasmodic effects, which can aid with respiratory problems such as bronchial spasm and cough. Its antibacterial, mucolytic actions make it useful for infections and congestion.
- Skin: Fennel can be used in topical blends to combat superficial fungal infections.
ANISE (Pimpinella anisum):
Potential Therapeutic Properties related to trans-anethole:
- Analgesic: Observed pain relieving effects are possibly related to its anti-inflammatory and antispasmodic actions.
- Anti-inflammatory: Trans-anethole can alleviate inflammation.
- Antispasmodic: Trans-anethole has antispasmodic actions on both smooth and skeletal muscle (Albuquerque et al. 1995 cited by Bowles 2003).
- Antithrombotic: Trans-anethole has anti-platelet, clot-destabilizing, and vasorelaxant actions.
- Antiviral: Anise is active against Herpes Simplex Virus Type II.
- Carminative: It offers antispasmodic activity. This relates to its capacity for digestive support.
- Digestive aid: Anise is traditionally used to stimulate and support digestive processes.
- Emmenagogue: This action is probably attributed to Anise so often because of the possible estrogenic activity (trans-anethole). Additionally, the anti-platelet, clot destabilizing, and vasorelaxant actions could increase menstrual blood flow.
- Expectorant: Like Sweet Fennel, the penetrating properties of Anise appear to reduce the viscosity of mucus. This, as well as its antispasmodic and anti-inflammatory actions, means it can benefit cases of respiratory congestion
Potential Clinical Applications based on trans-anethole composition:
- Digestive discomfort: Anise seed is known to promote digestion and to have an antispasmodic effect. A few drops of Anise can be used in massage oil blends for individuals who complain of digestive pain. It can also be used with Peppermint and Ginger for reducing nausea. NOTE: It is important to remember to avoid Anise with pregnant women. See the safety review above.
- Respiratory: Another great use of this oil is for a spasmodic cough due to a cold or the flu. It can be blended with oils high in esters, such as Roman Chamomile or even Clary Sage, for a its antispasmodic actions. It also blends well with Ginger for respiratory support.
- Menstrual concerns: Anise can potentially stimulate menstrual flow and alleviate the perception of discomfort through trans-anetholes anti-inflammatory, analgesic, and antispasmodic actions. BUT is should not be used by individuals who experience heavy bleeding.
I hope this information is informative and educational. Should you have any questions, please feel free to reach out to me.