Methyl chavicol, also called estragole or isoanethole, is a phenol methyl ether found in basil, fennel, ravensera, star anise, anise, and tarragon.
- Methyl chavicol may be carcinogenic in high doses, and the IFRA has a limit on amounts permitted in products sold. Certain chemotypes of basil, ravensara, and tarragon can have over 80% methyl chavicol. From: Clarke, S. (2009). Essential chemistry for aromatherapy. Elsevier Health Sciences.
Phenol methyl ethers are similar to phenols, but even more powerful. Concerns with overuse include psychotropic, neurotoxic effects, liver toxicity, genotoxic, and possible carcinogenic activity.
Links to Plants Containing Estragole
The listings of research below represents a compilation of scientific articles found on the topic, with a very brief overview description of each article/study. This compilation of research articles does not necessarily imply that there are adequate results to demonstrate safe and/or effective human use of any herb listed.
- With constituents of methylchavicol (47%), geranial (19%) and neral (15%), Ocimum basilicum (basil) oil had radical scavenging and antioxidant activities and may be usable in treating oxidative damage and stress from certain inflammatory conditions. From: Kavoosi, G., & Amirghofran, Z. (2016). Chemical composition, radical scavenging and anti-oxidant capacity of Ocimum Basilicum essential oil. Journal of Essential Oil Research, 1-11. Link: http://dx.doi.org/10.1080/10412905.2016.1213667
- Both basil and its estragole constituent demonstrated anti-inflammatory activity, with the essential oil more effective than the constituent for acute and chronic anti-inflammatory action. From: Rodrigues, L. B., Martins, A. O. B. P. B., Cesário, F. R. A. S., e Castro, F. F., de Albuquerque, T. R., Fernandes, M. N. M., … & Barbosa, R. (2016). Anti-inflammatory and antiedematogenic activity of the Ocimum basilicum essential oil and its main compound estragole: In vivo mouse models. Chemico-Biological Interactions, 257, 14-25. Link: http://dx.doi.org/10.1016/j.cbi.2016.07.026
ANTIMICROBIAL / ANTIFUNGAL / ANTIBACTERIAL
- Basil (Ocimum basilicum) essential oil showed activity against eight important postharvest deteriorating fungi with the following constituents being significant: 1,8-cineole, linalool, camphor, α-terpineol, methyl chavicol, and eugenol. From: Barcelos, R. C., Jham, G. N., Dhingra, O. D., Mendonca, F. A., & Valente, V. M. (2013). Identification and Quantification of the Major Fungitoxic Components of the Brazilian Basil (Ocimum basilicum L.) Essential Oil. Journal of Food Research, 2(5), 124.
- Antibacterial abilities of 96 essential oils and their constituents were assessed. Marigold, ginger, jasmine, patchouli, gardenia, cedarwood, carrot seed, celery seed, mugwort, spikenard, and orange bitter oils along with the constituents of cinnamaldehyde, estragole, carvacrol, benzaldehyde, citral, thymol, eugenol, perillaldehyde, carvone R, and geranyl acetate were strongest against C. jejuni. Those most active against E. coli were oregano, thyme, cinnamon, palmarosa, bay leaf, clove bud, lemon grass, and allspice oils and the constituents: carvacrol, cinnamaldehyde, thymol, eugenol, salicylaldehyde, geraniol, isoeugenol, citral, perillaldehyde, and estragole. Those most active against L. monocytogenes were gardenia, cedarwood, bay leaf, clove bud, oregano, cinnamon, allspice, thyme, and patchouli and the constituents of cinnamaldehyde, eugenol, thymol, carvacrol, citral, geraniol, perillaldehyde, carvone S, estragole, and salicylaldehyde. Those most active against S. enterica were thyme, oregano, cinnamon, clove bud, allspice, bay leaf, palmarosa, and marjoram oils as well as thymol, cinnamaldehyde, carvacrol, eugenol, salicylaldehyde, geraniol, isoeugenol, terpineol, perillaldehyde, and estragole. From: Friedman, M., Henika, P. R., & Mandrell, R. E. (2002). Bactericidal activities of plant essential oils and some of their isolated constituents against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica. Journal of Food Protection®, 65(10), 1545-1560.
- Antibacterial, antifungal, and antiviral, antiradical activities of the whole essential oil, and of the constituent isochavicol were investigated and an antiplasmodial activity of isochavicol was noticed. From: Lanfranchi, D. A., Laouer, H., El Kolli, M., Prado, S., Maulay-Bailly, C., & Baldovini, N. (2010). Bioactive phenylpropanoids from Daucus crinitus Desf. from Algeria. Journal of agricultural and food chemistry, 58(4), 2174-2179
- Insecticidal activity against Sitophilus oryzae, Callosobruchus chinensis and Lasioderma serricorne was demonstrated by fennel and its constituents: anethole, estragole, and fenchone. From: Kim, D. H., & Ahn, Y. J. (2001). Contact and fumigant activities of constituents of Foeniculum vulgare fruit against three coleopteran stored‐product insects. Pest Management Science, 57(3), 301-306.
- Total phenol content of essential oils was related to LDL antioxidant activity associated with cardiac heart disease. Phenols included: methylchavicol, anethol, p-cymen, apiole, cinnamic ether, carvacrol, thymol, p-cymene, vanillin, cuminol, and eugenol. From: Teissedre, P. L., & Waterhouse, A. L. (2000). Inhibition of oxidation of human low-density lipoproteins by phenolic substances in different essential oils varieties. Journal of Agricultural and Food Chemistry, 48(9), 3801-3805.
By: Kathy Sadowski