True worm fern

The True worm fern (Dryopteris filix-mas) is a native representative of the ferns and belongs to the family of wood ferns (Dryopteridaceae). It prefers to grow in shady forests, at forest edges, and on moist soils and is easy to recognize by its large, doubly pinnate fronds. As early as antiquity, the worm fern was valued for its medicinal properties – especially as a remedy against intestinal parasites.

Over the centuries, it found use above all in traditional European herbal medicine. Today, the True worm fern is used only with caution due to its supposedly potent but also possibly potentially toxic constituents – nevertheless, its historical and pharmacological value is undisputed.

What health benefits does the True worm fern offer?

In traditional medicine, the True worm fern was used for various purposes. Scientific investigations likewise point to a therapeutic potential; however, the studies are not readily transferable, and the results should therefore be interpreted critically. Here are both the results of current studies and traditional areas of application:

  • Anthelmintic effect: The worm fern was traditionally used to combat tapeworms and other intestinal parasites. Its rhizomes contain substances that, according to scientists, could potentially paralyze the parasites so that they could be excreted (1,2).
  • Anti-inflammatory properties: In low doses, the extract was also used externally for skin inflammation or hemorrhoids. Studies likewise point to an anti-inflammatory potential(3,4).
  • Tonic in folk medicine: In some regions, the worm fern was considered a general strengthening remedy for weakness and exhaustion – although modern medicine refrains from this.

How does the True worm fern work in the body?

The medicinal effect is presumably attributable to various constituents. Among them, above all filicin (5). However, exactly how the plant works has not yet been sufficiently researched to be able to make conclusive statements here.

Are there risks or side effects?

Yes – and these should not be underestimated. The use of the worm fern should take place exclusively under expert guidance:

  • Toxicity: In higher doses, the active substances can damage the central nervous system and lead to vomiting, convulsions, or even respiratory paralysis (2,3,4,6).
  • Not suitable for children or pregnant women: Intake is strictly contraindicated for pregnant women, breastfeeding mothers, and children.
  • Outdated use: Due to its high risk potential, the True worm fern is hardly ever used internally today – modern antiparasitics are safer and more effective.

Conclusion

The True worm fern is a fascinating medicinal plant with a long tradition, especially as a natural remedy against worms. Despite its supposed effect, it should nowadays only be used with the greatest caution. In modern phytotherapy, it now plays only a subordinate role due to its toxicity – but remains significant as part of the history of herbal medicine.

Sources:

  1. Prajapati, D., Jadon, A., Purohit, K. (2022). Evaluation of anthelmintic activity of Dryopteris filix-mas using earthworm. World Journal of Advanced Research and Reviews, 16, 886–893. https://doi.org/10.30574/wjarr.2022.16.1.1093
  2. Egorova, A., Gatiyatullina, A., Terenzhev, D., Belov, T., & Kalinnikova, T. (2021). Toxic action of substances from male fern Dryopteris filix-mas (L.) Schott (1834) on free-living soil nematode Caenorhabditis elegans Maupas (1900). E3S Web of Conferences, 254, 09011. https://doi.org/10.1051/e3sconf/202125409011
  3. Erhirhie, E. O., Emeghebo, C. N., Ilodigwe, E. E., Ajaghaku, D. L., Umeokoli, B. O., Eze, P. M., Ngwoke, K. G., & Chiedu Okoye, F. B. G. (2019). Dryopterisfilix-mas (L.) Schott ethanolic leaf extract and fractions exhibited profound anti-inflammatory activity. Avicenna journal of phytomedicine, 9(4), 396–409.
  4. Erhirhie, E. O., Emeghebo, C. N., Ilodigwe, E. E., Ajaghaku, D. L., Umeokoli, B. O., Eze, P. M., Ngwoke, K. G., & Chiedu Okoye, F. B. G. (2019). Dryopterisfilix-mas (L.) Schott ethanolic leaf extract and fractions exhibited profound anti-inflammatory activity. Avicenna journal of phytomedicine, 9(4), 396–409.
  5. Franchi, G. G., & Ferri, S. (1988). Localization of the active principles of the male fern (Dryopteris filix-mas (L.) Schott.) by fluorescence microscopy. Pharmacological Research Communications, 20(Suppl. 5), 135–138. https://doi.org/10.1016/S0031-6989(88)80858-0
  6. Aronson, J. K. (Ed.). (2016). Dryopteraceae. In Meyler's side effects of drugs (16th ed., p. 1100). Elsevier.[ https://doi.org/10.1016/B978-0-444-53717-1.00670-3