Polypodium vulgare, commonly known as the common polypody, is an evergreen fern. It grows up to 0.3 meters (1 foot) by 0.3 meters (1 foot). This plant is native to northern Europe, the Mediterranean, temperate Asia, and parts of the USA.
It is frequently found in shaded and semi-shaded locations, often growing on rocks, old walls, tree bases, and in rocky undergrowth. The fern prefers well-drained, acidic, sandy soils, but can also grow in loam and chalk with moist conditions. Its fronds are typically triangular, up to 50 cm long, and composed of triangular leaflets.
Active Compounds and Mechanisms
Polypodium vulgare contains several bioactive compounds, including ecdysteroids, flavonoids, and phenolic acids. These compounds contribute to the fern’s biological activities. Ecdysteroids are plant steroids that offer protection against plant-eating insects.
Flavonoids and phenolic acids are also present in Polypodium vulgare, with various phenolic compounds identified in its fronds. These compounds are known for their antioxidant properties, which help protect cells from oxidative damage caused by unstable molecules called free radicals. They also exhibit anti-inflammatory effects. The European Medicines Agency recognized the rhizome of P. vulgare in 2008 for use as an expectorant in cough and cold remedies, and for occasional constipation.
Health Applications
Polypodium vulgare has been explored for various health applications, particularly in immune system support and potential cognitive benefits. Extracts from a related fern, Polypodium leucotomos (PLE), have shown promise in managing skin issues like psoriasis, vitiligo, and atopic dermatitis, and exhibit photoprotective properties against UV radiation.
The fern’s immunomodulatory properties suggest its potential to support the immune system. Research indicates that Polypodium vulgare can inhibit UV-induced generation of reactive oxygen species, contributing to its protective effects against sun damage. The extract has been observed to prevent cellular damage associated with UV exposure and aging, while also stimulating the production of new skin proteins. Beyond skin health, traditional uses of P. vulgare include addressing liver ailments, respiratory conditions, and supporting cognitive function, though more research is needed in these areas.
Usage and Safety
When considering its use, Polypodium vulgare is available in various forms, including extracts, capsules, and teas. It is generally recommended to follow manufacturer’s dosing protocols. Consulting a healthcare professional is advisable for personalized guidance, especially for specific health concerns.
Dermatitis has been reported as a common side effect from contact with the plant’s leaves. There is limited reliable information on its safety during pregnancy and breastfeeding, so avoidance is advised during these periods. Polypodium vulgare has not been found to have severe interactions with other drugs. However, it might influence how quickly the liver breaks down certain medications, potentially altering their effects.