Dryopteris, also known as wood fern and Guan Zhong, is a plant that can be seen everywhere. It is such a familiar garden ornamental plant that people seldom associate it with medicinal substances. But clinically it does come with very good therapeutic effect on a variety of diseases, such as viral influenza, fever, headache, intestinal worms, and so on. Just because of this, the U.S. Pharmacopoeia accepted it as an anthelmintic. It should be noted that Dryopteris is the one and only fern listed there.
What is Dryopteris or wood fern?
When it comes to its Chinese name of Guan Zhong, it refers to more than 30 species of plant in 6 families, according to the Traditional Chinese Medicine Dictionary. As a result, it can be very confusing sometimes. But clinically it mainly means the rhizomes with petioles of the perennial herbs of Cyrtomium frtunei J. Sm. and Dryopteris crassirhizoma Nakai in the family Dryopteridaceae, or Osmunda japonica Thunb. in the family Osmundaceae. And other similar herbs include Lunathyrium acrostichoides (Sw.) Ching, Brainia insigns (Hook.) J. Smith, Cyathea spinulosa Wall., Blechnum orientale Linn., Matteuccia struthiopteris (L.) Todaro, Woodwardia japonica (L.f.) Sm., and more.
Common name of this herb also include Dryopteris Root, Rhizoma Dryopteris, Dryopteris crassirhizoma rhizome, Cyrtomium Rhizome, male fern, buckler fern, and more. Medicinally Dryopteris crassirhizoma Nakai is the most common one and primarily produced in the mountainous area of Heilongjiang, Jilin and Liaoning provinces. It is regularly harvested in winter. And then wash clean, remove petioles and fibrous roots, dry in the sun, slice, and use raw or carbonized by stir-frying.
Dryopteris is a perennial herb, up to 1 meter in height. Rhizome is thick. Rhizome and petioles are densely covered with brown large oval-lanceolate scales. Leaves are clustered, bipinnatiparted, and with 10 to 25cm petiole and 20 to 30 pairs of accessory pinna. Sori grow in the pinna that is above the middle parts. Indusia are round, kidney-shaped, and brown.
It contains filmarone, which by decomposition get filicic acid BBB, PBB, PBP, flavaspidic acid BB, PB, AB, albaspidin AA, BB, PB, etc.
Dryopteris health benefits
This is an ordinary plant in the wild for cultivated. A long time ago it was discovered by Traditional Chinese medicine (TCM) and then used as one of healing herbs. This is simply because it has an extensive medicinal uses, for example vermifuge and antiviral drug. And its pharmacology can well illustrate its efficacy.
Modern pharmacological actions of Dryopteris root
1. The filicic acid and flavaspidic acid contained can significantly destroy or expel intestinal worms. They have strong toxicity to tapeworms and can paralyze and discharge the tapeworms. In addition, they also expel roundworms and other parasites;
2. Experiments show that it can strongly inhibit the influenza virus. What’s more, it also has relatively strong antiviral activity on adenovirus, polio virus, Japanese encephalitis virus, etc.;
3. It has hemostatic, analgesic, anti-inflammatory effect when used externally;
4. Its decoction and extract can greatly excite the rabbit uterine.
Proven rhizoma Dryopteris herbal remedies
According to Chinese pharmacopoeia, it is bitter in flavor and slightly cold and toxic in properties. And it goes to meridians of liver and stomach. Basic functions are heat-clearing and detoxifying and expelling parasite. Main Dryopteris uses and indications are abdominal pain due to parasitic infestation and sores. Charred Dryopteris root is good at stopping bleeding and often used for metrorrhagia and metrostaxis. And recommended Dryopteris dosage is from 4.5 to 9 grams in decoction.
1. Guan Zhong San. This prescription comes from Tai ping Sheng Hui Fang (Taiping Holy Prescriptions for Universal Relief). It is commonly formulated for roundworm infections, acid reflux, and non-stop pain. Other major herbal ingredients are He Shi (Common Carpesium Fruit), She Xiang (Navel Gland Secretions of Musk Deer), Long Dan Cao (Gentiana), and so on.
2. Kuai Ban San. Kuai Ban San is from Xiao Er Wei Sheng Zhong Wei Fang Lun (Treatise on Formulas for Infantile Health Care). It is exclusively designed for fast eruption of sores and measles that are red and big. Other herbs are Chi Shao (Red Peonies), Gan Cao (Licorice Root), Sheng Ma (Black Cohosh Rhizome), and Zhi Ke (Aurantium).
3. Guan Zhong Tang. This formula comes from Wan Bing Hui Chun (Recovery of Ten Thousand Diseases). It is primarily used for spitting out a great amount of blood and dying. Other two herbs are Xue Yu Tan (Crinis Carbonisatus) and Ce Bai Ye (Biota Leaves).
4. Suo Sha San. Suo Sha San is chosen from Pu Ji Fang (Prescriptions of Universal Relief). It is mainly used for bone sticking. Rest two herbs include Suo Sha Ren (Cardamom Seed) and Licorice Root.
Dryopteris side effects and contraindications
Stems and roots of Dryopteris contain a variety of phloroglucinol derivatives that have certain toxicity. Filicic acid works mainly on the digestive system and the central nervous system. As a result, large doses can damage the optic nerve, and thus cause blindness and damage to cerebral white matter. Main poisoning symptoms include headache, dizziness, diarrhea, abdominal pain, difficulty breathing, yellow vision or temporary blindness in mild cases and delirium, coma, jaundice, renal damage, limb rigidity, paroxysmal convulsions, and even death due to breathing failure in severe cases. After poisoning the recovery is rather slow and it may lead to permanent blindness. And from the perspective of TCM, this herb is considered slightly poisonous so that it shouldn’t be used in large dosage. Besides, avoid greasy food when taking it and use it with care during pregnancy and in the case of deficiency-cold in spleen and stomach.