Maidenhair fern

Other Names

AdiantoAdiantum aethiopicumAdiantum aleuticumAdiantum capillusAdiantum capillus-venerisAdiantum capillus-veneris var. modestumAdiantum capillus-veneris var. protrusumAdiantum capillus-veneris var. rimicolaAdiantum cuneatumAdiantum micheliiAdiantum modestumAdiantum pedatumAdiantum pedatum var. aleuticumAdiantum raddianumAdiantum schaffneriAdiantum tenerumAlambrilloAleutian maidenhairAvencaBarezeBarsioshanBarunBlack maidenhair fernCabello de venusCapileraCilantrilloCommon maidenhairCommon maidenhair fernCulandrilloCulantrilloCulantrillo de pozoDelta maidenhair fernDumtuliFern karn damFive-finger fernFive-fingered fernFrauenhaarHair of VenusHansapadiHansarajaHansrajHerba capillorum venerisIwa'iwaKazbaratul BerKizberet el-bîrKuzburat-el birLady fernMaiden fernMaria's fernMubarakaNorthern maidenhair fernOur Lady's hairPare-siavashanParesiyanwashanPurshaQeyteranRock fernSeruppadaiShaar-ul-jibalShaar-ul-jinShaarul-arzSouthern maidenhair fernVenus hair fernVenus maidenhair fernWestern maidenhair fernXaleresXencerok

Synopsis

Maidenhair Fern (Adiantum capillus-veneris L.)

1. Identity and Botanical Description

Taxonomic Classification and Nomenclature

Adiantum capillus-veneris, commonly known as the maidenhair fern, southern maidenhair fern, black maidenhair fern, and Venus hair fern, is a species of fern in the genus Adiantum and the family Pteridaceae, with a subcosmopolitan worldwide distribution. The genus name derives from the Greek word adiantos, meaning "unwetted," in reference to the water-repellent foliage, while the specific epithet comes from Latin meaning hair (capillus) of Venus (veneris).

Common names in various languages include: maidenhair fern, true maidenhair, southern maidenhair, Venus hair fern, ladies hair, avenca, adianto, barun, fern karn dam, Frauenhaar, and herba capillorum veneris. In Iranian Traditional Medicine it is known as Pare-siavashan. In Ayurvedic and Unani traditions it is referred to as Hansraj or Banpasha. Botanical synonyms include Adiantum capillus, A. michelii, A. modestum, and A. tenerum.

Morphology and Distribution

Adiantum capillus-veneris is a tufted fern belonging to the Pteridaceae family, widely grown in warm-temperate to tropical climates with high moisture content; it is a hardy, up to 35 cm high plant with an aromatic fragrance and a creeping rhizome. The plant fronds are generally double-rowed, tender, glabrous, and grow up to 50 cm long; it has a glossy black petiole and is coated with hair at the base, and the species has an ovate to oblong-ovate leaf blade.

The medicinal parts are the fronds, rhizomes, and roots. The plant is widely distributed across Southern Europe, the Atlantic coast as far as Ireland, the southern Alpine valleys, Central and South America, Australia, and Iran. The fern is listed as an endangered species in North Carolina and as a threatened species in Kentucky, due to loss of Appalachian habitat.

Medicinal Parts and Common Preparations

The fronds of maidenhair fern were mainly administered by ancient physicians as a single medicine or in combination with other plants in multi-herbal formulations for curing different diseases. The European species is used in preparing a syrup called Sirop de capillaire, which is popular in France and Germany as a mucilaginous pectoral; the plants yield their virtues to boiling water and are used in decoction, infusion, or syrup. In contemporary use, preparations include dried herb teas, fluid extracts, tinctures, powders, and topical ointments.

2. Traditional and Historical Use

Ancient Greece and Rome

In European herbal medicine, the use of this plant dates back to the era of the Greek physicians Pedanius Dioscorides and Gaius Plinius Secundus (Pliny, 23 A.D. to 79 A.D.). In ancient Greek and Roman medicine, Dioscorides and Galen documented its use for spleen pain, kidney stones, jaundice, and as a hair growth stimulant. The ancient Greeks prepared the fern into an herbal tea and used it as an expectorant in treating coughs.

Medieval European Herbalism

The fern was also used by medieval herbalists, who administered maidenhair fern to patients with severe respiratory conditions such as pleurisy. European herbal practitioners during the Middle Ages commonly used this plant to treat scalp and hair conditions; its reputation for promoting hair growth and supporting healthy scalp conditions led to its regular inclusion in hair rinses and topical ointments. In the traditions recorded in early American eclectic medicine, maidenhair was classified as refrigerant, expectorant, tonic, and subastringent, with decoction noted for use in febrile diseases, erysipelas, coughs, chronic catarrh, hoarseness, influenza, and asthma.

Iranian Traditional Medicine (ITM)

Maidenhair fern has been frequently used in Iranian Traditional Medicine for different medicinal aspects and was well known for thousands of years. Information on the plant was collected by ancient physicians in classic ITM texts including Qanun fi al-Teb, Tohfat-ul-momenin, Makhzan-ol-Advieh, Zakhireh Kharazmshahi (Treasures of the Khwarazm Shah), Qarabadin kabir, Qarabadin Shafaie, and Exir Azam (Great Elixir).

Specific traditional ITM indications documented across these classical texts include: oral application of the fronds decoction for cleansing the respiratory system, dyspnea, asthma, coryza, and chest pain; topical eye drops to control fistula lacrymalis; and oral powders for gastrointestinal disorders such as jaundice, diarrhea, and abdominal cramps. It was reported as useful for dissolving kidney calculi and as a diuretic; as a powerful anti-inflammatory agent applied topically in ointment form on fistula; and Persian physicians administered oral decoction for female genital disorders such as amenorrhea, and to help facilitate childbirth and extraction of the placenta. Maidenhair fern was also used as a potent hair tonic for alopecia, hair growth, and dandruff.

According to ITM, maidenhair fern was prescribed as a single medicine or in poly-herbal formulations for the treatment of many diseases, and among them respiratory and urogenital diseases were the most important ones. Among the plants most commonly combined with maidenhair fern in traditional multi-herbal formulations were liquorice, celery, fennel, sweet violet, stavesacre, marshmallow, caltrop, and hyssop.

Ayurvedic and South Asian Traditions

The plant is used in the Ayurvedic system of medicine for certain health conditions such as cold, tumors of the spleen and liver, skin diseases, bronchitis, and inflammation. In India, under Ayurvedic practices, it has been utilized to treat respiratory disorders, fever, and digestive issues. Ethnomedicinally, the species has been used as a tonic and diuretic; in the treatment of cold, fever, cough, and bronchial disorders; as a stimulant, emollient, purgative, demulcent, and general tonic; and in hair tonic and skin disease preparations.

Chinese Traditional Medicine

In ancient Chinese medicine, Adiantum capillus-veneris was used as a remedy for bronchitis, skin diseases, nephritis, and as a diuretic, among other applications — illustrating the broad therapeutic uses of this herb across different cultural traditions — and its use in Chinese medicine has been a common practice since ancient times.

Middle Eastern and Other Regional Uses

In Middle Eastern countries such as Iraq, it was a traditional practice to use the rhizome for coughing and pertussis. It was used in Iranian traditional medicine for treating respiratory tract diseases, irregular menstruation, flatulence, jaundice, splenomegaly, and scrofula. In contemporary Brazilian herbal medicine, the leaf and fronds are used to treat coughs, hair loss, laryngitis, bronchitis, dryness of the throat, to augment digestion and appetite, regulate menstruation, promote the functioning of the renal system, and ease childbirth. This plant is also used medicinally by Native Americans.

3. Key Constituents and Active Compounds

Overview of Phytochemical Profile

The plant is rich in important phytochemicals including triacylglycerols, phospholipids, carotenoids, chlorophylls, phenolic acids, flavonoids, phytosterols, terpenoids, and volatile organic compounds. Systematic phytochemical studies on the whole plant material have resulted in the isolation and structure elucidation of many compounds including triterpenoids, flavonoids, phenylpropanoids, oleananes, alicyclic compounds, and carotenoids.

Flavonoids

Flavonoids represent one of the dominant and pharmacologically relevant compound classes in the plant. Yuan et al. (2012) identified seven bioactive compounds, including 3-coumaroylquinic acid and kaempferol-3-glucosides as the major phenolic compounds. The plant contains flavonoids such as rutin and isoquercetin, as well as triterpenoids and mucilage, all of which exhibit antioxidant and anti-inflammatory properties. Adiantum leaf extracts contain a high level of flavonoids and were found to be a good source of antioxidants.

Terpenoids and Triterpenoids

Triterpenoids and flavonoids are the major compounds identified in maidenhair fern. Reddy et al. (2001) isolated a new terpenoid, 22,29-epoxy-30-norhopan-13-ol, from Adiantum leaves, which showed strong antibacterial activity. These include adiantane-type and filicane-type fern-specific triterpenoids, as well as oleanane-type compounds.

Tannins, Saponins, and Other Phenolics

Phytochemical analysis confirmed the presence of flavonoids, alkaloids, tannins, saponins, cardiac glycosides, terpenoids, steroids, and reducing sugars. Compounds such as chlorogenic acid and rutin, which are abundant in A. capillus-veneris, exhibit well-established wound-healing, anti-inflammatory, and antioxidant properties.

Essential Oil Constituents

The plant's essential oil fraction contains compounds including carvacrol, carvone, hexahydrofarnesyl acetone, thymol, n-nonanal, hexadecanoic acid (palmitic acid), and phytol. The antioxidant property of the essential oil is attributed to phytoconstituents such as carvone, carvacrol, and thymol.

Mucilages and Other Constituents

Historical sources note that the maidenhair ferns contain a volatile oil, sugar, tannin, mucilage, and a bitter principle. The mucilaginous fraction is considered particularly relevant to the plant's traditional use as a demulcent for the respiratory mucosa.

4. Established and Proposed Mechanisms of Action

Antioxidant Mechanisms

Antioxidant activity is the main factor in the plant's success in clearing out reactive oxygen species (ROS), as tested in DPPH assays. In an in vitro investigation, ethanolic extract of A. capillus-veneris leaves was assessed against hydrogen peroxide-induced oxidative damage in peripheral blood lymphocytes, and the results demonstrated inhibition of lipid peroxidation and an increase in the level of antioxidant enzymes including SOD, CAT, Gpx, and glutathione content.

Anti-inflammatory Mechanisms

The anti-inflammatory relationship involves modulation of inflammatory mediators such as TNF-α, IL-6, and prostaglandin E2 through suppression of the NF-κB pathway. Ethanol extract of A. capillus-veneris and its fractions were reported to possess anti-inflammatory effects in animal models by suppressing nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) synthesis and release, as well as inhibiting NF-κB activation.

Wound Healing Mechanisms

The potential of A. capillus-veneris fractions in wound healing was evaluated through angiogenesis and fibroblast proliferation, in addition to in vitro tests for protection against damage to fibroblasts by oxygen free radicals; the aqueous fraction promoted significant angiogenesis (p < 0.05) through capillary-like tubular formations and proliferation of endothelial cells in vitro.

Antidiabetic Mechanisms

The presence of flavonoids and tannins may be responsible for the observed antidiabetic activity. Alcoholic extract of A. capillus-veneris was reported to have antidiabetic effects in a rabbit model because of its flavonoids and antioxidant content.

5. Scientific Evidence by Area of Use

Important overall characterization: The pharmacological activities of Adiantum capillus-veneris, focusing on its antioxidant, anti-inflammatory, antimicrobial, and antidiabetic potentials, are supported predominantly by in vitro and in vivo (animal) studies. Contemporary researchers have demonstrated antioxidant, antimicrobial, and anti-inflammatory effects of this plant; however, the clinical studies conducted on the effects of this plant on respiratory diseases are few, and more research is necessary. No large-scale, well-designed human randomized controlled trials have been published in the peer-reviewed literature as of available review dates.

5.1 Antioxidant Activity

In vitro assays conducted through DPPH, scavenging capacity of superoxide anion, chelating capability of ferrous ion, and reducing power tests, as well as in vivo examination using acute mice liver injury experiments, exhibited more potent antioxidant activity of the species than some synthetic antioxidants such as BHT, EDTA, and ascorbic acid. In vivo evaluation displayed significant decreases in superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels and notable increases in malondialdehyde (MDA) levels in the untreated liver injury group, with the extract providing measurable protective effects.

Evidence strength: Preclinical (in vitro and animal). No human trials. Results are preliminary.

5.2 Anti-inflammatory Activity

To explore anti-inflammatory and anti-ulcerative effects, A. capillus-veneris aqueous extract (ACAE; 150, 300, and 600 mg/kg) and hydroalcoholic extract (ACHE; 150, 300, and 600 mg/kg) were given orally to male Wistar rats 2 hours before induction of colitis by intra-rectal administration of 3% acetic acid and continued for 4 days; prednisolone (4 mg/kg) and mesalazine (100 mg/kg) were used as reference drugs. On day five, colitis indices of tissue specimens were evaluated and levels of biochemical markers including myeloperoxidase (MPO) and malondialdehyde (MDA) were determined. Based on these animal findings, it was concluded that A. capillus-veneris may have beneficial effects in IBD because of its anti-inflammatory, antioxidant, radical scavenging, and wound healing properties.

Evidence strength: Animal study (rat colitis model). No human clinical data. Findings are preliminary and hypothesis-generating.

5.3 Antimicrobial Activity

Extracts from the leaves, stems, and roots of Adiantum capillus veneris were extracted with water, methanol, ethanol, ethyl acetate, and hexane and screened for their antimicrobial activity against ten multidrug-resistant (MDR) bacterial strains and five fungal strains isolated from clinical and water samples. The alcoholic and aqueous leaf extract was found to be effective against several strains of Gram-positive and Gram-negative bacteria and also showed antifungal properties. The extracts of the leaves have shown strong antimicrobial activities.

Evidence strength: In vitro data only. Clinical relevance has not been established in human trials.

5.4 Antidiabetic and Antiobesity Activity

In animal studies evaluating antidiabetic potential, fasting blood glucose (FBG) was measured by the glucose oxidase method on day 0 (after 72 hours of streptozotocin induction), day 10, and day 21. Improvement in FBG indicated that Adiantum capillus veneris has antidiabetic potential with low side effects, providing scientific rationale for traditional antidiabetic use. A separate study referenced in the literature (Kasabri et al., 2017) assessed antiobesity and antihyperglycaemic effects of A. capillus-veneris extracts in both in vitro and in vivo evaluations.

Evidence strength: Animal models (streptozotocin-induced diabetic rats and rabbit models) and in vitro. No published human clinical trial data. Evidence is preliminary.

5.5 Wound Healing

Angiogenic effects and protective effects against oxygen free radicals from the aqueous partition of A. capillus-veneris were suggested for local application in prevention of late radiation-induced injuries after radiation therapy and for healing of external wounds similar to bedsores and burns. A more recent study evaluated the effects of methanol extracts of A. capillus-veneris (ACVM) on cell proliferation, migration, and antioxidative capacity in human keratinocytes (HaCaT), and anti-inflammatory activity in RAW 264.7 cells. A systematic review of evidence also found wound healing effects in both diabetic and non-diabetic patients and protection against damage to fibroblasts via free radicals.

Evidence strength: Primarily in vitro; some reference to wound healing "effects" in patients (cited in one systematic review of preclinical studies). Robust controlled human clinical trials are lacking.

5.6 Thyroid and Anti-goitrogenic Activity

A study was designed to investigate the potency of A. capillus-veneris on thyroid dysfunction — specifically hypothyroidism — by determining thyroid gland weight, thyroid peroxidase activity, estimation of iodine in urine, and concentrations of total thyroxine (T4), triiodothyronine (T3), and thyroid stimulating hormone (TSH) in serum. In propylthiouracil (PTU)-induced hypothyroidism, the ethanolic extract at 500 mg/kg showed significant increases in the levels of T3 and T4, a decrease in the level of thyroid stimulating hormone, and reversal of the thiouracil-induced increase in thyroid weight (goitre), suggesting a thyroid hormone–enhancing effect and anti-goitrogenic effect. However, there is a need to test lower doses of the extract for evaluating actual anti-goitrogenic potential.

Evidence strength: Animal study only (induced hypothyroid rodent model). No human data available.

5.7 Anticonvulsant and Analgesic Activity

Ethanolic A. capillus-veneris extracts produced anticonvulsant and analgesic effects in mice, verified in pentylenetetrazole, maximal electroshock, hot-plate, and tail-immersion tests. A comprehensive review of pharmacological activities also documented anticonvulsant, depressant, analgesic, and anti-nociceptive activities.

Evidence strength: Animal models only. No human clinical evidence.

5.8 Antidiarrheal and Antispasmodic Activity

Among the pharmacological effects ascribed to A. capillus-veneris, antidiarrheal and antispasmodic properties have been documented. Janbaz et al. investigated antidiarrheal and antispasmodic activities of the plant and found effects attributed predominantly to calcium channel antagonism and related mechanisms in animal models. These findings have been cited in multiple reviews but remain confined to preclinical settings.

Evidence strength: Animal models. No robust human clinical data.

5.9 Anti-urolithiatic (Kidney Stone) Activity

The hydroalcoholic extract of leaves has shown strong anti-urolithic properties, as is usually claimed in traditional medicine. In ITM, the plant was also reported as useful for dissolving kidney calculi and as a diuretic agent when administered orally.

Evidence strength: In vitro crystallization inhibition studies. No human clinical trial data available.

5.10 Respiratory Applications

The fern is used in the fight against several respiratory problems such as cough, bronchitis, and asthma, as well as for the control of fever, treatment of skin diseases, normalization of liver function, treatment of hair-related diseases (hair loss), kidney stones, allergy, and hypertension. However, there is no direct demonstrated relationship between the pharmacological activities of this plant in Iranian traditional medicine and modern phytotherapy; the anti-inflammatory and antimicrobial properties of this plant could make it useful for respiratory tract disorders, but this has not been directly confirmed in clinical trials.

Evidence strength: Traditional use is well-documented; preclinical findings are supportive but human clinical trials on respiratory outcomes are absent.

5.11 Lung Alveolar and Organ-Protective Effects

Pharmacological review findings include effects on remodeling of lung alveolar epithelial cells in a hypoxic environment and anti-toxicity properties in liver and testes. Additional documented activities include anti-toxicity properties in liver and testes, anti-hyperglycemic effects, and wound healing in diabetic and non-diabetic animal models.

Evidence strength: Preclinical only.

6. Body Systems and Health Areas of Association

Respiratory system: The ethnobotanical uses include treatment of respiratory disorders such as bronchitis, asthma, and pneumonia.
Urogenital system: According to ITM, maidenhair fern was prescribed for the treatment of respiratory and urogenital diseases, the latter being among the most important uses.
Gastrointestinal system: Oral powders of maidenhair fern were administered extensively for gastrointestinal disorders such as jaundice, diarrhea, and abdominal cramps.
Integumentary system (skin and hair): The plant has been topically used in skin and hair disorders.
Endocrine system (thyroid): Preclinical evidence for goitrogenic and anti-thyroidal effects, as documented in animal studies reviewed above.
Nervous system: Activity against testosterone-induced alopecia, anticonvulsant, depressant, analgesic, and anti-nociceptive activities have been documented in preclinical research.
Metabolic/glycemic: Anti-hyperglycemic effects demonstrated in animal models.
Immune/inflammatory: NF-κB inhibition and suppression of pro-inflammatory cytokines (TNF-α, IL-6) in preclinical studies.

7. Dosage Forms and Reported Dosages

The following dosages and preparations are reported only as stated in historical, traditional, or pre-clinical source materials. No standardized or approved human clinical dosages have been established through rigorous trials.

Traditional and Historical Preparations

Decoction: Decoction (one ounce herb to one pint water); dose of 1 to 4 fluid ounces, as recorded in early American eclectic sources.
Infusion: Infusion (one ounce herb to one pint water); dose of 1 to 4 fluid ounces.
Syrup (Sirop de capillaire): Syrup prepared from adiantum 1 part, boiling water 10 parts, and sugar 19 parts (infused, adding the sugar after straining); dose of 1 or 2 tablespoonfuls.
Leaf infusion (traditional preparation): One cup of leaf infusion twice daily, or 1–2 g of powdered leaf in tablets or capsules twice daily.
Unani medicine: Therapeutic doses in Unani medicine range from 3–7 g depending on the preparation.

Doses Used in Preclinical Research

Anti-inflammatory (colitis) study: Aqueous extract (ACAE) and hydroalcoholic extract (ACHE) at doses of 150, 300, and 600 mg/kg were administered orally to male Wistar rats 2 hours before induction of colitis and continued for 4 days.
Thyroid study: The ethanolic plant extract was administered at 500 mg/kg to experimental animals.

8. Safety Considerations

General Safety Profile

Adiantum capillus-veneris L. (Family: Pteridaceae) is described in peer-reviewed literature as a well-known safe medicinal herb used in traditional and modern medicine due to its beneficial pharmacological properties. It is recognized as a traditional medicinal plant for use in specified indications exclusively based upon long-standing use.

Goitrogenic / Thyroid Interactions

Maidenhair fern was found to possess goitrogenic and anti-thyroidal effects in modern pharmacological investigation, among its documented activities. The thyroid-modulating effects demonstrated in animal models — including alterations in serum T3, T4, and TSH levels — indicate that individuals with thyroid conditions or taking thyroid medications should be aware of this potential pharmacological interaction. This effect has been demonstrated only in animal models and not confirmed in humans.

Reproductive and Emmenagogue Properties

Traditionally, the maidenhair fern was used as a mild diuretic and often utilized to promote menstruation in women. Its traditional use as an emmenagogue (agent to stimulate menstrual flow) and to facilitate childbirth, as documented in ITM and Brazilian herbal medicine, implies caution regarding use during pregnancy, although controlled human safety data are not available in the reviewed literature.

Lack of Human Toxicology Data

A systematic review of pharmacological and toxicological effects conducted an incisive search through PubMed, Scopus, ScienceDirect, and Cochrane Library, including all related in vivo, in vitro, and human studies in English published up to January 2019. Despite this comprehensive search scope, formal human toxicology data remain sparse. The absence of large-scale human safety studies means that maximum tolerable doses, long-term safety, and potential herb-drug interactions are not established with confidence in the scientific literature.

Potential Interactions with Calcium Oxalate Crystallization

The hydroalcoholic extract of leaves has shown anti-urolithic properties by inhibiting calcium oxalate crystallization in vitro. This suggests possible interactions in individuals prone to calcium oxalate kidney stones, and while the direction of effect is potentially beneficial, it has not been evaluated in human subjects.

Caution Regarding Pan-Assay Interfering Substances (PAINS)

Although compounds such as chlorogenic acid and rutin in A. capillus-veneris exhibit well-established wound-healing, anti-inflammatory, and antioxidant properties, their classification as pan-assay interfering substances (PAINS) necessitates cautious interpretation of in vitro data. This is an important caveat for evaluating the in vitro pharmacological literature on this plant.

References

Health Conditions

Health conditions that Maidenhair fern may help support.

No conditions available.

Body Systems

Body systems that Maidenhair fern may help support.

No body systems available.