Motherwort

Motherwort (Leonurus cardiaca L.)

1. Identity and Botanical Description

Leonurus cardiaca, known as motherwort, is an herbaceous perennial plant in the mint family, Lamiaceae. Other common names include throw-wort, lion's ear, and lion's tail. In other European languages it is called Echte Herzgespann in German and agripaume in French. The genus name Leonurus derives from the Greek leon (lion) and ouros (tail), reflecting the shape of the plant's flowering spikes, while the species epithet cardiaca (of the heart) encapsulates its principal historical therapeutic association.

Originally from Central Asia and southeastern Europe, it is now found worldwide, spread largely due to its use as a herbal remedy. Leonurus cardiaca is a perennial plant indigenous to central Europe and Scandinavia, but it is also found in the area spanning temperate Russia to central Asia, and has been introduced to North America, where it has become established locally in the wild.

Leonurus cardiaca has a squarish stem which is clad in short hairs and is often purplish, especially near the nodes. The opposite leaves have serrated margins and are palmately lobed with long petioles; basal leaves are wedge shaped with three points while the upper leaves have three to five. They are slightly hairy above and greyish beneath. Flowers, grouped in 10–20 clusters in the leaf axils of the last 10–15 knots, are pink and about 1 cm long. The plants grow up to 1 m, with the hollow aerial stalks growing from the rhizomes.

Within the genus Leonurus, L. japonicus (also recorded as L. heterophyllus) and L. cardiaca are the typical species used in Eastern Asia and Europe, respectively. Other species investigated in research include L. persicus (Turkey, Iran), L. sibiricus (Mongolia, Siberia), L. macranthus (Northeast Asia), L. turkestanicus (Central and West Asia), and L. glaucescens (Northwest Asia). These species share some constituents and pharmacological properties but differ in their chemical profiles, a distinction that is clinically and analytically important.

2. Common Forms and Preparations

Motherwort (Leonuri cardiacae herba) consists of aerial parts of Leonurus cardiaca gathered during the flowering period, dried at 35°C and, according to European Pharmacopoeia 7th edition, should contain a minimum of 0.2% flavonoids, expressed as hyperoside. The HMPC conclusions of the EMA cover motherwort preparations obtained by drying and either comminuting or powdering the flowering parts, or by extracting the plant material in a solvent such as ethanol to form a liquid extract. Herbal medicines containing these preparations are usually available as herbal tea to be drunk or in liquid and solid forms taken by mouth.

Available dosage forms include:

• Infusion (tea): prepared by pouring 150 mL of boiling water over 2 to 4 g of motherwort and straining after 10 minutes.
• Tinctures (liquid alcoholic extracts), standardized dry extracts in capsule or tablet form.
• Capsules, which will usually contain between 200 and 500 mg of dried herb.
• Besides traditional medical use, motherwort is also used in some cuisines as a condiment in vegetable soup recipes, or for flavoring beer and tea.

3. Traditional and Historical Use

3.1 European Traditions

Charles Pickering, a late 19th-century American naturalist and doctor, indicates that motherwort likely originated in central and northern Asia (Japan and Siberia) and spread westward to Western Europe, where its use becomes better documented beginning at the start of the 17th century. Historically utilized by ancient Greeks and Romans for heart palpitations and emotional distress, motherwort was also employed in European herbal practices to stimulate the uterus, aid in menstrual regulation, and support labor.

In 1598, uses of motherwort were documented in The Herball or Generall History of Plants written by John Gerard, an English botanist and herbalist. This book, often referred to as "Gerard's Herbal," was widely circulated in England in the 17th century and was relied upon by American colonists. Nicholas Culpeper considered motherwort useful for removing melancholy vapors from the heart, improving cheerfulness, and settling the wombs of mothers. In 15th-century Europe, motherwort was considered by some herbalists to protect against evil spirits.

Traditionally, extracts of the herb have been used internally, mainly for nervous heart conditions and digestive disorders, but they have also been used for bronchial asthma, climacteric symptoms, and amenorrhea, as well as externally for wounds and skin inflammations.

3.2 Traditional Chinese Medicine

In traditional Chinese medicine, motherwort is known as "Yi Mu Cao," which translates to "beneficial mother herb," and is used to promote menstrual health and alleviate symptoms associated with childbirth. These uses correspond with those in traditional Chinese medicine, which employs the Asian variety to treat menstrual disorders or to help a woman expel a dead fetus and placenta. In eastern China, women still drink a syrup made from motherwort to promote recovery of the uterus after childbirth; the herb has a strong bitter taste, so visitors to a recovering mother often bring along sugar as a gift.

3.3 Obstetrical and Gynecological Uses

Leonurus is a traditional childbirth and postpartum botanical that has been used for centuries as a galactogogue and uterine tonic both before and after childbirth. Having emmenagogue actions, presumably because of both hormonal and vascular effects, it has been used to treat various gynecologic and obstetrical conditions including amenorrhea, fertility, menstrual discomforts, and thyroid disorders.

The plant was historically used as a cardiotonic and for treating gynaecological afflictions such as amenorrhea, dysmenorrhea, menopausal anxiety, and postpartum depression.

3.4 Other Traditional Uses

Folkloric uses of motherwort emphasized its use as a calming and relaxing herbal agent with tonic effects on hormonal, nervous, and cardiac systems. In Eastern European folk remedies, motherwort has been traditionally used to calm the nerves and treat various gynecological disorders.

4. Key Constituents and Active Compounds

Compounds belonging to the group of monoterpenes, diterpenes, triterpenes, nitrogen-containing compounds, phenylpropanoids, flavonoids and phenolic acids, as well as volatile oils, sterols, and tannins, have been identified in motherwort. More than 280 secondary metabolites have been isolated from Leonurus, including alkaloids, terpenes, flavonoids, phenylpropanoids, polysaccharides, and volatile oils.

4.1 Alkaloids

Leonurine is the most discussed alkaloid associated with the genus Leonurus. It is a prominent pharmacologically active guanidine alkaloid (4-{[amino(imino)methyl]amino}butyl-4-hydroxy-3,5-dimethoxybenzoate), mainly exerting cardiovascular, hypotensive, uterotonic, and neuroprotective effects. However, its presence in L. cardiaca specifically is disputed. No leonurine could be detected in any sample of L. cardiaca in contrast to some newly published official drug assessments, which consequently have to be revised. In aerial parts of L. japonicus drug samples obtained from China and Japan, leonurine contents between 0.001 and 0.049% were determined, while L. japonicus from domestic cultivation displayed significantly higher amounts of at least 0.1%. This finding underscores the importance of species-level differentiation in interpreting pharmacological claims attributed to leonurine.

Stachydrine ((2S)-1,1-dimethylpyrrolidinium-2-carboxylic acid) is confirmed in L. cardiaca. HPTLC measurements of 12 drug samples revealed stachydrine contents of 0.6 to 1.5% for L. cardiaca aerial parts and 6.7% for an antiarrhythmic refined extract of L. cardiaca. As a major clinical application in folk medicine, the uterotonic activity of motherwort is owed in part to the alkaloid stachydrine.

In addition to leonurine and stachydrine, Leonurus cardiaca contains iridoid glycosides such as leonuride and the alkaloids leonurinine.

4.2 Flavonoids

Among other chemical constituents, motherwort contains bitter iridoid glycosides (leonuride), diterpenoids, flavonoids (including rutin and quercetin), tannins, volatile oils, and vitamin A. Among specifically identified flavonoids, catechin, hyperoside, and rutin are present in the extracts. Quality Leonurus products should contain at least 0.2% flavonoids, often standardized to hyperoside content.

4.3 Phenolic Acids and Other Polyphenols

Among hydroxycinnamic acids identified in motherwort extracts, chlorogenic, caffeic, and rosmarinic acids have been confirmed, with chlorogenic and caffeic acids being the dominant ones. The extracts also have a significant content of ellagic acid.

4.4 Diterpenes

A systematic review of the genus identified 259 compounds isolated from Leonurus, featuring 147 labdane diterpenoids. The phenylpropanoid glycoside lavandulifolioside is a notable constituent. The pharmacological properties of lavandulifolioside include significant negative chronotropism, prolongation of the P–Q, Q–T intervals and QRS complex, and decrease in blood pressure.

5. Mechanisms of Action

5.1 Cardiovascular Mechanisms

Cardiovascular diseases often involve an alteration of cardiac muscle mitochondria, and agents that support mitochondrial function show promise in preserving heart function. Leonurus constituents chlorogenic acid, orientin, quercetin, hyperoside, and rutin are all credited with antioxidant activity and are shown to attenuate the production of reactive oxygen species in the mitochondria, a proposed mechanism of cardioprotection.

Stachydrine was proven to ameliorate homocysteine-induced endothelial dysfunction via nuclear factor erythroid 2–related factor 2 (Nrf2) dependent upregulation of guanosine triphosphate cyclohydrolase I (GTPCH1) and dihydrofolate reductase (DHFR) enzymes, increasing bioavailabilities of tetrahydrobiopterin (BH4) and nitric oxide (NO), thus protecting endothelial function.

Lavandulifolioside demonstrates significant negative chronotropism, prolongation of the P–Q, Q–T intervals and QRS complex, and decrease of blood pressure in animal models. In vitro, motherwort extracts reduced coronary output in a rat heart model and reduced platelet aggregation and platelet-activating factor (PAF) secretion.

Research in rats suggests that stachydrine can inhibit the NF-κB signal pathway, which may be related to its mechanism of anti-hypertrophic action on myocardial cells.

5.2 Sedative and Anxiolytic Mechanisms

In vivo experiments with motherwort extracts showed sedative and analgesic properties. Results from pharmacological studies indicate the presence of anxiolytic activity in motherwort extracts studied in complex with amino acids, with extracts modified with glycine, valine, and arginine being more effective in reducing anxiety in animals.

5.3 Uterotonic Mechanisms

The uterotonic activity of motherwort in folk use is attributed to the alkaloids leonurine and stachydrine. Alkaloids from Leonurus also possess other pharmacological effects, with highlighted cardiovascular protection of leonurine.

5.4 Antinociceptive (Analgesic) Mechanisms

In a controlled animal study, acute treatment of mice with an ethanolic extract at doses of 500 and 250 mg/kg by intraperitoneal administration produced significant antinociceptive effects in the formalin test, and the hot plate and tail flick tests showed an increase in antinociceptive effect at 500 mg/kg, suggesting that Leonurus cardiaca possesses both central and peripheral antinociceptive actions.

5.5 Antioxidant and Anti-Inflammatory Mechanisms

In vitro experiments with motherwort and its extracts demonstrated antioxidant, radical scavenging, antimicrobial, and anti-adhesive effects. Motherwort (Leonurus cardiaca) possesses antibacterial, antioxidant, anti-inflammatory, and analgesic activities.

5.6 Broader Pharmacological Activities

In addition to the traditional uterine contraction and sedative activity, recently the cardiovascular protection effect of leonurine has drawn the most attention. Other reported activities from various Leonurus compounds include neuroprotection, anti-inflammation, anti-cancer effects, and anti-platelet aggregation.

6. Scientific Evidence by Area of Use

6.1 Cardiovascular Health: Hypertension, Heart Rate, and Palpitations

This is the area with the most human clinical evidence for motherwort, though it remains limited in quantity and scope.

The most cited human trial is the open-label study by Shikov et al. (2011). The study was carried out to assess the clinical efficacy of Leonurus oil extract (LOE) in patients with arterial hypertension stages 1 and 2, accompanied by anxiety and sleep disorders. Fifty patients were treated for 28 days with 1200 mg LOE per day. Positive effects of LOE on psycho-emotional status and arterial blood pressure in patients with stage 1 hypertension were observed one week earlier than in patients with stage 2 hypertension. According to the Clinical Global Impression (CGI) scale, a significant improvement in the symptoms of anxiety and depression was observed in 32% of patients, a moderate improvement in 48%, and a weak effect in 8%; 12% of patients did not respond to therapy.

The clinical trial conducted by Shikov et al. on fifty patients treated with 1200 mg L. cardiaca oil extract per day for 28 days revealed significant changes in systolic blood pressure, diastolic blood pressure, heart rate, and ECG for patients with stages 1 and 2 arterial hypertension, accompanied by an improvement of psychoemotional status including anxiety, emotional lability, headache, and sleep disorders, especially visible for stage 1 patients.

In a separate open clinical trial, patients with stage 1 arterial hypertension, accompanied by anxiety and sleep disorders, improved significantly after treatment with motherwort. Both trials are open-label and without placebo controls, which constitutes a major limitation. Regarding hyperthyroidism-related symptoms, motherwort is traditionally known as a heart tonic and uterine stimulant; in vitro, the plant has demonstrated negative chronotropic effects, but there are no complete controlled studies in humans for motherwort specifically in this indication.

Leonurus cardiaca has been credited with antioxidant and anti-inflammatory activity and an ability to improve heart function and blood circulation, partly via mild negative chronotropic effects and hypotensive activity, as demonstrated in clinical trials.

Evidence strength: While some evidence suggests that motherwort may help manage irregular heart rhythms, anxiety, and certain menstrual issues, many claims lack robust scientific validation. The existing human cardiovascular evidence is preliminary and derives from small, open-label, uncontrolled trials. No large, double-blind, placebo-controlled randomized controlled trials (RCTs) have been published.

6.2 Anxiety and Nervous Tension

The EMA's HMPC concluded that, on the basis of its long-standing use, motherwort preparations can be used to relieve symptoms of nervous tension and nervous conditions of the heart such as palpitations (more noticeable heartbeats), after serious conditions have been excluded by a medical doctor. This designation is based on "traditional use" rather than demonstrated clinical efficacy from RCTs.

Results from animal pharmacological studies indicate the presence of anxiolytic activity in motherwort extracts, with extracts combined with glycine, valine, and arginine being more effective in reducing anxiety in animals. These are preclinical results only and cannot be directly extrapolated to human use without confirmatory clinical trials.

Evidence strength: Regulatory recognition exists at the traditional use level in Europe. Animal data support anxiolytic potential. Human-specific RCT evidence is absent as of the most current available data.

6.3 Postpartum Hemorrhage (Asian Species)

One human randomized controlled trial showed an Asian species of motherwort, Leonurus heterophyllus, to prevent postpartum hemorrhage after cesarean section when used in a parenteral form. Research from 2019 suggests that treatment with motherwort and oxytocin may reduce the risk of postpartum blood loss compared with oxytocin alone. These findings primarily concern Asian Leonurus species used in injection form, not oral preparations of L. cardiaca typically available in the West.

Evidence strength: RCT data exists for parenteral Asian species preparations for postpartum hemorrhage; extrapolation to oral L. cardiaca supplements is not established.

6.4 Thyroid Hyperfunction (Adjuvant Use)

Motherwort appears to reduce secondary symptoms of hyperthyroidism (heart palpitations and tachycardia). It is approved by the German Commission E for nervous cardiac disorders and as an adjuvant for thyroid hyperfunction. The German Commission E states that motherwort can be used for irregularities related to the heart caused by overstimulation of the thyroid gland (hyperthyroidism/thyrotoxicosis). This approval relates specifically to symptomatic management of cardiac manifestations (tachycardia, palpitations) rather than to any direct effect on thyroid hormone levels.

Evidence strength: Commission E approval exists for adjuvant symptomatic use in hyperthyroid cardiac complaints. This is not supported by large-scale RCTs and represents expert consensus based on long-standing traditional use and preclinical evidence of negative chronotropic activity.

6.5 Analgesic Effects

A controlled animal study investigated the effect of an alcoholic extract of the aerial part of Leonurus cardiaca on nociceptive response using formalin, tail flick, and hot plate tests in mice. Acute treatment with an ethanolic extract at doses of 500 and 250 mg/kg by intraperitoneal administration produced significant antinociceptive effects in both phases of the formalin test. The hot plate and tail flick tests showed an increase in antinociceptive effect at 500 mg/kg. These results suggest that Leonurus cardiaca possesses central and peripheral antinociceptive actions.

Evidence strength: Preclinical (animal) only. No human clinical data are available for analgesic applications.

6.6 Cardioprotection and Mitochondrial Function

Motherwort is used as a complementary remedy to improve heart function and blood circulation. Since cardiovascular diseases are often associated with an alteration of mitochondria — the main producers of ATP in cardiac muscle cells — research has investigated bioactive constituents present in motherwort aerial part extracts and their effects on the functions of cardiac mitochondria. These investigations are largely in vitro or in preclinical animal models.

Evidence strength: Mechanistic in vitro and animal data support the hypothesis of cardioprotection via antioxidant and mitochondrial mechanisms. No human RCTs exist specifically designed to test cardiac mitochondrial endpoints.

7. Body Systems Associated with Motherwort

• Cardiovascular system: The therapeutic indication recognized by ESCOP is mild cardiac complaints of nervous origin. Effects include mild negative chronotropism (slowing of heart rate) and mild hypotensive action.
• Central nervous system / nervous system: Sedative, anxiolytic, and nervine properties are recognized in preclinical and traditional use contexts.
• Reproductive and gynecological system: The uterotonic activity of motherwort in folk medicine is attributed to its alkaloid content. Emmenagogue, uterine tonic, postpartum recovery, and management of menstrual irregularities are all traditional indications.
• Thyroid: Symptomatic adjuvant use for cardiac manifestations of hyperthyroidism is Commission E approved.
• Digestive system: Traditionally, extracts of the herb have been used internally, mainly for nervous heart conditions and digestive disorders.
• Immune and inflammatory: Antioxidant, anti-inflammatory, and antimicrobial activities have been demonstrated in vitro.

8. Dosage Forms and Dosages Reported in Sources

The following dosages are reported in official monographs, pharmacopeial sources, or cited clinical studies. They are presented as documented in those sources and are not recommendations.

• Germany's Commission E recommends a dose of 4.5 grams of dried herb daily, or the equivalent, for the treatment of irregular or rapid heartbeat and hyperthyroidism.
• The daily dose referenced in pharmacopeial commentary is 3 to 10 g of the drug; for tea preparation, 150 mL of boiling water is poured over 2 to 4 g of motherwort and strained after 10 minutes. Tea may be taken three times a day.
• In the Shikov et al. clinical trial, fifty patients were treated for 28 days with 1200 mg of Leonurus oil extract (LOE) per day.
• Leonurus capsules will usually contain between 200 and 500 mg of dried herb.
• Motherwort medicines should only be used in adults, per EMA guidance.
• The use of motherwort in children and adolescents under the age of 18 is not recommended due to a lack of evidence.

9. Safety Considerations and Drug Interactions

9.1 Pregnancy and Lactation

Motherwort medicines must not be taken during pregnancy. Leonurus has traditional use as an emmenagogue — a botanical known to promote menstrual flow — and should be avoided by pregnant women in the first trimester, especially in those with a history of miscarriage. No safety studies are available on the use of motherwort during lactation.

9.2 General Toxicological Profile

Preclinical safety data assessed in acute toxicity and mutagenicity studies showed low toxicity and no mutagenic activity, respectively. Safety data assessed in a human study showed adverse effects were minimal in all treatment groups.

9.3 Anticoagulant and Platelet Effects

In vitro, motherwort reduced platelet aggregation and PAF secretion. This antiplatelet activity implies a potential interaction with anticoagulant or antiplatelet medications. Caution is warranted in individuals taking blood-thinning drugs or who have coagulation disorders, given the documented in vitro effect on platelet aggregation, though human pharmacokinetic and drug interaction studies have not been published for this specific combination.

9.4 Sedative Interactions

Motherwort has documented sedative properties in animal models. Medscape monograph data indicates motherwort contains chemicals that have vasorelaxing and cardiotonic effects described as "digoxin-like," as well as emmenagogue properties. Due to its sedative profile, pharmacodynamic synergism with central nervous system depressants — including sedative medications and other sedative herbal preparations — is a recognized concern.

9.5 Cardiac Glycoside Interactions

The digoxin-like activity attributed to some motherwort constituents (particularly lavandulifolioside's effects on cardiac conduction intervals as documented in animal models) means that caution is warranted in patients taking cardiac glycoside drugs such as digoxin, although human pharmacokinetic interaction data are not available.

9.6 Thyroid Medication Interactions

Motherwort is approved by the German Commission E as an adjuvant for thyroid hyperfunction symptoms. Simultaneous use alongside thyroid-modulating drugs should be monitored, given potential additive or unpredictable cardiovascular effects, though no formal interaction studies have been published.

9.7 Regulatory Status and Monograph Coverage

The EMA's HMPC concluded that, on the basis of its long-standing use, motherwort preparations can be used to relieve symptoms of nervous tension and nervous conditions of the heart such as palpitations, after serious conditions have been excluded by a medical doctor. The ESCOP herbal monograph selects and summarizes scientific studies and textbooks regarding efficacy, dosage, and safety to support the therapeutic uses of motherwort, covering the flowering aerial parts of Leonurus cardiaca L. and its main characteristic constituents: flavonoid glycosides, diterpenes, phenylpropanoids, alkaloids, and the volatile oil.

Evidence is mixed: modern clinical research is limited and small, but European regulators recognize motherwort for specific traditional use indications.

10. Notes on Inter-Species Confusion and Quality

Leonurine is frequently described as the predominant active principle of the genus Leonurus, yet analytical HPLC studies found no leonurine detectable in any sample of L. cardiaca, in contrast to some published official drug assessments which consequently require revision. Leonurine is, however, confirmed in L. japonicus from China and Japan, in quantities ranging from 0.001% to over 0.1% depending on cultivation. Many published pharmacological studies on leonurine's cardiovascular and uterotonic properties were conducted using L. japonicus or isolated leonurine, and their findings should not be uncritically attributed to oral L. cardiaca supplements unless species and constituent content are verified.

Leonurine has been reported to be a constituent of Leonurus cardiaca; however, some assays could not confirm its presence in L. cardiaca. This ambiguity in the literature makes it essential for quality-conscious manufacturers and researchers to verify species identity and constituent profiles through validated analytical methods such as HPLC.

References

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