Plant Comparison
Motherwort vs Japanese knotweed
A side-by-side comparison of two medicinal plants — every documented constituent, action, use, safety note and cited source, assembled automatically from the Omnia Sana database.
At a glance
Motherwort and Japanese knotweed: they share 4 indicated uses (arthritis / joint pain, cardiovascular / heart health, inflammation (general), …); 2 pharmacological actions in common.
Evidence face-off — shared uses
| Condition | Motherwort | Japanese knotweed | Verdict |
|---|---|---|---|
| Arthritis / joint pain | 1/10 | 2/10 | Comparable evidence |
| Cardiovascular / heart health | 2/10 | 1/10 | Comparable evidence |
| Inflammation (general) | 1/10 | 7/10 | Stronger for Japanese knotweed |
| Skin irritation | 1/10 | 1/10 | Comparable evidence |
Evidence scores (1–10) are computed from the tier of each cited source. “Comparable” means the two scores are within one point. Follow a score to its detailed sources.
Key Constituents
Leonurine and related iridoid/alkaloid-type constituents are considered the principal cardioactive and uterotonic compounds.
Antioxidant constituents contributing to the plant's anti-inflammatory activity.
Bitter diterpenes, shared with related Lamiaceae bitters, contributing to the traditional digestive and cardiac reputation.
Considered the principal bioactive constituents, responsible for much of the antioxidant, anti-inflammatory and cardioprotective activity attributed to this root.
Emodin has laxative and anti-inflammatory activity at typical concentrations but can cause gastrointestinal upset at high doses.
Pharmacological Actions
Traditional & Indicated Uses
inferred from anti-inflammatory action
inferred from anti-inflammatory action
inferred from sedative action
inferred from antispasmodic action
inferred from anti-inflammatory action
inferred from anticancer action
inferred from anti-inflammatory action
Safety, Cautions & Contraindications
Contraindicated in pregnancy (uterine stimulant). Avoid in heavy menstrual bleeding. May enhance anticoagulant and antihypertensive drug effects. Avoid in thyroid disorders. Generally well tolerated in normal doses for short-term use.
Duke (2002) rates motherwort as ++ and notes hypotensive, cardiotonic (negative chronotropic), anti-aggregant, and sedative activities at the experimental level (score 1). The plant is traditionally used for heart palpitations, hypertension, and menstrual regulation in European herbalism. Duke emphasizes strong safety caution: motherwort has documented oxytocic (uterine-stimulating) activity and is strictly contraindicated in pregnancy. It may also enhance the effects of cardiac medications and sedatives (Duke, 2002).
Japanese knotweed root contains resveratrol and emodin; high doses of emodin may cause GI discomfort and have laxative effects. Not recommended during pregnancy (emodin has potential teratogenic effects in animal studies). May interact with anticoagulants and antiplatelet medications. Quality control of commercial preparations is important as invasive weed extracts vary significantly.
Duke (2002) rates Japanese knotweed (listed as Hu-Zhang, Fallopia japonica) as +++ and highlights its rich content of resveratrol and emodin. Experimental evidence (score 1) supports COX-2 inhibitory, antioxidant, anti-inflammatory, hepatoprotective, and lipid-lowering activities — largely attributed to resveratrol. Duke notes its use in traditional Chinese medicine for fractures, burns, abscesses, and gynecological conditions. No significant clinical trials were available at time of publication, but resveratrol's biological activity is well-documented in vitro (Duke, 2002).
External Ids
Botanical Description
Tall, upright perennial herb with deeply palmately lobed lower leaves (giving a lion's-paw appearance, the source of the genus name) and progressively less-divided upper leaves. Small, pink to pale purple, spiny-toothed, two-lipped flowers are borne in dense whorls up the square stem.[1]
Vigorous, invasive rhizomatous perennial (Polygonaceae) with hollow, bamboo-like, jointed stems 1-3 m tall (occasionally taller), speckled reddish-purple. Leaves are broad, heart- to shovel-shaped with a flat base. Abundant sprays of small, creamy-white flowers appear in late summer, followed by small winged fruit.[6]
Habitat
Grows on waste ground, roadsides, hedgerows and near old dwellings; native to Central Asia and southeastern Europe and long naturalised across Europe and North America.[1]
Native to East Asia (Japan, China, Korea), now a notorious invasive species across Europe and North America, growing in disturbed ground, riverbanks, roadsides and waste land, spreading aggressively via an extensive rhizome network.[6]
Harvesting
The flowering aerial parts (leaf, stem and flower) are cut in summer as the plant comes into flower, and dried in a warm, shaded, airy place.[1]
The rhizome/root, the main medicinal part, is dug in autumn or winter when resveratrol content is highest; young spring shoots (stems) are also edible and used. Strict containment is required when harvesting, given the plant's severe invasiveness.[6]
Traditional Uses
Motherwort has a long European and Asian herbal tradition, reflected in its name, as a gynaecological and cardiac tonic, traditionally used for heart palpitations and nervous cardiac complaints, menstrual irregularities and cramps, and as a calming nervine for anxiety and to ease childbirth and postpartum recovery.[1, 6]
Known as Hu Zhang in Traditional Chinese Medicine, Japanese knotweed root has a centuries-old use for inflammation, infections, jaundice and menstrual complaints. Modern interest centres on its resveratrol and emodin content, now studied (as Polygonum cuspidatum extract) for antioxidant, anti-inflammatory, cardioprotective and hepatoprotective activity, and more recently for supportive use in acute respiratory infections.[2, 3, 6]
Preparations
Dosage
The EU herbal monograph gives a single dose of 1.5-4.5 g of the comminuted herb for tea preparation, for a daily dose of 3-10 g, in adults and elderly; a 1:5 tincture in 45% V/V ethanol at 2-6 mL three times daily and a liquid extract at 2-4 mL three times daily are also listed. If symptoms persist longer than 4 weeks a healthcare practitioner should be consulted. Not recommended under 18 years. Educational reference only, not a prescription.
Duke (2002) and general phytotherapy guidance treat this as an experimentally supported herb without a single agreed clinical dose; commercial resveratrol-standardised extracts should be dosed per product labelling. Educational reference only, not a prescription; avoid in pregnancy.
References
Drug Class Interactions
Not documented
Lookalikes Review
References & Sources
- Fierascu, R.C., Fierascu, I., Ortan, A., Fierascu, I.C. and others (2019) 'Leonurus cardiaca L. as a Source of Bioactive Compounds: An Update of the European Medicines Agency Assessment Report (2010)', BioMed Research International, 2019, pp. 4303215. doi:10.1155/2019/4303215 Traditional / reference
https://doi.org/10.1155/2019/4303215 - Wojtyniak, K., Szymanski, M. and Matlawska, I (2013) 'Leonurus cardiaca L. (motherwort): a review of its phytochemistry and pharmacology', Phytotherapy Research, 27(8), pp. 1115-1120. doi:10.1002/ptr.4850 Traditional / reference
https://doi.org/10.1002/ptr.4850 - Kuchta, K., Volk, R.B. and Rauwald, H.W (2013) 'Stachydrine in Leonurus cardiaca, Leonurus japonicus, Leonotis leonurus: detection and quantification by instrumental HPTLC and 1H-qNMR analyses', Pharmazie, 68(7), pp. 534-540. Available at: https://pubmed.ncbi.nlm.nih.gov/23923634/ Preclinical
https://pubmed.ncbi.nlm.nih.gov/23923634/ - Kuchta, K., Volk, R.B. and Rauwald, H.W (2012) 'Leonurus japonicus, Leonurus cardiaca, Leonotis leonurus: a novel HPLC study on the occurrence and content of the pharmacologically active guanidino derivative leonurine', Pharmazie, 67(12), pp. 973-979. Available at: https://pubmed.ncbi.nlm.nih.gov/23346757/ Preclinical
https://pubmed.ncbi.nlm.nih.gov/23346757/ - Koshovyi, O., Raal, A., Kireyev, I., Tryshchuk, N. and others (2021) 'Phytochemical and Psychotropic Research of Motherwort (Leonurus cardiaca L.) Modified Dry Extracts', Plants (Basel), 10(2), pp. 230. doi:10.3390/plants10020230 Preclinical
https://doi.org/10.3390/plants10020230 - Angeloni, S., Spinozzi, E., Maggi, F., Sagratini, G. and others (2021) 'Phytochemical Profile and Biological Activities of Crude and Purified Leonurus cardiaca Extracts', Plants (Basel), 10(2), pp. 195. doi:10.3390/plants10020195 Preclinical
https://doi.org/10.3390/plants10020195 - Sadowska, B., Wieckowska-Szakiel, M., Paszkiewicz, M. and Rozalska, B (2019) 'Molecular Mechanisms of Leonurus cardiaca L. Extract Activity in Prevention of Staphylococcal Endocarditis - Study on in Vitro and ex Vivo Models', Molecules, 24(18), pp. 3318. doi:10.3390/molecules24183318 Preclinical
https://doi.org/10.3390/molecules24183318 - Kuchta, K., Hladikova, J., Thomsen, M., Nguyen, A.D. and others (2025) 'Phenolic and Iridoid Glycosides from Leonurus cardiaca L. and Their Effects on the alpha, delta, and gamma Subtypes of the PPAR System', Molecules, 30(2), pp. 419. doi:10.3390/molecules30020419 Preclinical
https://doi.org/10.3390/molecules30020419 - Pereira, O.R., Catarino, M.D., Afonso, A.F., Silva, A.M.S. and Cardoso, S.M (2019) 'Hepatoprotection of Leonurus cardiaca L., Leonurus japonicus Houtt. and Leonurus sibiricus L', Antioxidants (Basel), 8(8), pp. 267. doi:10.3390/antiox8080267 Preclinical
https://doi.org/10.3390/antiox8080267 - Kuchta, K., Ortwein, J. and Rauwald, H.W (2014) '1H-qNMR for direct quantification of stachydrine in Leonurus japonicus and L. cardiaca', Fitoterapia, 96, pp. 8-17. doi:10.1016/j.fitote.2014.03.023 Preclinical
https://doi.org/10.1016/j.fitote.2014.03.023 - European Medicines Agency (HMPC) (2010) 'Community herbal monograph on Leonurus cardiaca L., herba'. Available at: https://www.ema.europa.eu/en/documents/herbal-monograph/final-community-herbal-monograph-leonurus-cardiaca-l-herba_en.pdf Traditional / reference
https://www.ema.europa.eu/en/documents/herbal-monograph/final-community-herbal-monograph-leonurus-cardiaca-l-herba_en.pdf - Kowalchik, C. and Hylton, W (1998) 'Rodale'. Traditional / reference
https://scholar.google.com/scholar?q=Rodale - Prajapati, N.D., Purohit, S.S., Sharma, A.K. and Kumar, T (2003) 'A Handbook of Medicinal Plants'. Traditional / reference
https://scholar.google.com/scholar?q=A%20Handbook%20of%20Medicinal%20Plants - Shang, X. et al (2014) 'The genus Leonurus: traditional uses, phytochemistry and pharmacology', pp. 43--63. Traditional / reference
https://scholar.google.com/scholar?q=The%20genus%20Leonurus%3A%20traditional%20uses%2C%20phytochemistry%20and%20pharmacology - Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition - Ghasemzadeh Rahbardar, M. and Hosseinzadeh, H (2024) 'Therapeutic potential of hypnotic herbal medicines: A comprehensive review', Phytotherapy Research, 38(6), pp. 3037-3059. doi:10.1002/ptr.8201 Meta-analysis / review
https://doi.org/10.1002/ptr.8201 - Block, K.I., Gyllenhaal, C. and Mead, M.N (2004) 'Safety and efficacy of herbal sedatives in cancer care', Integrative Cancer Therapies, 3(2), pp. 128-148. doi:10.1177/1534735404265003 Meta-analysis / review
https://doi.org/10.1177/1534735404265003
- Dong, X., Fu, J., Yin, X., Cao, S. and others (2016) 'Emodin: A Review of its Pharmacology, Toxicity and Pharmacokinetics', Phytotherapy Research, 30(8), pp. 1207-1218. doi:10.1002/ptr.5631 Traditional / reference
https://doi.org/10.1002/ptr.5631 - Wang, S., Yang, Y., Sun, L., Qiao, G. and others (2022) 'Reynoutria japonica Houtt for Acute Respiratory Tract Infections in Adults and Children: A Systematic Review', Frontiers in Pharmacology, 13, pp. 787032. doi:10.3389/fphar.2022.787032 Meta-analysis / review
https://doi.org/10.3389/fphar.2022.787032 - Ke, Y., Zhan, L., Lu, T., Zhou, C. and others (2023) 'Advances for pharmacological activities of Polygonum cuspidatum (Reynoutria japonica) - A review', Pharmaceutical Biology, 61(1), pp. 177-188. doi:10.1080/13880209.2022.2158349 Traditional / reference
https://doi.org/10.1080/13880209.2022.2158349 - Zhang, Q., Zhao, Y., Zhang, M., Zhang, Y. and others (2021) 'Bioactive amides from Reynoutria japonica', Journal of Asian Natural Products Research, 23(3), pp. 228-234. doi:10.1080/10286020.2021.1873298 Preclinical
https://doi.org/10.1080/10286020.2021.1873298 - Lai, Y., Zhou, C., Huang, P., Dong, Z. and others (2024) 'Polygonum cuspidatum polysaccharide: A review of its extraction and purification, structure analysis, and biological activity', Journal of Ethnopharmacology, 331, pp. 118079. doi:10.1016/j.jep.2024.118079 Traditional / reference
https://doi.org/10.1016/j.jep.2024.118079 - Peng, W., Qin, R., Li, X. and Zhou, H (2013) 'Botany, phytochemistry, pharmacology, and potential application of Polygonum cuspidatum Sieb. et Zucc.: a review', Journal of Ethnopharmacology, 148(3), pp. 729-745. doi:10.1016/j.jep.2013.05.007 Traditional / reference
https://doi.org/10.1016/j.jep.2013.05.007 - Wang, X., Liang, L., Yan, J., Li, Z. and others (2023) 'Citri Reticulatae Pericarpium-Reynoutria japonica Houtt. herb pair suppresses breast cancer liver metastasis by targeting ECM1-mediated cholesterol biosynthesis pathway', Phytomedicine, 116, pp. 154896. doi:10.1016/j.phymed.2023.154896 Preclinical
https://doi.org/10.1016/j.phymed.2023.154896 - Jiang, Y., Liu, Y., Zhang, X. and others (2020) 'New phenolic glycosides from Reynoutria japonica', Journal of Asian Natural Products Research, 22(1), pp. 17-23. doi:10.1080/10286020.2019.1646730 Preclinical
https://doi.org/10.1080/10286020.2019.1646730 - Liu, Y., Wang, J., Li, Q. and others (2024) 'The Possibility of Polygonum cuspidatum against Osteoarthritis based on Network Pharmacology', Current Computer-Aided Drug Design, 20(2), pp. 121-133. doi:10.2174/1573409919666230403114131 Preclinical
https://doi.org/10.2174/1573409919666230403114131 - Espinosa-Andrews, H., Morales-Hernandez, N., Garcia-Marquez, E. and others (2025) 'Physicochemical and rheological characteristics of commercial Greek-style yogurt enriched with Polygonum cuspidatum roots or the P. cuspidatum beta-cyclodextrin inclusion complex', Food Research International, 203, pp. 115854. doi:10.1016/j.foodres.2025.115854 Preclinical
https://doi.org/10.1016/j.foodres.2025.115854 - Burns, J., Yokota, T., Ashihara, H., Lean, M.E.J. and Crozier, A (2002) 'Plant foods and herbal sources of resveratrol', 50(11), pp. 3337--3340. doi:10.1021/jf0112973 Traditional / reference
https://doi.org/10.1021/jf0112973 - Royal Botanic Gardens, Kew (n.d.). Available at: https://powo.science.kew.org Traditional / reference
https://powo.science.kew.org - World Health Organization (2007) 'WHO Monographs on Selected Medicinal Plants'. Traditional / reference
https://scholar.google.com/scholar?q=WHO%20Monographs%20on%20Selected%20Medicinal%20Plants - Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition
Generated automatically from the Omnia Sana plant database and its cited sources. For educational purposes only — not medical advice. Always consult a qualified practitioner before using medicinal plants.