🌸🌱 Motherwort (Leonurus cardiaca) is a native perennial of Europe. It can be found growing in gardens, verges, woodland margins and disturbed land with well-drained soil and part-shade. Being a member of the mint family, Lamiaceae, it has the classic botanical features of a square stem and opposite leaf structure; the leaves have three to five points, palmately lobed with serrated margins. Tubular pink-lilac flowers, grow from fuzzy leaf axils which form whorls around the stem. At Leaf Retreat, motherwort grows happily amongst the climbing vegetables growing up to 1.5 metres tall, attracting a variety of pollinators with its sweet nectar. Interestingly, the irregular flowers, with their bilateral symmetry are thought to have evolved to ensure the efficient transfer of pollen.

🌸🌱 The common name alludes to its traditional use as a heart tonic and for treating gynaecological afflictions, such as painful periods (dysmenorrhea), absent periods (amenorrhoea), menopausal anxiety and postpartum depression; being sold as a traditional medicine for 30 years with a safe history (Fierascu, 2019). In particular, motherwort has a documented history spanning over 400 years as a tea, made from the leaves and flowers for “nervous heart complaints" (EMA, 2018).

🌸🌱If your doctor has ruled out an organic cause but palpitations remain, a cup of motherwort tea may help to reduce anxiety or

the worry that stops you from sleep. With a mildly sedative action, you should take the tea when simply resting at home.

🌸🌱 To enjoy as a relaxing tea use the dried aerial parts (leaf and flower). The EMA reports a typical dosage for of 1-2 tsps (2-4 grams) of the dried herb. Steep for 10 minutes, covered. It can be quite bitter so you may wish to add a little honey to sweeten. Enjoy up to three times a day, for a maximum of four weeks.

A Deep Dive into Phytochemistry

Having a diverse range of phytochemicals presents a complex biological activity. Most notable are flavonoids, phenolic acids, iridoid glycosides and alkaloids.

Most herbs contain a variety flavonoids and phenolic acids which provide antioxidant (AO) and anti-inflammatory (AI) actions. AOs stop damage to tissues, repair cells and mop up waste to maintain healthy structures; damage can be produced both intrinsically, as in respiration (the production of a reactive form of oxygen is which must be reduced to hydrogen peroxide) or extrinsic (from our environment). While inflammation is a necessary mechanism (an immune response and blood clotting amongst others), in excess, it can also lead to cellular damage and excess waste accumulation; inflammatory environments support chronic dis-ease and anti-inflammatory actions are the antidote!

🌸🌱The flavonoids contained in motherwort include: kaempferol, apigenin, and quercetin, as well as hyperoside and rutin (which are basically quercetin with a sugar attached).

🌸🌱Phenolic acids found in Motherwort include: caffeic acid (a hydroxycinnamic acid) and derivatives like ferulic acid (a methylated hydroxycinnamic acid), chlorogenic acid (an ester of caffeic and quincic acid), and cichoric acid (a caffeic acid derivative, also found in Echinacea spp.).

🌸🌱Iridoid glycosides taste bitter and are thought to contribute to its sedative, anxiolytic (anti-anxiety), and anti-spasmodic actions, hence its traditional use for nervous tension. Some notable iridoid glycosides include: galiridoside, harpagide, aucuboside, ajugol (also known as leonuride); by adding an additional chemical group (-COCH3), you get ajugoside..

🌸🌱Leonurine (sounds similar to leonuride) is a specific alkaloid found in Motherwort. Being an alkaloid, it contains nitrogen in the form of a guanidine group (one carbon bonded to three nitrogens, with one having a double bond). The special structure of the guanidine group gives it a positive charge (it readily picks up protons, which have a positive charge), making it attractive to negative charges. Proteins, receptors and ion channels are often negatively charged, for example glutamate. Because guandiumium ions can form strong bonds they can influence the function of a channel or receptor by blocking, affecting flow or altering the signal. For example, NMDA receptors which bind to glutamate, the brains ‘on’ chemical, require an influx of calcium to aid plasticity. Or binding to GABA which can ameliorate depression or improve cognitive function. Binding to calcium channels can cause vasodilation, muscle contraction and tone, include stimulating uterine muscle and why it can promote menstrual flow used to bring on delayed periods or help prevent excessive bleeding post birth (postpartum haemorrhage).

Leonurine’s uniqueness provides multifaceted actions. Siyu et al. (2024) reviewed the effects of Leonurine, stating that it has potential for atherosclerosis, myocardial infarction, cardiac fibrosis, ischemic stroke and neurological conditions. A rat study by Li et al, (2017) showed Leonurine's promising effects in reducing rheumatoid arthritis-like symptoms. It appears to work by switching off inflammatory signals and their pathways (like IL-1β, IL-6, IL-8, and TNFα), reducing enzymes that break down joint tissue, and preventing further damage. Essentially, leonurine helped to calm the inflammatory response, leading to less joint inflammation and damage.

🌸🌱Terpenes: Sesquiterpenes include caryophyllene and humulene, although these are more commonly found in cannabis or hops, respectively. Monoterpenes include pinene and borneol, which are anti-inflammatory (AI), antioxidant (AO), and bitter, stimulating digestion and increasing liver function. Interestingly, the triterpene ursolic acid was also found to be cardioprotective, suppressing the generation of free radicals in the mitochondria—our energy-making cells, which we spoke about earlier. It may even have weak antimicrobial activity, especially against Staphylococcus aureus strain (a potential etiological agent of infective endocarditis), and antiviral potential, as do the other phenolic acids.

🌸🌱Furanic labdane diterpenes, such as Leosibirin, also contribute to Motherwort's anti-inflammatory and cardioprotective properties.

Cautions

It is best avoided by those with organic heart disease or low blood pressure, given the actions of this herb. Avoid in pregnancy and lactation as it acts on the uterine muscle. Avoid taking any herbal supplements alongside pharmaceutical medications as interactions could occur. Herbal medicine should not be used as a replacement for conventional medicine; always seek advice from your GP or a medical herbalist.

References

European Medicines Agency (2018) Assessment report on Leonurus cardiaca L., herba. Available at: https://www.ema.europa.eu/documents/herbal-report/final-assessment-report-leonurus-cardiaca-l-herba_en.pdf

Fierascu RC, Fierascu I, Ortan A et al. (2019) 'Leonurus cardiaca L. as a Source of Bioactive Compounds: An Update of the European Medicines Agency Assessment Report' Biomed Res Int. 17;2019:4303215. Available at: https://doi.org/10.1155/2019/4303215.

Nan Li, Qiang Xu, Qingping Liu et al. (2017) 'Leonurine attenuates fibroblast-like synoviocyte-mediated synovial inflammation and joint destruction in rheumatoid arthritis,' Rheumatology, 56, (8), 1417–1427. Available at: https://doi.org/10.1093/rheumatology/kex142

Siyu, L., Chen, S., Hailin, T et al. (2024) 'Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology,' Frontiers in Pharmacology, 15. Available at: https://doi.org/10.3389/fphar.2024.1428406