The Sunlight Experiment

Compound Monograph

Ursolic acid

Ursolic acid — a pentacyclic triterpene acid found in hawthorn, bearberry, gotu kola and elder, best characterised in these herbs for its contribution to hawthorn's coronary-dilating and heart-strengthening (inotropic) activity.

Work in progress

Classification

Ursolic acid is a pentacyclic triterpene (ursane) acid, part of the terpenoids class. The largest class of plant compounds, built from five-carbon isoprene units — the essential-oil aromatics, resins, bitter principles, saponins, and plant sterols.

Terpenoids Triterpenes

Where Does It Come From? (13)

Ursolic acid is a naturally occurring pentacyclic triterpene (ursane) acid, found in Hawthorn, Bearberry, Gotu kola and 10 other sources. It is well tolerated orally (low toxicity).

Apple peel Bay Bean Canavalia rosea Bearberry Arctostaphylos uva-ursi Catnip Nepeta cataria Elderberry Sambucus nigra Gotu Kola Centella asiatica Guamura Cecropia mexicana Hawthorn Crataegus oxyacantha Holy Basil Ocimum tenuiflorum Melissa Melissa officinalis Motherwort Leonurus cardiaca Rosemary Rosmarinus officinalis Yerba Maté Ilex paraguariensis

Research & Evidence

Ursolic acid is a pentacyclic triterpene acid that turns up in the leaves and other parts of several medicinal plants. In the source-herb monographs in this database its best-characterised role is cardiovascular, where it is named as one of the active triterpene acids of hawthorn:

  • Coronary artery dilation — hawthorn’s ability to widen the coronary arteries has been attributed to its crataegolic acid and ursolic acid content, together with various flavonoids (such as vitexin-2”-O-rhamnoside, luteolin-7-glucoside, hyperoside, rutin and vitexin) and the oligomeric procyanidins 1Reference 1Occhiuto et al. · 1986Comparative study of the cardiovascular activity of shoots, leaves and flowers of Crataegus oxyacantha: 2.
  • Positive inotropy (heart-strengthening) — the positively inotropic action of hawthorn — improving the force of cardiac contraction — was likewise found in an early study to be due to the crataegolic acid, ursolic acid and vitexin-2”-O-rhamnoside content 1Reference 1Occhiuto et al. · 1986Comparative study of the cardiovascular activity of shoots, leaves and flowers of Crataegus oxyacantha: 2. In hawthorn’s leaves and flowers, ursolic acid is one of the triterpene acids present at up to about 0.6% 2Reference 2Hoffmann · 2003Medical Herbalism: The Science and Practice of Herbal Medicine.

Beyond hawthorn, ursolic acid is reported as a contributing constituent in other herbs:

  • In bearberry, ursolic acid is listed among the triterpenes (with β-amyrin) that support the herb’s antibacterial activity, alongside arbutin, tannins and flavonoids 3Reference 3Uva Ursi (Arctostaphylos uva-ursi): A Re · 2015ReviewAlternative and Complementary Therapies, 21(4), 180–181. doi:10.1089/act.2015.29013.uvaView study →.
  • In gotu kola, ursolic acid appears among the triterpene saponosides that make up much of that herb’s phytochemistry 4,5Reference 4Ilkay Erdogan Orhan · 2012Centella asiatica (L.) Urban: From Traditional Medicine to Modern Medicine with Neuroprotective PotentialView study →Reference 5Bone K · 2013Principles and Practice of Phytotherapy.
  • Elder also contains ursolic acid among its triterpenoids, though the source page does not tie a specific activity to it.

A general caution from the hawthorn page is worth carrying over to any discussion of isolated triterpenes: several studies using single isolated hawthorn constituents showed little or no activity compared with the whole-herb extract, which consistently produced broad cardiovascular effects 2Reference 2Hoffmann · 2003Medical Herbalism: The Science and Practice of Herbal Medicine. In other words, ursolic acid appears to act as part of a constituent matrix rather than as a stand-alone drug. The references below are the studies cited on the source-herb pages that genuinely pertain to ursolic acid.

Toxicity & Safety

Ursolic acid is flagged here as low-toxicity. It occurs naturally in many edible and medicinal plants — including the waxy skins of fruits — and the herbs that supply it in this database are themselves well tolerated: hawthorn has no reported long-term adverse effects in the therapeutic range and is considered suitable for long-term cardiovascular use, and gotu kola is regarded as generally safe and even used as a food in several countries. The cautions for these herbs relate to the whole plant and its other constituents (for example hawthorn’s potential to enhance the action of cardiac-glycoside drugs) rather than to ursolic acid specifically.

References

  1. Occhiuto, F., Circosta, C., Costa, R., Briguglio, F., & Tommasini, A. (1986). Comparative study of the cardiovascular activity of shoots, leaves and flowers of Crataegus oxyacantha: 2. Action of extracts and isolated pure active principles on the isolated rabbit heart. Plantes Médicinales et Phytothérapie, 20, 52–63.
  2. Hoffmann, D. (2003). Medical Herbalism: The Science and Practice of Herbal Medicine. Rochester, VT: Healing Arts Press.
  3. Uva Ursi (Arctostaphylos uva-ursi): A Review of Clinical Therapeutics by the American Herbal Pharmacopeia. (2015). Alternative and Complementary Therapies, 21(4), 180–181. doi:10.1089/act.2015.29013.uva
  4. Ilkay Erdogan Orhan. (2012). Centella asiatica (L.) Urban: From Traditional Medicine to Modern Medicine with Neuroprotective Potential. Evidence-Based Complementary and Alternative Medicine. doi:10.1155/2012/946259
  5. Bone K, Mills S. (2013). Principles and Practice of Phytotherapy. Elsevier Health, China.