4 November 2019


Aesculin is a

coumarin glucoside found in horse chestnut (Aesculus hippocastanum),There are other species that can produce this toxin, such as California buckeye (Aesculus californica) and prickly box (Bursaria spinosa). Horse chestnuts (Aesculus species) are different from the edible chestnut (Castanea species) (1)

Seeds, barks, flowers and leaves of horse chestnut are used in medicine for the vasoprotective properties of aesculin; it is widely used for treating, among others, varicose veins, hemorrhoids, and swollen veins (phlebitis), venous insufficiency, eczema, menstrual pain, soft tissue swelling from bone fracture and sprains, cough, arthritis, and joint pain. Aesculin this the blood and prevent fluid to escape from veins and capillaries. In addition, it promotes fluid loss through the urine to help prevent water retention (edema) (2) (3)

Picture 1: horse chestnut tree close to the Fyris river in Uppsala, Sweden.
Picture 2: fallen horse chestnuts

Besides its medical use, raw horse chestnut seed, bark, flower, and leaf are can cause stomacache, kidney problems, muscle twitching, weakness, loss of coordination, enlarged eye pupils, vomiting, diarrhea, depression, paralysis, and stupor. If eaten by accident, medical attention is required inmediately to prevent worse symptoms to happen; it can even cause death.

Children are poisoned by drinking a tea made from the leaves or eating seeds. It can even cause death when taken by mouth by adults or children. Cattle, sheep, horses, swine, chickens can also be poisoned. For these animals, they usually get poisoned when the animal eat the leaves and sprouts of the buckeye as they generally leaf out before other plants in the spring. (4)

A specific therapy is not yet there for this type of poisoning. When ingested, laxatives can be administrated to remove the toxin as soon as possible from the gastrointestinal system. Therapy can be accompanied by supportive intravenous fluid therapy with calcium gluconate and dextrose.

Picture 3: horse chestnut tree and ESR9 (Carina Schönsee) during her secondment in Sweden.



  1. Guide to Poisonous Plants – College of Veterinary Medicine and Biomedical Sciences – Colorado State University [Internet]. [cited 2019 Oct 30]. Available from: https://csuvth.colostate.edu/poisonous_plants/Plants/Details/62
  2. Horse Chestnut: Uses, Side Effects, Interactions, Dosage, and Warning [Internet]. [cited 2019 Nov 1]. Available from: https://www.webmd.com/vitamins/ai/ingredientmono-1055/horse-chestnut
  3. Horse-Chestnut Seed Extract for Chronic Venous Insufficiency: A Criteria-Based Systematic Review | Surgery | JAMA Dermatology | JAMA Network [Internet]. [cited 2019 Nov 1]. Available from: https://jamanetwork.com/journals/jamadermatology/article-abstract/189561
  4. Aesculus hippocastanum, horse chestnut - THE POISON GARDEN website [Internet]. [cited 2019 Oct 30]. Available from: http://www.thepoisongarden.co.uk/atoz/aesculus_hippocastanum.htm


Taken by Inés Rodríguez Leal (ESR1) in Uppsala, Sweden (October 2019)