Other names: horse chestnut
Medicinal Actions: vasodilator, astringent, anti-oedema, anti-inflammatory
Qualities: soothing, cooling
Affinities: circulation (veins)
Constituents: aescin, hippocaesculin (saponins)
Safety issues: Saponins can be irritating, not to be applied to broken skin (e.g. bleeding piles)
Like many British children, I experienced a use of this wonderful tree long before I had anything to do with herbal medicine: conker bashing! Collecting shiny and hard conkers is a key memory of aumtums from my childhood, as is the recollection of how much it hurts when they smash into your fingers. This was one of the medicinal plants I was introduced to, and I remember the mild suprise upon learning it could be consumed internally, having heeded warnings from adults all my life that the conkers were poisonous. They are, of course, mildly toxic in large quantities, though the very constituents that cause the gastric upset (saponins) are also those that provide its medicinal action.
The palmate leaves have toothed leaflets with 5-7 points, spreading from a central stem. Mature horse chestnut trees grow to a height of around 40m and can live for up to 300 years. The bark is smooth and pinky-grey when young, which darkens and develops scaly plates with age. Twigs are hairless and stout; buds are oval, dark red, shiny and sticky. Appearing in May, individual flowers have 4–5 fringed petals, which are white with a pink flush at the base, arranged in a panicle. The conkers are actually the seed of the plant, used medicinally along with bark.
The traditional uses of this plant all centre around the venous circulatory system: bruises (external), piles (internal and external), phlebitis, chilblains, night cramp, orthostatic symptoms, stasis dermatitis/ulceration, and other conditions related to blood, e.g. uterine bleeding. Its anti-oedema effects make it useful for swollen ankles and to reduce pressure of RSIs. Its actions are basically the same as Ruscus aculeatus, or butcher’s broom.
Modern research supports its use as a venous tonic, for example in one clinical trial it was found to reduce the risk of DVT. Its ability to reduce chronic venous insufficiency is due in part to the action of aescin, which has various effects on venous endothelial cells, including making them more permeable to calcium ions. Externally, it can be applied to haemorroids in an aloe vera gel with a few drops of cypress or blue chamomile essential oil, though shouldn't really be used on broken skin i.e. bleeding piles.