Botanical Name :Aesculus hippocastanum
Species: A. hippocastanum
Common Name:horse-chestnut or conker tree.
Habitat :Aesculus hippocastanum is native to a small area in the Pindus Mountains mixed forests and Balkan mixed forests of South East Europe. It is widely cultivated in streets and parks throughout the temperate world.
A. hippocastanum is a decidious tree.It grows to 36 metres (118 ft) tall, with a domed crown of stout branches; on old trees the outer branches often pendulous with curled-up tips. The leaves are opposite and palmately compound, with 5–7 leaflets; each leaflet is 13–30 cm long, making the whole leaf up to 60 cm across, with a 7–20 cm petiole. The leaf scars left on twigs after the leaves have fallen have a distinctive horseshoe shape, complete with seven “nails”.It is in flower in May, and the seeds ripen in September. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Bees.The flowers are usually white with a small red spot; they are produced in spring in erect panicles 10–30 cm tall with about 20–50 flowers on each panicle. Usually only 1–5 fruit develop on each panicle; the shell is a green, spiky capsule containing one (rarely two or three) nut-like seeds called conkers or horse-chestnuts. Each conker is 2–4 cm diameter, glossy nut-brown with a whitish scar at the base.
It is hardy to zone 3 and is frost tender.
Prefers a deep loamy well-drained soil but is not too fussy tolerating poorer drier soils. Tolerates exposed positions and atmospheric pollution. A very ornamental and fast-growing tree, it succeeds in most areas of Britain but grows best in eastern and south-eastern England. Trees are very hardy when dormant, but the young growth in spring can be damaged by late frosts. The flowers have a delicate honey-like perfume. Trees are tolerant of drastic cutting back and can be severely lopped. They are prone to suddenly losing old heavy branches. The tree comes into bearing within 20 years from seed. Most members of this genus transplant easily, even when fairly large.
Seed – best sown outdoors or in a cold frame as soon as it is ripe. The seed germinates almost immediately and must be given protection from severe weather. The seed has a very limited viability and must not be allowed to dry out. Stored seed should be soaked for 24 hours prior to sowing and even after this may still not be viable. It is best to sow the seed with its ‘scar’ downwards. If sowing the seed in a cold frame, pot up the seedlings in early spring and plant them out into their permanent positions in the summer.
Edible Parts: Seed.
Edible Uses: Coffee.
The roasted seed is used as a coffee substitute. Seed – cooked. It can be dried, ground into a powder and used as a gruel. The seed is quite large, about 3cm in diameter, and is easily harvested. It is usually produced in abundance in Britain. Unfortunately the seed is also rich in saponins, these must be removed before it can be used as a food and this process also removes many of the minerals and vitamins, leaving behind mainly starch. See also the notes above on toxicity. The seed contains up to 40% water, 8 – 11% protein and 8 – 26% toxic saponins. The following notes apply to A. californica, but are probably also relevant here:- The seed needs to be leached of toxins before it becomes safe to eat – the Indians would do this by slow-roasting the nuts (which would have rendered the saponins harmless) and then cutting them into thin slices, putting them into a cloth bag and rinsing them in a stream for 2 – 5 days.
Horse chestnut is an astringent, anti-inflammatory herb that helps to tone the vein walls which, when slack or distended, may become varicose, haemorrhoidal or otherwise problematic. The plant also reduces fluid retention by increasing the permeability of the capillaries and allowing the re-absorption of excess fluid back into the circulatory system. This plant is potentially toxic if ingested and should not be used internally without professional supervision. Alterative, analgesic, haemostatic and vulnerary. The bark is anti-inflammatory, astringent, diuretic, febrifuge, narcotic, tonic and vasoconstrictive. It is harvested in the spring and dried for later use. The plant is taken in small doses internally for the treatment of a wide range of venous diseases, including hardening of the arteries, varicose veins, phlebitis, leg ulcers, haemorrhoids and frostbite. It is also made into a lotion or gel for external application. A tea made from the bark is used in the treatment of malaria and dysentery, externally in the treatment of lupus and skin ulcers. A tea made from the leaves is tonic and is used in the treatment of fevers and whooping cough. The pericarp is peripherally vasoconstrictive. The seeds are decongestant, expectorant and tonic. They have been used in the treatment of rheumatism, neuralgia and haemorrhoids. They are said to be narcotic and that 10 grains of the nut are equal to 3 grains of opium. An oil extracted from the seeds has been used externally as a treatment for rheumatism. A compound of the powdered roots is analgesic and has been used to treat chest pains. The buds are used in Bach flower remedies – the keywords for prescribing it are ‘Failure to learn by experience’, ‘Lack of observation in the lessons of life’ and hence ‘The need of repetition’. The flowers are used in Bach flower remedies – the keywords for prescribing it are ‘Persistent unwanted thoughts’ and ‘Mental arguments and conversations’.
Dye; Soap; Starch; Tannin; Wood.
Saponins in the seed are used as a soap substitute. The saponins can be easily obtained by chopping the seed into small pieces and infusing them in hot water. This water can then be used for washing the body, clothes etc. Its main drawback is a lingering odour of horse chestnuts. The seed contains variable amounts of saponins, up to a maximum of 10%. A starch obtained from the seed is used in laundering. The bark and other parts of the plant contain tannin, but the quantities are not given. A yellow dye is obtained from the bark. The flowers contain the dyestuff quercetin. Wood – soft, light, not durable. Of little commercial value, it is used for furniture, boxes, charcoal.
Flowers: FreshThe flowers have a delicate honey-like perfume.
Known Hazards:The seed is rich in saponins. Although poisonous, saponins are poorly absorbed by the human body and so most pass through without harm. Saponins are quite bitter and can be found in many common foods such as some beans. They can be removed by carefully leaching the seed or flour in running water. Thorough cooking, and perhaps changing the cooking water once, will also normally remove most of them. However, it is not advisable to eat large quantities of food that contain saponins. Saponins are much more toxic to some creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish.
Safety in medical use:
Two preparations are considered; whole horsechestnut extract (whole HCE) and purified ?-aescin. Historically, whole HCE has been used both for oral and IV routes (as of year 2001). The rate of adverse effects are low, in a large German study, 0.6 %, consisting mainly of gastrointestinal symptoms. Dizziness, headache and itching have been reported. One serious safety issue is rare cases of acute anaphylactic reactions, presumably in a context of whole HCE. Purified ?-aescin would be expected to have a better safety profile.
Another is the risk of acute renal failure, “when patients, who had undergone cardiac surgery were given high doses of horse chestnut extract i.v. for postoperative oedema. The phenomenon was dose dependent as no alteration in renal function was recorded with 340 ?g kg?1, mild renal function impairment developed with 360 ?g kg?1 and acute renal failure with 510 ?g kg?1”. This almost certainly took place in a context of whole HCE.
Three clinical trials were since performed to assess the effects of aescin on renal function. A total of 83 subjects were studied; 18 healthy volunteers given 10 or 20 mg iv. for 6 days, 40 in-patients with normal renal function given 10 mg iv. two times per day (except two children given 0.2 mg/kg), 12 patients with with cerebral oedema and normal renal function given a massive iv. dose on the day of surgery (49.2 ± 19.3 mg) and 15.4 ± 9.4 mg daily for the following 10 days and 13 patients with impaired renal function due to glomerulonephritis or pyelonephritis, who were given 20–25 mg iv. daily for 6 days. “In all studies renal function was monitored daily resorting to the usual tests of renal function: BUN, serum creatinine, creatinine clearance, urinalysis. In a selected number of cases paraaminohippurate and labelled EDTA clearance were also measured. No signs of development of renal impairment in the patients with normal renal function or of worsening of renal function in the patients with renal impairment were recorded.” It is concluded that aescin has excellent tolerability in a clinical setting.
Raw Horse Chestnut seed, leaf, bark and flower are toxic due to the presence of esculin and should not be ingested. Horse chestnut seed is classified by the FDA as an unsafe herb. The glycoside and saponin constituents are considered toxic.
Aesculus hippocastanum is used in Bach flower remedies. When the buds are used it is referred to as “chestnut bud” and when the flowers are used it is referred to as “white chestnut”.
Quercetin 3,4′-diglucoside, a flavonol glycoside can also be found in horse chestnut seeds
The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.