How It Works
Bottom Line: Horse chestnut has been shown to be effective for treating chronic venous insufficiency, but its long-term health effects (more than three months) are not known. There is no evidence that it can treat any other medical conditions, such as varicose veins.
Horse chestnut is a seed extract. One of its main active components is aescin, which may reduce inflammation and increase the tone of veins. It also reduces the release of enzymes, which is typically increased in chronic diseases of the vein. Other compounds in horse chestnut generally increase the tone of blood vessels and decrease their permeability. Another compound called aesculetin may act as an anticoagulant and blood thinner, and is therefore often excluded from over-the-counter horse chestnut products.
Purported Uses
To treat circulatory disorders such as chronic venous insufficiency
Several clinical trials support this use for up to three months, but no clinical trials have tested the long-term use of this herb.
To treat diarrhea
No scientific evidence supports this use.
To treat hemorrhoids
No scientific evidence supports this use.
To treat phlebitis
No scientific evidence supports this use.
To treat varicose veins
No scientific evidence supports this use.
Research Evidence
Chronic venous insufficiency:
Researchers carried out a meta-analysis (systematic review) of all the randomized, controlled trials that used horse chestnut to treat chronic venous insufficiency. Overall, 13 clinical trials showed that patients who used horse chestnut had a significant decrease in leg edema (swelling) and symptoms such as leg pain, itching, tension, and fatigue. Because none of these clinical trials studied horse chestnut for more than 3 months, we can only conclude that short-term use of this herb is relatively safe and effective. Long-term studies are needed.
A large clinical trial compared horse chestnut to compression stocking therapy, which is a treatment for reducing leg edema (swelling) in patients with chronic venous insufficiency. After 12 weeks, patients taking horse chestnut had a similar reduction in leg edema to patients using the compression stocking therapy (about 45 ml), while patients taking a placebo pill had an increase in leg edema. These results indicate that horse chestnut is effective for this use, but again, we do not know how well it will work in the long-term (greater than 12 weeks).
Warnings
- Horse chestnut seed is classified by the FDA as an unsafe herb. Many of the compounds in horse chestnut are considered to be toxic.
- This product is regulated by the F.D.A. as a dietary supplement. Unlike approved drugs, supplements are not required to be manufactured under specific standardized conditions. This product may not contain the labeled amount or may be contaminated. In addition, it may not have been tested for safety or effectiveness.
Do Not Take If
You are taking warfarin, aspirin, or other blood thinners (Horse chestnut products that contain aesculin may increase the risk of bleeding. Check to make sure that your horse chestnut product is aesculin-free)
You have liver or kidney problems.
Side Effects
Stomach upset
Nausea and vomiting
Chestnut poisoning: Diarrhea, muscle twitching, dilated pupils, depression, and paralysis can occur after high doses of horse chestnut.
Special Point
Over-the-counter products should be standardized to 50 mg of aescin (the active ingredient) and free from aesculin, which can act as a blood thinner.
Scientific Name
Aesculus hippocastanum
Common Name
Chestnut, marron europeen, escine, aescin
Brand Name
Venastat™
Clinical Summary
Derived from the seeds of the tree. This herb contains several active components. Commercial products should be standardized to 50 mg of aescin and free from aesculin, a hydroxycoumarin. Studies have shown clinical efficacy in chronic venous insufficiency
(7) (8) (9), but no data support the reversal of varicose veins. At recommended doses no significant adverse reactions are reported. Patients with compromised renal or hepatic function should not consume horse chestnut products. Horse chestnut extracts that contain aesculin may interact with anticoagulants and increase the risk of bleeding
(4).
Purported uses
- Circulatory disorders
- Diarrhea
- Hemorrhoids
- Phlebitis
- Varicose veins
Constituents
Coumarins: Aesculetin, fraxin, scopolin
Flavonoids: Flavonol (kaempferol, quercetin) glycosides including astragalin, isoquercetrin, rutin, and leucocyanidin
Saponins: Several saponins collectively referred to as aescin
Tannins
Other constituents: Allantoin, amino acids, choline, citric acid, phytosterol
(1)
Mechanism of Action
Anti-inflammatory actions have been documented for the saponins (aescin). Aescin reduces transcapillary filtration of water and protein and increases venous tone related to increased prostaglandin F2 alpha (vasoconstrictor). It stabilizes cholesterol-containing membranes of lysosomes and limits the release of enzymes, which is typically increased in chronic pathologic conditions of the vein. It also improves vascular resistance and aids toning of vein walls
(3). Aesculetin (esculin) is a hydroxycoumarin, which may increase bleeding time. The triterpene glycosides and steroid saponins decrease venous capillary permeability and appear to have a tonic effect on the circulatory system
(4).
Pharmacokinetics
Orally administered aescin has an absorption half-life of about 1 hour and an elimination half-life of about 20 hours.
(5)
Warnings
Horse chestnut seed is classified by the FDA as an unsafe herb. Many of the constituents are considered toxic, such as the glycosides and the saponins.
(2)
Contraindications
Should not be consumed by patients with hepatic or renal insufficiency.
Adverse Reactions
Common: GI upset, nausea, and vomiting
Toxicity: (Chestnut poisoning) Diarrhea, muscle twitching, dilated pupils, depression, and paralysis
Herb-Drug Interactions
Anticoagulants / Antiplatelets: Horse chestnet may have an additive anticoagulant effect due to aesculin, a hydroxycoumarin.
No drug interactions with Venastat™ (does not contain aesculin) have been reported.
(6)
Lab Interactions
May prolong APTT, PTT, INR
Literature Summary and Critique
Pittler MH, et al. Horse-chestnut seed extract for chronic venous insufficiency. A criteria-based systematic review. Arch Dermatol 1998;134:1356-60.A criteria-based systematic review of double-blind, randomized, controlled trials of oral horse chestnut extract for patients with chronic venous insufficiency. Thirteen studies (8 placebo-controlled) with a total of 1083 patients were reviewed. Trial length ranged from 4 to 12 weeks with a total of 63 dropouts. Use of horse chestnut seed extract was associated with a statistically significant decrease in lower-leg volume and reduction of leg circumference at the calf and ankle as compared to placebo. Symptoms such as leg pain, pruritus, fatigue, and tenseness were also reduced. Adverse effects were mild and comparable to placebo. It was the author's conclusion that short-term, symptomatic use of horse chestnut appears to be safe, but long-term studies are necessary.
Diehm C, et al. Comparison of leg compression stocking and oral horse-chestnut seed extract therapy in patients with chronic venous insufficiency. Lancet 1996;347:292-4.Comparison of therapies in 240 patients with chronic venous insufficiency. Patients were treated over a period of 12 weeks in a randomized, partially blinded, placebo-controlled, parallel study design. Lower leg volume of the more severely affected limb decreased on average by 43.8 ml with horse chestnut and 46.7 ml with compression therapy, while it increased by 9.8 ml with placebo after 12 weeks of therapy. These results indicate that compression stocking therapy and horse chestnut therapy are alternative therapies for the effective treatment of patients with edema resulting from chronic venous insufficiency.
References
