Horse chestnut effective in chronic venous insufficiency
As part of the Journal of the American Medical Association
yearly theme issue on alternative medicine, Archives
of Dermatology (a sister journal) published a noteworthy
review article on horse chestnut (Aesculus hippocastanum L.,
Hippocastanaceae). Derived from the seed of a fragrant flowering
tree, horse chestnut extract is widely used in Germany for treating
chronic venous insufficiency (CVI). Individuals with CVI often
complain of an aching or tired feeling in their legs when standing
or walking, symptoms that are caused by edema (accumulation of
excess fluid) and inflammation of the veins. In this critical
review of 13 clinical studies, the authors found horse chestnut
superior to placebo and just as effective in improving the symptoms
of CVI as O-(ß-hydroxyethyl)-rutosides, a mixture of flavonoid
glycosides derived from buckwheat and other plants which is used
to improve capillary function. Another study suggested therapeutic
value equal to standard compression treatment, although this study
was not double-blinded [Pittler and Ernst, 1998].
All of the studies chosen for this review were either placebo-controlled
or compared the effects of horse chestnut to reference medications.
In the eight placebo-controlled studies, subjects took one capsule
twice daily of horse chestnut extract standardized to 50 to 75
mg aescin over a period of 20 days to two months. The pooled results
showed that horse chestnut dramatically reduced edema, measured
as a reduction in lower-leg volume and leg circumference at the
calf and ankle. Subjects reported less pain, fatigue, tenseness,
and pruritus (itching) in their legs by the end of treatment.
One study suggested a 22 percent decline in the capillary filtration
rate after use of horse chestnut. Positive results were evident
within two weeks in several of the studies, with benefits lasting
at least six weeks after treatment. Although there is no universally
accepted classification of CVI, most of the studies were consistent
in using a single classification system.
In five comparative studies, horse chestnut extract alleviated
edema just as effectively as O-(ß-hydroxyethyl)-rutosides.
Horse chestnut was associated with minor side effects in 0.9 percent
to 3 percent of subjects, including stomach upset, calf spasm,
dizziness, nausea, headache, and itching. Other symptomatic treatment
options can cause stomach upset, nausea, and allergic skin reactions,
and compression therapy has been linked to skin necrosis (death
of skin cells) and ulcers.
One of the main active constituents of horse chestnut is the
triterpenic saponin aescin (also spelled escin), which has been
shown to protect the integrity of veins and capillaries in
vitro by inhibiting the enzymes elastase and hyaluronidase.
Horse chestnut may also reduce levels of leukocytes and proteoglycan
hydrolases, which tend to be abnormally high in CVI-affected limbs.
Using electron microscopy, researchers have confirmed a marked
reduction in vascular leakage in animals after treatment with
the botanical extract. Although laboratory studies show that horse
chestnut increases venous pressure and flow, researchers have
not yet confirmed these positive effects on vascular tone in humans.
- Krista Morien (HRF)
[Pittler MH, Ernst E. Horse-chestnut
seed extract for chronic venous insufficiency: a criteria-based
systematic review. Arch Dermatol 1998; 134: 1356-1360.] |
