General Description
The white willow is a deciduous tree native to Europe and introduced
throughout temperate regions of North America. Growing up to 25
meters in height, white willow usually flowers in early spring,
bearing small cylindrical catkins, with male and female flowers
on separate trees. The tree has long, narrow, lanceolate leaves,
covered with short hairs on both sides. The fruit consists of small
capsules filled with light, downy seeds, which are readily transported
via wind. White willow has a rough grayish bark, which is used medicinally.
Health Applications
- Pain relief
- Fever reduction
History and Traditional Use
The bark of various willow species has been used medicinally throughout
history. It is mentioned in ancient Greek, Egyptian, and Assyrian
writings, and was used as an analgesic by Hippocrates, Dioscorides,
and other ancient physicians.1 The famous 17th
Century British herbalist Nicholas Culpeper recommended willow bark
for "drying up humours" and a variety of topical applications.2
Extracts of the bark were first tested in the 1820s, when the active
component, salicin, was first isolated and identified. Salicylic
acid was first derived from salicin by the German scientist Gerland
in 1852, leading to the development of acetylsalicylic acid a year
later by the French chemist Gerhardt.3 Acetylsalicylic
acid was rediscovered in 1897 by German chemist Felix Hoffman, and
was mass-produced by the German company Bayer under the commercial
name of "aspirin" for treatment of fever and rheumatism.
Chemical Composition
The principal constituent of white willow bark is a glycoside
compound known as salicin, which has analgesic and anti-inflammatory
properties.
Contemporary Uses
Modern herbalists commonly recommend white willow bark as a natural
aspirin alternative. Germany's Commission E lists white willow
bark as an approved herb for fever, headaches, and rheumatic ailments.4
One study conducted on 210 patients found willow bark extract
to be significantly more effective than a placebo in the treatment
of low back pain.5
Dosage/Toxicity
The recommended dosage for white willow bark varies according
to its salicin content. Commission E recommends a dosage corresponding
to 60 to 120 mg of salicin per day.4 Although
the herb has no known side effects at this dosage range, some
individuals may experience allergic responses.5
Because it is closely related to aspirin, white willow bark is
not recommended in cases where aspirin is contraindicated, such
as people with ulcers or children with fevers. |
