General Description
Nettle is a perennial plant found in damp woods and grassy areas
in temperate regions throughout the world. It has a creeping root
which produces a bristled stem growing from 1 to 2 meters in height.
The plant has deep green, serrated, heart-shaped leaves, which are
covered on the undersides with fine hairs that cause a burning sensation
upon contact with the skin. Nettle flowers in mid to late summer,
bearing pale green, incomplete flowers, with male and female often
growing on separate plants. The root and leaves are used medicinally.
Health Applications
- Prostate enlargement
- Urinary tract health
- Kidney stones
- Arthritis
- Hayfever
History and Traditional Use
Nettle has a long history of use as a food, textile, and medicinal
herb. Fabric made from nettle has been discovered by archeologists
at a Bronze Age burial site in Denmark.1 Nettle
cloth was used extensively in Germany and Austria during World War
I, when cotton was in short supply. In 1916 alone, 2.7 million kilograms
of nettle were collected in Germany to make cloth.2
The medicinal use of nettle dates back to ancient times, when bunches
of nettle were used to slap paralized limbs.1
In the 17th Century, British herbalist Nicholas Culpeper prescribed
the juice of nettle leaves to heal sores in the mouth, while he
prescribed decoctions of the seeds as a remedy "against the stinging
of venomous creatures, the biting of mad dogs," and several poisonous
plants.3 Chemical
Composition
Analyses of nettle leaves have revealed over 20 chemical constituents;
however, the compound responsible for the pain from contact with
nettle has not been determined.4 Rich in chlorophyll,
vitamin C, and beta-carotene, nettle leaves also contain calcium
and potassium salts and silicic acid. The root contains beta sitosterol
in free forms and as glycosides, as well as a compound known as
scopoletin.5
Contemporary Uses
Germany's Commission E lists nettle leaf as an approved herb for
external use in rheumatic ailments and for internal use in therapy
for inflammation of the lower urinary tract and the prevention
and treatment of kidney stones. The root is approved for treatment
of benign prostatic hyperplasia (BPH).5 In
vitro studies indicate that nettle leaves have anti-inflammatory
properties,6,7 and one small study found topical
application of nettle leaves to be significantly more effective
than placebo in treatment of osteoarthritis.8
In vitro and animal studies suggest that compounds in nettle root
may be useful in treatment of BPH 9-11 and
possibly prostate cancer;12 however, these
effects have not been demonstrated in human subjects. One preliminary
study suggests that nettle leaves may be helpful in treatment
of hayfever,13 but further studies are needed
to determine the herb's usefulness in this area.
Dosage/Toxicity
The daily dosages approved by Commission E are 8 to 12 grams of
fresh or dried nettle leaves and 4 to 6 grams of the root.5
Nettle has very low toxicity and appears to be safe at these doses.
While there are no known side effects associated with the use
of nettle leaves, mild gastrointestinal upset has occasionally
been reported with the use of the root.5 |
