Botanical Description
Single stalk plants standing up to 120 cm tall with heart-shaped, tooth-edged leaves. The stems are square. The flowers are white with a green cast and are borne in clusters from the leaf axils. Flowers in the male plant are more yellowish. The leaves are covered with stinging hairs as well as softer, non-stinging hairs. To differentiate them from Urtica urens (small nettle), note that the flowering panicles are longer than the leaf petioles in U. dioica.
A common adulterant is the look alike plant Lamium album (white deadnettle), which does not have stinging hairs. The leaf margins of this plant are less regularly saw-toothed as well.
Parts Used
herba, radix
Historical Uses
Constituents
agglutinin (UDA): this protein is highly acid and heat resistant
and therefore probably is orally absorbed (Willer, Wagner &
Schecklies 1991)
beta-sitosterol
Medicinal Actions
mildly anti-inflammatory
hypocholesterolemic (Miettinen, et al. 1996)
carotenoids: beta-carotene, xanthophylls
chlorophyll
enzymes
flavonoids, including glycosides of quercetin, kaempferol
and rhamnetin (Wichtl & Bisset 1994)
glucoquinone: possibly hypoglycemic (Leung 1980)
isolectins
minerals: iron, selenium, etc.
nettle poison: Found in the stinging hairs of the plant, this
is made up of formic acid, histamine, a resinic acid-like substance
and volatile acids.
pro-inflammatory
irrititant
oleanolic acid
polysaccharides
scopoletin
tannins
caffeic malic acid: anti-inflammatory (Obertreis, et al. 1996)
Notes: Active constituent(s) remain unknown but are apparently
water soluble (Goetz 1989). For general information on constituents,
refer to Leung 1980, Tyler 1994 and Wichtl & Bisset 1994.
Medicinal Uses
Medicinal Indications
allergic rhinitis (Mittman 1990)
benign prostatic hyperplasia
Useful to decrease residual volume and increase urine flow (Romics,
1987).
Useful to improve urine volume and flow, as well as favorably
alter SHBG binding (Vontobel, et al. 1985).
Useful in combination with Pygeum africanum cortex (Krzeski,
et al. 1993; Montanari, et al. 1991).
Use approved by German health officials at 4-6 g of the radix
used qd as infusion (cited in Tyler, 1994).
Conditions in which an aquaretic (mild diuretic) is indicated.
The use of Urtica dioica as an aquaretic in renal and cardiac
impairment has been approved by German health officials (cited
in Wichtl & Bisset 1994).
Many uses are cited for Urtica dioica in traditional
medicine which have not been verified by modern scientific methods.
These include:
osteoarthritis (Randall 1994)
edema due to venous insufficiency, congestive heart failure or
trauma
neuralgia (topical application)
rheumatic pain (topical application)
sciatica (topical)
tendinitis and sprains (topical)
anaphylactic shock (eat raw nettles, last ditch) (Note: Anaphylactic
shock is a life-threatening condition for which the use of this
herb cannot be recommended. Use of this herb may delay life-saving
treatment with epinephrine.)
hair loss (shampoo from infusion)
gout
insufficient lactation
hemorrhage
menorrhagia
Pharmacy:
Steamed (10-15 min) adult leaves with lemon juice and vinegar
can be used as a food (acid helps with mineral assimilation).
Note that the young leaves don't sting and thus don't need to
be steamed.
A drink could be made from lemonade, nettles and kelp.
tea: official German doses
radix: decoct 4-6 g qd for BPH (cited in Tyler 1994)
folia: infuse 4 g in 150 ml water tid (cited in Tyler 1994)
Commercial juice preparations.
Contraindications:
Hypersensitivity or allergy to Urtica spp.
Side Effects and Toxicity:
The fresh, adult leaves cause wheals due to stinging hairs.
This property is actually utilized medicinally, but care must
be taken in most situations.
It has been found to be mildly genotoxic (Graf, et al., 1994).
It has been found to be hyperglycemic in one study in rabbits
(Rom n-Ramos, et al. 1992)
Reported to cause minimal adverse effects on administration,
except occasional GI upset (Tyler, 1994).
References:
Barsom S, and Bettermann A (1979) "[Prostatic adenoma.
The conservative therapy with urtica extract]" ZFA Zeitschrift
fur Allgemeinmedizin 55(33):1947-50
Belaiche P and Lievoux O (1991) "Clinical studies on
the palliative treatment of prostatic adenoma with extract of
Urtica root" Phytother Res 5:267-9
Goetz P (1989) Zeitschrift fur Phytotherapie 10:175-8
Graf U, et al. (1994) "Genotoxicity testing of different
types of beverages in the Drosophilia wing Somatic Mutation and
Recombination Test" Food Chem Toxicol 32(5):423-30
Hirano T, Homma M and Oka K (1994) "Effects of stinging
nettle root extracts and their steroidal components on the Na+,
K+-ATPase of the benign prostatic hyperplasia" Planta
Med 60:30-3
Krzeski T, et al. (1993) "Combined extracts of Urtica
dioica and Pygeum africanum in the treatment of benign
prostatic hyperplasia: double-blind comparision of two doses"
Clin Ther 15(6):1011-20
Leung A (1980) Encyclopedia of Common Natural Ingredients
Used in Food, Drugs and Cosmetics (John Wiley & Sons)
Miettinen TA, Puska P, Gylling H, et al. (1996) "Reduction
of serum cholesterol with sitostanol-ester margarine in a mildly
hypercholesterolemic population" New England Journal of
Medicine 333:1308-12
Mills S (1992) Out of the Earth (New York: Viking)
p 496-9
Mittman P (1990) "Randomized, double-blind study of freeze-dried
Urtica diocia in the treatment of allergic rhinitis"
Planta Med 56:44-7
Montanari E, et al. (1991) "Phytotherapy of benign prostatic
hypertrophy (BPH) without complications" Der informierte
Arzt 6A:593-8
Obertreis B, Giller K, et al. (1996) "Antiphlogisitc
effects of Urtica dioica folia extract in comparison to caffeic
malic acid" Arzneim-Forsch 46:52-6
Randall CF (1994) "Stinging nettles for osteoarthritis
pain of the hip" (letter) Br J Gen Pract Nov:533-4
Roman-Ramos, R., et al. (1992) "Hypoglycemic effect of
plants used in Mexico as antidiabetics" Arch Med Res
23(1):59-64
Romics I (1987) "Observations with Bazoton in the management
of prostatic hyperplasia" Int Urol Nephrol 19(3):293-7
Schmidt K (1983) "Effect of radix urticae extract and
its several secondary tracts on blood SHBG in benign prostate
hyperplasia" Fortschr Med 101(15):713-6 (in German)
Tyler V (1994) Herbs of Choice: The Therapeutic Use of
Phytomedicinals (Pharmaceutical Products Press)
Vontobel, H., et al. (1985) "Results of a double-blind
study on the effectiveness of ERU (extractum radicis urticae)
capsules in conservative treatment of benign prostatic hyperplasia"
Urologe [A]:49-51 (in German)
Weiss RF (1985) Herbal Medicine (Gothenburg: Ab Arcanum
and Beaconsfield: Beaconsfield Publishers), pp. 255, 261-2
Wichtl M ,ed. (German edition), Bisset NG, ed and trans (English
edition) (1994) Herbal Drugs and Phytopharmaceuticals
(Medpharm Scientific Publishers, CRC Press), pp. 505-9
Willer F, Wagner H and Schecklies E (1991) Deutsche ApothekerZeitung 131:1217-21
Please Note: The information contained in this section of the web site is directed toward people with technical knowledge in the botanical medicine field. We provide this information as a service to naturopathic physicians, pharmacognocists, pharmacists, midwives, plant chemists and medical herbalists and we encourage health professionals to obtain a more general education in the area before applying treatments to themselves or their patients. Bastyr University assumes no responsibility for the results obtained from using this information. If you have a serious or lingering health concern, it is important to discuss it with a health care provider.
