Nettle

Botanical Name(s):

Urtica dioica L. Family: Urticaceae

Other Name(s):

common nettle, greater nettle, stinging nettle

General Description:

The stinging nettle is a noxious plant with tiny stinging hairs covering its surface. Contact with the plant produces a stinging or burning sensation in the skin and a wheal and flare at the site of contact. This reaction is thought to be produced by histamine from the plant that is released as the hairs pierce the skin.

There are several species of stinging nettle, including Urtica dioica, Urtica urens and Urtica pilulifera. Nettle grows wild in temperate regions and can reach 2 to 3 feet in height. Nettle has a long reputation in folk medicine as a treatment for asthma and as an expectorant, astringent, tonic, anti-spasmodic and diuretic.

Medically Valid Uses:

The best established uses for nettle (in conjunction with other agents) include treatment of arthritis and benign prostatic hypertrophy (BPH). Nettle extract may influence BPH by binding to sites on sex hormone binding globulin (SHBG) and, subsequently, decreasing testosterone's effect on the prostate.

Unsubstantiated Claims:

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Nettle extract has components that interfere with inflammation. Inflammation plays an important role in the pain and joint damage associated with arthritis . However, there is little hard evidence to support the efficacy of this herb for this condition. Further scientific studies are needed to verify nettle's efficacy.

Other common, but equally unsupported, claims include nettle's efficacy as a diuretic and in treating rheumatism.

There are claims that nettle may also be used in the management of asthma, gout, hay fever, high blood pressure, irritable bladder, nosebleeds, PMS, scurvy and stings/venomous bites. In addition, nettle is claimed to possibly increase milk production in breast-feeding women, and to stimulate hair growth. Nettle has also been used as an expectorant, astringent, and hair and scalp remedy (for oily hair and dandruff).

Dosing Format:

Nettle is available as a juice or herb that may be mixed into a tea. The average dose is 8 to 12 grams/day, which should be taken with at least 2 liters of liquid each day.

Side Effects, Toxicity and Interactions:

With proper use of this herb, there are no health hazards. Possible allergic reactions (skin conditions, erythema or edema) rarely occur. Nettle may also cause stomach cramps or diarrhea; if so, discontinue use of the herb or decrease the amount taken.

Do not use this herb if you have fluid retention that is a result of cardiac or renal dysfunction.

Women who are pregnant or breast-feeding should also not take this herb due to its potential diuretic effect.

Diuretics may lead to potassium loss. However, because the effect of this herb is mild compared with modern diuretics, potassium deficiency is unlikely.

Additional Information:

Click here for a list of reputable Web sites with general information on nutrition.

References:

1. Gruenwald J, Brendler T, Jaenicke C, eds. PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company; 1998.

2. Tyler V. The Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. New York, NY: Haworth Press, Inc.; 1993.

3. Miller LG, Murray WJ. Herbal Medicinals. Binghamton, NY: Pharmaceutical Products Press, Haworth Press Inc.; 1998:215-217.

4. Galelli A, Delcourt M, Wagner MC, et al. Selective expansion followed by profound deletion of mature V beta 8.3+ T cells in vivo after exposure to the superantigenic lectin Urtica dioica agglutinin. J Immunol. 1995;154(6):2600-11.

5. Krzeski T, Kazon M, Borkowski A, et al. Combined extracts of Urtica dioica and Pygeum africanum in the treatment of benign prostatic hyperplasia: double-blind comparison of two doses. Clin Ther. 1993;15(6):1011-20.

6. Pusztai A, Ewen SWB, Grant G, et al. Antinutritive effects of wheat-germ agglutinin and other N-acetylglucosamine-specific lectins. Br J Nutr. 1993;70(1):313-21.

7. Castleman M. The Healing Herbs: The Ultimate Guide to the Curative Power of Nature's Medicines. New York, NY: Bantam Books; 1995:393-398.

8. Oliver F, Amon EU, Breathnach A, et al. Contact urticaria due to the common stinging nettle (Urtica dioica)-- histological, ultrastructural and pharmacological studies. Clin Exp Dermatol. 1991;16(1):1-7.

9. Galelli A, Truffa-Bachi P. Urtica dioica agglutinin. A superantigenic lectin from stinging nettle rhizome. J Immunol. 1993;151(4):1821-31.

10. Dreikorn K, Schonhofer PS. [Status of phytotherapeutic drugs in treatment of benign prostatic hyperplasia]. Urologe A. 1995;34(2):119-29.

11. Schottner M, Gansser D, Spiteller G. Lignans from the roots of Urtica dioica and their metabolites bind to human sex hormone binding globulin (SHBG). Planta Med. 1997;63(6):529-32.

12. Riehemann K, Behnke B, Schulze-Osthoff K. Plant extracts from stinging nettle (Urtica dioica), an antirheumatic remedy, inhibit the proinflammatory transcription factor NF-kappaB. FEBS Lett. 1999;442(1):89-94.

13. Rovira P, Buckle M, Abastado JP, Peumans WJ, Truffa-Bachi P. Major histocompatibility class I molecules present Urtica dioica agglutinin, a superantigen of vegetal origin, to T lymphocytes. Eur J Immunol. 1999;29(5):1571-80.