Medicinal Plants
Medicinal Plants
Ever experienced the runny nose, itchy eyes or skin rash that are results of an allergic reaction? Perhaps around certain times of year you leave your house only to be bombarded with pollen and spores that set off your seasonal allergies. Maybe you have experienced the itchy red rash that appears after a dog has licked your arm and your perennial allergies have been set off. With so many prescriptions and over the counter allergy options you would think that you wouldn’t have to suffer from allergens. However, all of these treatments are only temporary, because there is no cure for allergies. Fifty million Americans suffer from allergy symptoms, quite a market for the pharmaceutical industry. Aside from the multitude of allergy relief options found in your local supermarket or drugstore there are natural products that can also help relive some allergy symptoms.
The stinging nettle (Urtica dioica) has been used since ancient times to relieve allergy symptoms. The plant is a common weed found all over the United States and the Northern Hemisphere. The plant has been used for many medical ailments such as allergies, pain and urinary tract infections, among others. Above ground portions of the plant can be used to treat seasonal and year round allergies. Stems and leaves can be freeze dried to preserve chemical components of the plant and then taken orally to relieve allergy symptoms.
The stinging hairs on the nettle contain serotonin, acetylcholine and histamine. Following contact with the stinging hairs there is an immediate stinging and burning sensation. These sensations are followed by a hyperemic rash at the affected area. When the nettle comes in contact with the skin it breaks off from the stem of the plant and its contents are released into the body. By this mechanism the histamine, serotonin and acetylcholine are released into the body.
It seems contradictory that histamine from the stinging nettle would alleviate allergy symptoms, however its action is able to reduce the amount of histamine produced in the body. The mechanism of nettle as an anti-inflammatory agent is unclear; however, the answer is related to the nettle’s histamine content. “Histamine down regulates the function of human polymorphonuclear and reduces biosynthesis of leukocytes (PMNs)89 leukotriene B4 (LTB4) by inhibiting at least three of its induction pathways. LTB4 increases edema and chemotaxis, induces release of lysosomal enzymes, increases reactive oxygen species, and enhances production of the cytokines TNF-α, IL-1, and IL-6.”2
The stinging nettle has multiple side effects when taken for allergies. These side effects include mild stomach upset, fluid retention, sweating, diarrhea, and hives or rash (when applied topically). The nettle can also alter a women’s menstrual cycle so women should be careful taking it to avoid alteration of menstrual cycle, miscarriage or unexpected pregnancy.
A dose of 300 mg/day of freeze-dried Urtica dioica is recommended for the treatment of allergic rhinitis. Of sixty nine patients who used stinging nettle in a double blind study 58% said that it was effective in relieving their allergy symptoms. As always it is important to take precautions when using medication not prescribed by a doctor and to be aware of the possible side effects. But for those people who suffer from allergies the stinging nettle could be a way to naturally alleviate symptoms.
1. Cummings, A. J., and Olsen, M. (2011) Mechanism of Action of Stinging Nettles. Wilderness and Enviornmental medicine 22, 136-139.
2. Helms, S., and Miller, A. (2006) Natural treatment of chronic rhinosinusitis, Alternative medicine review : a journal of clinical therapeutic 11, 196-207.
3. Thornhill, S. M., and Kelly, A.-marie. (2000) Natural Treatment of Perennial Allergic Rhinitis, Alternative Medicine Review 5, 448-454.
The stinging nettle only
Will still be found to stand:
The numberless, the lonely,
The thronger of the land,
The leaf that hurts the hand.
That thrives, come sun, come showers;
Blow east, blow west, it springs;
It peoples towns, and towers
Above the courts of Kings,
And touch it and it stings.
-A.E. Housman
Friday, April 27, 2012
Stinging Nettles - Julie Swinson