Echinacea is a plant that bears single pink or purple flowers from its tall stems, with a central cone that often appears purplish-brown in color. This accounts for its alternate name in some cultures, the “Purple Cone Flower”. Although there are several species of the echinacea plant, only 3 are used for medicinal purposes (Echinacea augustifolia, Echinacea pallida, and Echinacea purpurea) (6).
Echinacea is used for a range of benefits, including as an antiviral, an immune stimulant, and to relieve urinary tract infections and yeast-related disorders. Extracts from Echinacea purpurea add to the body’s resistance to bacterial and viral infection (3) (9) and have shown indirect antiviral activity (4).
The success of echinacea as a supportive therapy for colds and other respiratory infections is well documented (1) (5) (8) (11). This comes as no surprise, as echinacea is an immune stimulant, a fact established by numerous scientific studies (2) (4) (7) (8). Some effects of echinacea include an increase of the number of white blood cells and spleen cells, elevations in body temperature and reproduction of T-helper cells (5).
Historically echinacea has been taken for septicemia, migraines, streptococcus infections, syphilis, typhoid, malaria and diphtheria. Often echinacea is included with in combination with other herbs to treat or prevent colds and other upper respiratory infections (2) (3).
Echinacea arrives to us from the tribal medicine of the North American Indians, and by the 19th Century had become the most widely used plant drug in the United States (13). It was used in various forms for many ailments throughout the Americas, including as an aphrodisiac, to relieve headache and stomach pains, improve appetite and ease nausea and fevers. Echinacea root was chewed to treat colds and sore throats (23). It is further listed as an antibacterial, candidicide and trichomonicide in James Duke’s Handbook of Medicinal Herbs (36).
A double-blind, placebo-controlled study indicated that 450 mg/day of Echinacea purpurea root extract significantly relieved the severity and duration of flu symptoms (4).
A total of 26 controlled clinical trials in Germany were conducted on the immunomodulatory activity of echinacea preparations prior to 1994. After reviewing the 34 test treatment groups, 22 were considered to have given results indicating echinacea’s positive effects on the immune system, particularly with regard to upper respiratory infections (9).
Lab studies in mice have shown that arabino-galactins from Echinacea purpurea provide protection against certain test microorganisms. The test results showed a 100% preventative effect against lethal Candida albicans infections and “very good preventative effect” against lethal Listeria and Leishmania infections (10). Both in vivo and in vitro immunostimulant activity in mice has been documented for echinacea (12).
Echinacea is considered generally safe when taken orally for periods of no longer than 8 consecutive weeks of daily use. Due to the insufficient reliable evidence on the use of echinacea while pregnant or breastfeeding it cannot be recommended for use during these times.
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- “Echinacea” Complementary Medicine Library. IVillage.com (Accessed May 22, 2003). http://www.ivillagehealth.com/library/onemed/content/0,,241012_246607,00.html
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