Echinacea: - Medical & Other Uses

Medical & Other Uses

From the Consumer Guide to Echinacea

Echinacea has become a best-selling herb because of its well-documented ability to boost immunity and its strong anecdotal reputation to short-circuit colds and the flu. Echinacea may also help fight bacterial and viral infections in the ears, vagina, urinary tract, and other sites, lower fever, and calm allergic reactions. Echinacea (pronounced eck-in-a-shuh) was a favorite herb of various Native American tribes, who used it to treat snakebites, insect bites, and wounds. Echinacea is a versatile and popular herb derived from the purple coneflower (Echinacea angustifolia, E. purpurea, E. pallida), a plant native to North America. The healing compounds are found in both the root and the aboveground parts of the herb.

Traditional uses

Echinacea (pronounced eck-in-a-shuh) was a favorite herb of various Native American tribes, who used it to treat snakebites, insect bites, and wounds. Its use in strongly alcoholic, over-hyped patent medicines of the late 1800's may have given rise to the pejorative term "snake oil" applied to quack cures. Modern research has demonstrated the herb offers real therapeutic benefits.

Modern research

Colds, Flu, and Respiratory infections: There is limited clinical evidence that sufficient oral doses of Echinacea can reduce the duration and severity of upper respiratory infections-colds, bronchitis, pneumonia, flu, etc. There is more evidence that injected doses of echinacea are an effective therapeutic agent against respiratory infections, especially in children. Results of two placebo-controlled, double blind German studies indicate that therapeutic doses of Echinacea purpurea may reduce the severity of colds, and that continuous use may reduce their frequency. patients with weakened immune response (CD4/CD8 ratio less than 1.5) received the most benefit. The dose was critical. Treatment with two droppersful (450 mg) of a crude alcohol extract (1:5 ratio of herb to alcohol) was ineffective, but treatment with 4 droppersful (900 mg) produced a statistically significant advantage over placebo. Several controlled clinical trials of European herb formulas featuring echinacea (i.e., Esberitox) have shown benefit in reducing the frequency, duration and severity of flu.
Candida (yeast) infections: Studies in mice and clinical trials in humans indicate that echinacea may be effective in suppressing yeast infections.
Skin/Wounds: Evidence to date indicates that echinacea is useful when applied externally to cuts, abrasions, bites, and stings to help promote healing, regenerate healthy cells, reduce inflammation, and maintain the structure of connective tissue. In an uncontrolled clinical study of 4,598 patients with various skin conditions, a topical E. purpurea ointment was found effective in treating 85.5% of patients with wounds, burns, eczema, inflammations, herpes simplex, and varicose ulcers.
General Immunity: The immune-stimulating effects of echinacea were first reported in 1914. By the 1930's German researchers had initiated studies (400-plus to date) exploring echinacea's immune effects. These include some clinical studies, but primarily research in animals and test tube cell cultures. A few tests on humans have shown echinacea to exhibit clinically significant activation of macrophage and granulocyte (immune cell) activity with an increase of phagocytosis (ingestion of microbes and foreign bodies by immune cells). Clinical evidence further indicates echinacea may help fight bacterial and viral infections in the ears, vagina, urinary tract , and other sites, lower fever, and calm allergic reactions.
Efficacy:One German study indicates that echinacea's immune-stimulating effects begin to subside after 5 days.

Recent findings

Echinacea was found to have no clear advantage over placebo in preventing upper respiratory tract infections, in a double-blind, placebo-controlled trial involved 289 volunteers. proportions of participants receiving echinacea who developed an infection were slightly lower than placebo, but this could have been due to chance. Two out of three other controlled trials produced similarly inconclusive results with regard to prevention.
Italian scientists found that echinacea has a number of polyphenol antioxidant compounds.
A review of five healthy-volunteer studies on the immune-boosting effects of echinacea suggested that the herb enhances the activity of immune cells known as phagocytes.
Extracts of Echinacea purpurea were found to enhance cellular immune function among both healthy subjects and those with chronic fatigue syndrome or acquired immunodeficiency syndrome.

Do scientists know how it works

Research has not clearly identified the herb's primary immune-stimulating constituents. Echinacea contains polysaccharides such as inulin and other compounds known to activate white blood cells and boost the immune system (e.g., fucogalactoxyloglucans, arabinogalactan). Echinacea increases levels of the antiviral substance interferon (an important part of the body's response to viral infections such as colds and the flu) as well as an immune-related blood protein known as properdin. Echinacea also prompts the thymus, bone marrow, and spleen to develop more immune cells. Other immunity-stimulating compounds include aliphatic amides; isobutylamides of polyenyne, polyine, and polyene acids; phenols, including mono- and dicaffeate of tartaric acid (cichoric acid, etc.), volatile oil, and derivatives of caffeic acid (dicaffeoylquinic acids, cynarin, echinacoside, chlorogenic acid). Echanoside possesses bacterio- and fungistatic properties.

Safety

One of the least toxic herbs, echinacea is not known to cause any side effects when taken orally. Allergic reactions are rare but can be life threatening, causing anaphylactic shock. You may want to try a very small dose at first if you're allergic to other plants in the ragweed family. As a general immune stimulant, most herbalists recommend that you stop taking echinacea for a week after six or eight weeks of continuous use. If you have an autoimmune illness, such as lupus, or other progressive disease such as multiple sclerosis, consult with a physician before taking echinacea. There are no known contraindications to the use of echinacea during pregnancy or breastfeeding.

Types of products

Herbal companies offer echinacea in a wide variety of dry and liquid forms, including freeze-dried, tablets, capsules, fresh juice, concentrated drops, tinctures, teas, ointments, and gels. Echinacea extracts may be standardized for low percentages of compounds such as echinacoside. Echinacea is often combined with goldenseal, elderberry, vitamin C, zinc, propolis, and other natural substances. Many herbalists and users believe that the potency of a liquid echinacea extract is revealed by the strength of the tingling sensation produced on the tongue by its isobutylamides-and the stronger the better.

References

Braunig B et al. Echinacea: Clinical trial re: rhinovirus. Zeitschrift fur phytotherapie 13;7 1992.
Coeugniet E, Kuhnast R. Echinacea: Clinical trial re: Candiasis. Therapiewoche 36:3352, 1986.
Facino, R.M., et al. Echinacoside and caffeoyl conjugates protect collagen from free radical-induced degradation: A potential use of Echinacea extracts in the prevention of skin photodamage. planta Medica 1995, 61:51014.
Jurcic K et al. Echinacea: duration of effect Zeitschrift fur phytotherapie 10; 67-70, 1989.
Melchart D, et al. Echinacea: Clinical trial re: rhinovirus. Archives of Family Medicine, November-December 1998.
Melchart D, et al. Results of five randomized studies on the immunomodulatory activity of preparations of Echinacea, J Altern Complement Med (1995), 1(2):145-60.
Mengs U, Clare CB, poiley JA. Toxicity of Echinacea purpurea. Acute, subacute and genotoxicity studies. Arzneimittelforschung 1991 Oct;41(10):1076-81.
Roesler J, et al. Application of purified polysaccharides from cell cultures of the plant Echinacea purpurea to test subjects mediates activation of the phagocyte system. Int J Immunopharmacol 1991;13(7):931-41.
See, D.M., et al. In vitro effects of Echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiency syndrome patients. Immunopharmacology (1997), 35(3):229- 35.
Schoneberger D. Echinacea: Clinical trial against rhinovirus. Forum Immunologie, 8:2-12, 1992.
Steinmuller C et al. polysaccharides isolated from plant cell cultures of Echinacea purpurea enhance the resistance of immunosuppressed mice against systemic infections with Candida albicans and Listeria monocytogenes. Int J Immunopharmacol 1993 Jul;15(5):605-14.
Veihmann p. Echinacea: Uncontrolled clinical trial re: skin conditions. Erfahrungsheil, 27:353, 1978