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Echinacea

(E. purpurea, E. pallida, E. angustifolia)

Family: Compositae, Asteraceae

Synonyms: Purple coneflower, Pale purple coneflower, Narrow-leaf purple coneflower, Kansas niggerhead, Sampson root (1), American coneflower, Black Sampson, Black Susans, Brauneria angustifolia or pallida, Comb flower, Hedgehog, Igelkopfwurzel, Indian Head, Kansas snakeroot, Purpursonnenhutkraut, Purpursonnenhutwurzel, Racine dŽchinacea, Red sunflower, Rock-up-hat, Roter sonnenhut, Schmallblaettrige, Kegelblumenwurzel, Schmalltrigger sonnenhut, Scurvy root, Snakeroot, Sonnenhutwurzel (2).

Downloadable PDF of this monograph

Plant characteristics

 
The Echinaceas include nine species, three of which have been studied for their medicinal properties: E. Purpurea (Purple coneflower), E. angustifolia (Narrow-leafed coneflower), and E. pallida (Pale coneflower). All are herbaceous perennials native to the North American prairies and open woodlands (3). E. angustifolia grows to about 20 inches in height. It has a bristly disk surrounded by pale pink drooping rays and a soft tap root. E. pallida grows a little taller, though is very similar in appearance to E. angustifolia and the two species are often confused with one another. In both plants, the leaves are lance-shaped and narrow. E. purpurea has broader, toothed leaves, deeper pink petals, and characteristic orange-tipped spines in the flower disk (3). Its root is fibrous (4).

E. purpurea grows vigorously in North Carolina and is a common garden perennial. Gardeners have not cultivated E. pallida and E. angustifolia as widely. Hence, their seed characteristics resemble those of wild plant species ( e.g. the seeds require scarification and soaking) (4). Growers can propagate Echinacea from seed or division and plant the seedlings in spring or early summer (5). Echinaceas flower from June to October. Growers harvest the flower heads and leaves at the bud stage and the roots during the fall of the second or third year (5). The seeds of 2 or 3 year old plants are valuable as well.

Herb medicinal and properties

Biologically-active chemicals: water-soluble polysaccharides, caffeic and ferulic acid derivatives, glycoproteins, and fat-soluble alkylamides along with volatile oils, flavanoids, and trace amounts of 1,2 saturated pyrrolizidine alkaloids (not the unsaturated alkaloids implicated in hepatotoxicity) (6-9). The constituents vary between species, by part of the plant examined (i.e., above ground plant vs. root), and by growing conditions, time of harvest, etc (10).

Herbal properties: Alterative, analgesic, antiedemic, antiexudative, anti-inflammatory, antispasmodic, antiseptic, antiviral, fungicidal, immunostimulant, protisticidal, sialogogue, trichomonicidal, vasodilator, vulnerary (11).

How herb was used traditionally

The Lakota people called E. angustifolia Icahpe hu and used it for snake bites, sepsis, and rabies (9,12). The Blackfoot saw the plant as a remedy for toothache and other tribes used it for cough medicine (Choctaw), venereal disease (Delaware), sore throats (Comanche), rheumatism and colds (Cheyenne), and eye infections (Dakota) (13). Among the early European settlers, Echinacea purpurea first appeared in John Clayton's 1762 Flora Virginica as a remedy for saddle sores on horses (13).

Echinacea became a favorite of the Eclectic physicians in the U.S. when H.C.F. Meyer produced a commercial medicine from E. angustifolia (14,15). After investigating Dr. Meyer's claims about the plant, Dr. John King and John Uri Lloyd determined that it had significant value and created an Echinacea Specific Medicine for sepsis, cancerous growths, typhoid, puerperal fever, throat infections, wound healing, and inflammatory skin conditions (8,13,16). In Ellingwood's American Materia Medica, Echinacea is listed as a treatment for syphilis, typhus, diphtheria, chronic mastitis, and tuberculosis as well (17).

Echinacea preparations fell out of favor in the U.S. with advances in antibiotics and the decline of the Eclectics (18), though both E. angustifolia and E. pallida remained in the National Formulary though its 1947 edition (13). Gerhard Madaus, a German pharmaceutical manufacturer imported E. purpurea seeds to Germany in the 1930s. Since then, German scientists have conducted research into the biochemistry, pharmacology, and clinical usefulness of the herb (19).

Echinacea is the most commonly used herbal product in the U.S.: 40.3% of adults surveyed in 2002 reported that they had taken the herb over the past 12 months (20). The herb continues to enjoy popularity in Europe as well, especially in Germany where over 200 Echinacea products are available (21). Retailers sold $58 million worth of Echinacea products in 2000 (8). Manufacturers market Echinacea as an immune stimulant and the public uses it most often to treat cold symptoms (22-26).

Modern herbalists continue to value Echinacea for treatment of a variety of infectious conditions, such as upper respiratory infections, urinary tract infections, otitis media, vaginal candidiasis, and skin infections (9,15,17,27). Echinacea is often combined with herbs with antimicrobial activity, such as Goldenseal or other berberine containing herbs (9). Because of its anti-inflammatory properties, Echinacea is also helpful as part of a formula to treat acute arthritic conditions (9,15).

Preparation and Dosage: Many preparations of Echinacea are available commercially in a variety of forms, including tea bags, capsules, alcoholic tinctures and fluid extracts, and non-alcoholic liquid formulations that are stabilized in glycerin or concentrating in a liquid filled capsule. The products contain various species and plant parts and cannot be considered as equivalent. Clinical trials have employed different formulations as well. At his time, the gaps in scientific knowledge regarding the optimal concentrations of the constituents and their bioavailability in different forms make a definitive recommendation of a specific product impossible. Some scientists recommend the use of a liquid form or buccal tablet of Echinacea, because of its possible capacity to stimulate tonsillar lymphoid tissue (14).

Regardless of the form, most herbalists suggest very frequent dosing of Echinacea at the time the first symptoms appear in the case of acute infections, i.e., every 2-3 hours while awake (9,15), and followed by tapering dosage schedules as the symptoms abate.

• Take one dropperful (40 drops) of a 1:3-1:5 tincture in 30-45% EtOH containing E. purpurea herb and root, with perhaps the addition of E. angustifolia root.

• The tea is prepared by steeping one tea bag in a cup of water for 15 minutes or simmering 1 tsp of root for 15 minutes and drinking one cup every 2-3 hours.

The German Commission E recommends the following for chronic conditions:

• E. purpurea fresh pressed juice, total of 6-9 ml/ day

• E. angustifolia root, total of 2-6 ml of 1:2 fluid extract or 5-15 ml of the 1:5 tincture

• E. purpurea root, 1:2 fluid extract, 3-9 ml/day or 7.5-22.5 ml of the 1:5 tincture

Dosage may be increased for acute infections.

Patients may note a tingling, numbing sensation on the tongue when taking the tincture.

How herb is used today (based on scientific evidence)

European and American researchers have conducted hundreds of studies on Echinacea and its constituents. Studies include a large number of clinical trials. Unfortunately, conclusions are not easy to draw from the available information due to:

(1) methodological flaws in the trials
(2) varying plant species and plant parts, making preparations lack equivalency (21)
(3) varying dosing schedules (28)
(4) addition of other herbal components
(5) failure of the study investigators to assay product for constituents
(6) lack of comparability of measured outcomes (29)

Up until the past 10 years, most of the research on Echinacea was conducted in Germany, primarily using E. purpurea (29).

Echinacea is possibly effective for:

Treating the common cold. Patients who take Echinacea for a cold seem to feel better, though they do not necessarily have fewer symptoms. See comments above regarding difficulties in interpretation of the clinical trials- several have revealed a 10-40% reduction in symptoms, though a few trials have negative results (29).

It is unclear if Echinacea is effective for:

• Preventing the common cold. Some studies have been positive and others have been negative (21,30-32)
• Treating wound infections. A small study was positive, but the verdict is still out (33).
• Prevention of vaginal yeast infection- one positive study using Echinacin has been conducted (8).
• Prevention of secondary outbreaks of genital herpes- the only known study was negative study (using Echinaforce) (34).

Safety issues

Side effects: unpleasant taste (1.7%); nausea/vomiting (0.48%); abdominal pain, diarrhea, sore throat (0.24%) (18). Heartburn, upset stomach, fatigue, sleeplessness, dizziness, headache, aggressive behavior, eczema, nonspecific rash, itchiness, increased hair loss, increased urge to urinate are reported in clinical trials, though Echinacea was well-tolerated in general (28,32,35,36).

Adverse events: Echinacea has rarely been associated with rash, asthma, and anaphylaxis in sensitive individuals (35,37,38). Other allergic reactions include hives, itchy eyes, runny nose, chest tightness, shortness of breath, and croup (2).

In Germany, 3 patients (over a 6 year period) who took Echinacea have died, one of inflammation of the blood vessels and another of low platelet count. It is unclear if Echinacea caused these problems (39).

Precautions/contraindications:

• Safety of Echinacea in pregnancy is uncertain (29), but studies to date reveal no evidence for frequent adverse outcomes (40)

• Avoid with tuberculosis, HIV infection, progressive diseases such as lupus, multiple sclerosis.

  Avoid Echinacea with an allergy to ragweed, chamomile, and other members of the daisy family

References

1.               Lust J: The Herb Book. New York, Bantam Books, 1974.

2.               Jellin JM, Gregory PJ, Batz F, et al: Pharmacist's Letter/ Prescriber's Letter Natural Medicines Comprehensive Database, vol 2004. Stockton, CA, Therapeutic Research Faculty, 2004.

3.               Foster S, Duke J: A Field guide to Medicinal Plants and Herbs of Eastern and Central North America. New York, Houghton Mifflin, 2000.

4.               Wang X, Scalzo R, Chen Y, et al: Echinacea Research Progress Report, in Medicines from the Earth: The Twelfth Annual Symposium on Botanical Medicine. Black Mountain, NC, Gaia Herbal Research Institute, 2004.

5.               Sturdivant L, Blakeley T: The Bootstrap Guide to Medicinal Herbs in the Garden, Field, & Marketplace. Friday Harbor, WA, San Juan Naturals, 1999.

6.               Blumenthal M: Herbal Medicine: Expanded Commission E Monographs, 1st ed. Newton, MA, Integrative Medicine Communications, 2000.

7.               WHO: Herba Echinaceae Purpureae, in WHO monographs on selected medicinal plants, vol 1. Geneva, World Health Organization, 1999.

8.               Blumenthal M, Hall T, Goldberg A, et al: The ABC Clinical Guide to Herbs. Austin, Texas, American Botanical Council, 2003.

9.               Low Dog T: Foundations of Herbal Medicine. Albuquerque, 2000.

10.             Percival SS: Use of echinacea in medicine. Biochem Pharmacol 60(2):155-8, 2000.

11.             Duke JA: Handbook of Medicinal Herbs. Boca Raton, CRC Press, 1985.

12.             Hutchens AR: Indian Herbology of North America. Boston, Shambhala Publications, Inc., 1991.

13.             Flannery MA: From rudbeckia to echinacea: the emergence of the purple cone flower in modern therapeutics. Pharm Hist 41(2):52-9, 1999.

14.             Schulz VPDm, Hþnsel R, Blumenthal M: Rational Phytotherapy, 5th ed. Berlin ; New York, Springer, 2001.

15.             Tierra M: The Way of Herbs. New York, Pocket Books, 1998.

16.             Foster S, Tyler VE: Tyler's Honest Herbal: A sensible guide to the use of herbs and related remedies. Binghamton, NY, The Haworth Herbal Press, 1999.

17.             Mills S, Bone K: Principles and Practice of Phytotherapy. Philadelphia, Churchill Livingstone, 2000.

18.             Echinacea, in The Review of Natural Products. Edited by DerMarderosian A, Beutler JA. St. Louis, Missouri, Facts and Comparisons, 2000.

19.             Blumenthal M, Busse WR: The complete German Commission E monographs, Therapeutic guide to herbal medicines. Austin, Texas American Botanical Council, Boston, 1998.

20.            Barnes PM, Powell-Griner E, McFann K, et al: Complementary and Alternative Medicine Use among Adults : United States, 2002. Atlanta, Centers for Disease Control and Prevention, National Center for Health Statistics, 2004.

21.             Melchart D, Linde K, Fischer P, et al: Echinacea for preventing and treating the common cold (Cochrane Review), in The Cochrane Library. Chichester, U.K., John Wiley & Sons, Ltd., 2004.

22.            Stewart R: Cold and Flu Fighters Echinacea and Larch Tree Extract., in Alive: Canadian Journal of Health & Nutrition, Canadian Health Reform Products Ltd., 2002.

23.            Anonymous: Cold, flu sufferers embrace herbals. Chain Drug Review 19(17), 1997.

24.            Barrett B, Vohmann M, Calabrese C: Echinacea for upper respiratory infection. J Fam Pract 48(8):628-35, 1999.

25.            Mark JD, Grant KL, Barton LL: The Use of Dietary Supplements in Pediatrics: A Study of Echinacea. Clinical Pediatrics 40(5):265-269, 2001.

26.            Giles JT, Palat CT, 3rd, Chien SH, et al: Evaluation of echinacea for treatment of the common cold. Pharmacotherapy 20(6):690-7, 2000.

27.            Hoffman D: Medical Herbalism. Rochester, Vermont, Healing Arts Press, 2003.

28.            Goel V, Lovlin R, Barton R, et al: Efficacy of a standardized echinacea preparation (Echinilin) for the treatment of the common cold: a randomized, double-blind, placebo-controlled trial. J Clin Pharm Ther 29(1):75-83, 2004.

29.            Barrett B: Medicinal properties of Echinacea: a critical review. Phytomedicine 10(1):66-86, 2003.

30.            Cohen HA, Varsano I, Kahan E, et al: Effectiveness of an herbal preparation containing echinacea, propolis, and vitamin C in preventing respiratory tract infections in children: a randomized, double-blind, placebo-controlled, multicenter study. Arch Pediatr Adolesc Med 158(3):217-21, 2004.

31.             Melchart D, Walther E, Linde K, et al: Echinacea root extracts for the prevention of upper respiratory tract infections: a double-blind, placebo-controlled randomized trial. Arch Fam Med 7(6):541-5, 1998.

32.            Grimm W, Muller HH: A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med 106(2):138-43, 1999.

33.            Potii VV: [Applications of immunomodulators in complex of treatment of the soft tissue purulent wounds]. Klin Khir (10):15-6, 2000.

34.            Vonau B, Chard S, Mandalia S, et al: Does the extract of the plant Echinacea purpurea influence the clinical course of recurrent genital herpes? Int J STD AIDS 12(3):154-8, 2001.

35.            Taylor JA, Weber W, Standish L, et al: Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. Jama 290(21):2824-30, 2003.

36.            Barrett BP, Brown RL, Locken K, et al: Treatment of the common cold with unrefined echinacea. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 137(12):939-46, 2002.

37.            Mullins RJ: Echinacea-associated anaphylaxis. Med J Aust 168(4):170-1, 1998.

38.            Mullins RJ, Heddle R: Adverse reactions associated with echinacea: the Australian experience. Ann Allergy Asthma Immunol 88(1):42-51, 2002.

39.            Bone K: Echinacea: when should it be used?... second in a two-part series. Alternative Medicine Review 2(6):451-458, 1997.

40.            Gallo M, Sarkar M, Au W, et al: Pregnancy outcome following gestational exposure to echinacea: a prospective controlled study. Arch Intern Med 160(20):3141-3, 2000.

41.             Davis J, Greenfield J: Results from Strategic Reports' Analysis of the economic viability of cultivating selected botanicals in North Carolina, 2001 statistics. Raleigh, NC, North Carolina State University, 2003.

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