Volume 6-4

Monograph
Echinacea
Introduction
the Compositae family; the three species ofmedicinal interest being Echinaceaangustifolia, Echinacea purpurea, and Echinacea pallida. Echinacea angustifolia has been used therapeutically for centuries by Native Ameri-cans as a remedy for eye conditions, snake bites, insect stings, infected wounds, eczema, enlargedglands, mumps, and rabies. It was also used as a painkiller for a variety of conditions from stomach-aches to epilepsy. In the early 20th century, Echinacea was used by a group of physicians known as the“Eclectics,” whose medicinal practice relied primarily on the use of plants and their disease-healingproperties. During the Eclectic era, Echinacea was used to treat a variety of kidney and urinary tractconditions, chronic bacterial infections, and syphilis.1 From the 1930s-1970s, antibiotic developmentresulted in a sharp decline in Echinacea use, but due to a subsequent disenchantment with the medicalestablishment, an herbal medicine “renaissance” in the 1980s led to renewed interest in Echinacea’sbenefits. Echinacea research during the last 20 years has focused on its immune-stimulating properties.
Currently, Echinacea is being used to combat bacterial, viral, protozoan, and fungal infections, as ananti-inflammatory agent, and as a possible chemopreventative agent.
Description and Constituents
Echinacea is also known as purple coneflower, red sunflower, thimbleweed, and Rudbeckia. It is native to much of the United States, with locations varying by species, and is usually found in openmeadows or damp locations such as woods, swamps, ditches, river banks, and low-lying thickets. It hasa thick, black, pungent root, narrow leaves, and a stem growing to a height of three feet.2 The floweringhead is orange and cone-shaped, bearing purple, rose, or white petals from June to September.3 Active constituents vary slightly according to species and include caffeic acid derivatives (pri- marily echinocoside), flavonoids, essential oils, polyacetylenes, alkylamides, and polysaccharides. Nosingle constituent has been found to be primarily responsible for Echinacea’s immune-stimulatingeffect; rather they appear to all work together to accomplish this. Therefore, extracts standardized to aspecific echinocoside concentration may not be the most beneficial, as this standardization may be atthe expense of the other active constituents.2 Alternative Medicine Review ◆ Volume 6, Number 4 ◆ 2001 Page 411
Copyright2001 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission Myths About Echinacea
Misinterpretation of the scientific literature regarding Echinacea’s effect on the immune system has led to the development of several myths regarding Echinacea’s therapeutic use including: (1)Echinacea is only appropriate for short-term use because it is not desirable to stimulate the immunesystem continuously,4 and (2) Echinacea is an immune stimulator and as such, its use may be contrain-dicated in “progressive conditions” such as tuberculosis, leukemia, allergies, collagen disorders, mul-tiple sclerosis, HIV/AIDS, and autoimmune disease.5 However, the Native Americans’ and Eclectics’high-quality, traditional-use data is a result of decades of extensive clinical experience, and does notsupport the suggested limitations. King2 and Ellingwood6 recommended long-term use of Echinaceafor a variety of chronic conditions, including tuberculosis and autoimmune-related disorders. Simi-larly, neither modern research data nor authoritative herbal reference sources support the suggestedlimitations on Echinacea use. Numerous clinical studies of Echinacea have been conducted over thelast 20-30 years that overwhelmingly demonstrate its therapeutic benefit and safety, even in patientswith autoimmune disorders.7,8 The British Herbal Pharmacopoeia,9 The British Herbal Compendium,10and The Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics11 list nocontraindications for Echinacea. Weiss also suggests Echinacea has an excellent safety profile and noside effects.12 Echinacea and Immune Stimulation
Echinacea’s immune-stimulating properties are quite complex and are attributed to the com- bined effect of several of its constituents.13 The Eclectic physicians discovered alcohol extracts ofEchinacea directly stimulated white blood cell production and phagocytic activity.6 Modern clinicaland in vitro research has confirmed the Eclectics’ observations regarding increased phagocytosis,14 NKcell activity, and increased antibody-dependent cellular cytotoxicity, mediated by tumor necrosis fac-tor-alpha (TNF-α). The latter study was conducted using peripheral blood mononuclear cells fromnormal individuals and patients with either chronic fatigue syndrome or AIDS.15 Due to its potential tostimulate TNF-α and interleukins 1 and 6, it has been suggested that Echinacea should not be used byAIDS patients as it may speed the course of the disease, although is not a universally held theory.3,4 Echinacea angustifolia also appears to have a mild antibiotic effect, probably attributable to its caffeic acid constituent, which is capable of directly inhibiting Staphylococcus aureus. In addition,certain polyacetylene constituents of Echinacea have been found to be bacteriostatic against E.coli andPseudomonas aeruginosa.13 E. angustifolia was also used by the Eclectics to treat fungal and proto-zoan infections, most notably malaria and Trichomonas vaginalis,13 although current research in thisarea is lacking.
Echinacea research during the past few years has primarily focused on its therapeutic benefit in treating symptoms of the common cold. A review of several clinical studies, comprised of over 3900patients, demonstrates that Echinacea extracts decrease the frequency, symptoms, and severity of thecommon cold.16-19 However, other similar studies (although fewer in number) have demonstratedEchinacea use to be of no significant benefit in lessening cold and flu symptoms.20,21 Echinacea and Inflammation
Native American and Eclectic uses of Echinacea as an anti-inflammatory agent were centered around poisonous snake bites and insect stings. Caffeic acid derivatives, high molecular weight polysac-charides, flavonoids, and essential oils found in Echinacea all possess anti-inflammatory properties.13Although current research on Echinacea’s anti-inflammatory effect is minimal, animal studies using E. Page 412 Alternative Medicine Review ◆ Volume 6, Number 4 ◆ 2001
Copyright2001 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission angustifolia have indicated the polysaccharide constituents of the extracts possess significant anti-inflammatory activity in attenuating paw and ear edema when applied topically to the skin of mice andrats.22-24 Echinacea and Cancer
Research on Echinacea’s benefit in cancer therapy is minimal and inconclusive, but because of its immune-stimulating properties, it may prove to be a useful adjunct to conventional cancer therapies.
An animal study demonstrated Echinacea’s ability to enhance cellular immunity in leukemic mice,resulting in a suppressive effect on leukemia, via increased production of endogenous interferon-gamma.25In another animal study, peritoneal macrophages from immunosuppressed mice incubated with Echinaceapolysaccharides showed increased production of TNF-α and enhanced macrophage activation. Themice in this study also exhibited restored resistance to Listeria monocytogenes and Candida albicans,lethal infections associated with their immunosuppressed state.26 Side Effects, Contraindications, and Herb/Drug Interactions
Historical use, modern research, and herbal reference publications show Echinacea to have an excellent safety profile. However, because it is an immune stimulant, caution should be used in com-bining it with immunosuppressive drugs such as corticosteroids, cyclosporine, amiodarone, methotrex-ate, and ketoconazole.27 Echinacea use has been reported to occasionally cause reversible skin reac-tions, and for this reason, it should be used with caution in atopic individuals.28 Echinacea is available in several forms, and dosages vary accordingly. Typical dosages for the Dried root = 0.5 to 1.0 grams three times dailyTincture (1:5) = 1/2 to 1 teaspoon three times dailyDry, powdered extract (standardized to 3.5% echinacoside) = 300 mg three times dailyLiquid Extract (1:1) = 1/4 to 1/2 teaspoon three times dailyFreeze Dried = 1 to 2 capsules or tablets three times daily References
1.
Wagner H. Herbal immunostimulants. Z Phytother 1996;17:79-95.
King J. The American Eclectic Dispensatory. Cincinnati, OH: Moore, Wistach, and Keys;1854.
Bergner P. The Healing Power of Echinacea and Goldenseal, and Other Immune System Herbs. Rocklin, CA:Prima Publishing; 1997.
Bone K. Echinacea: When should it be used? Altern Med Rev 1997;2:451-458.
Bisset NG. Herbal Drugs and Phytopharmaceuticals. Wichtl M Ed., (German edition). Stuttgart/Boca Raton:Medpharm Scientific Publishers/CRC Press; 1994:182-184. Ellingwood F. American Materia Medica, Therapeutics and Pharmacognosy. Chicago, IL: Ellingwood’s Thera-peutist; 1919.
Jurcic K, Melchart D, Holzmann M, Martin P, et al. Zwei Probandenstudien zur Stimulierung der Granulozyten-phagozytose durch Echinacea-Extrakt-haltige Präparate. Z Phytother 1989;10:67-70.
Parnham MJ. Benefit-risk assessment of the squeezed sap of the purple coneflower (Echinacea purpurea) forlong-term oral immunostimulation. Phytomed 1996;3:95-102.
British Herbal Medicine Association. British Herbal Pharmacopoeia. Cowling: BHMA; 1983:80-81.
Alternative Medicine Review ◆ Volume 6, Number 4 ◆ 2001 Page 413
Copyright2001 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission British Herbal Medicine Association. British Herbal Compendium. Vol 1. Bournemouth: BHMA; 1992:81-83.
Leung AY, Forster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd Ed.
New York-Chichester: John Wiley; 1996:216-220.
Weiss RF. Herbal Medicine. (Translated by Meuss AR from the Sixth German Edition of Lehrbuch derPhytotherapie). Beaconsfield: Beaconsfield Publishers Ltd; 1988:229-230.
Schar, D. Echinacea, The Plant That Boosts Your Immune System. London: Souvenir Press Ltd.; 1999.
Melchart D, Linde K, Worku F, et al. Results of five randomized studies on the immunomodulatory activity ofpreparations of Echinacea. J Altern Complement Med 1995;1:145-160.
See DM, Broumand N, Sahl L, Tilles JG. In vitro effects of Echinacea and ginseng on natural killer and antibody-dependent cell cytotoxicity in healthy subjects and chronic fatigue syndrome or acquired immunodeficiencysyndrome patients. Immunopharmacology 1997;35:229-235.
Melchart D, Linde K, Fischer P, Kaesmayr J. Echinacea for preventing and treating the common cold. CochraneDatabase Syst Rev 2000;CD000530.
Henneicke-von Zepelin H, Hentschel C, Schnitker J, et al. Efficacy and safety of a fixed combinationphytomedicine in the treatment of the common cold (acute viral respiratory tract infection): results of arandomised, double blind, placebo controlled, multicentre study. Curr Med Res Opin 1999;15:214-227.
Brinkeborn RM, Shah DV, Degenring FH. Echinaforce and other Echinacea fresh plant preparations in thetreatment of the common cold. A randomized, placebo controlled, double-blind clinical trial. Phytomedicine1999;6:1-6.
Lindenmuth GF, Lindenmuth EB. The efficacy of Echinacea compound herbal tea preparation on the severity andduration of upper respiratory and flu symptoms: a randomized, double-blind placebo-controlled study. J AlternComplement Med 2000;6:327-334.
Turner RB, Riker DK, Gangemi JD. Ineffectiveness of Echinacea for prevention of experimental rhinovirus colds.
Antimicrob Agents Chemother 2000;44:1708-1709.
Grimm W, Muller HH. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on theincidence and severity of colds and respiratory infections. Am J Med 1999;106:138-143.
Tragni E, Galli CL, Tubaro A, et al. Anti-inflammatory activity of Echinacea angustifolia fractions separated onthe basis of molecular weight. Pharmacol Res Commun 1988;20:S87-S90.
Tubaro A, Tragni E, Del Negro P, et al. Anti-inflammatory activity of a polysaccharide fraction of Echinaceaangustifolia. J Pharm Pharmacol 1987;39:567-569.
Tragni E, Tubaro A, Melis S, Galli CL. Evidence from two classic irritation tests for an anti-inflammatory actionof a natural extract, Echinacina B. Food Chem Toxicol 1985;23:317-319.
Hayashi I, Ohotsuki M, Suzuki I, Watanabe T. Effects of oral administration of Echinacea purpurea (Americanherb) on incidence of spontaneous leukemia caused by recombinant leukemia viruses in AKR/J mice. NihonRinsho Meneki Gakkai Kaishi 2001;24:10-20.
Steinmuller C, Roesler J, Grottrup E, et al. Polysaccharides isolated from plant cell cultures of Echinaceapurpurea enhance the resistance of immunosuppressed mice against systemic infections with Candida albicansand Listeria monocytogenes. Int J Immunopharmacol 1993;15:605-614.
Miller LG. Herbal medicinals: selected clinical considerations focusing on known or potential drug-herb interac-tions. Arch Intern Med 1998;158:2200-2211.
Bauer R, Hoheisel O, Stuhlfauth I, Wolf H. Extract of the Echinacea purpurea herb: an allopathicphytoimmunostimulant. Wien Med Wochenschr 1999;149:185-189.
Collins E, Berkoff N. Everything You Need to Know About Echinacea and Immunity. Roseville, CA: PrimaPublishing; 1999:85-86.
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Copyright2001 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission

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