- 1 Echinacea: Medical Uses
- 2 Historical Uses
- 3 Growth
- 4 Parts Used
- 5 Major Chemical Compounds
- 6 Mechanism of Action
- 7 Echinacea: Clinical Uses
- 8 Echinacea: Dosage
- 9 Side Effects
- 10 Contraindications
- 11 Herb-Drug Interactions
- 12 Pregnancy and Breast-Feeding
- 13 Pediatric patients
- 14 Echinacea: Summary of Studies
- 15 Warnings
Echinacea: Medical Uses
Native Americans and Eclectic physicians used echinacea as a natural anti-infective for colds and flu. Native Americans first introduced echinacea to the colonists.
There are nine species of echinacea. This perennial will grow in most herb gardens in the northeast. The beautiful flower of E. purpurea, commonly called “purple cone-flower,” may grow up to 6 feet tall. E. angustifolia has narrow leaves and is much shorter, at about 2 feet. It has pink flowers. E. pallida grows to about 3 feet and is much paler. All three species have been cultivated in the U.S. and Europe. E. angustifolia is listed as an at-risk endangered herb.
• Aerial (above-ground) parts
• Whole plant and root
Major Chemical Compounds
• Caffeic acid derivatives
• Cichoric acid
Not all active chemical compounds are found in each species of echinacea.
Mechanism of Action
Alkylamides, which cause a tingling sensation on the tongue, produce anti-inflammatory effects by inhibiting cyclooxygenase. They also stimulate the immune system. The roots of E. angustifolia are highest in alkylamides. E. pallida contains alkylamides only in the aerial parts of the plant and not in the root.
Caffeic acid inhibits the spread of infection. Cichoric acid causes phagocytosis.
Polysaccharides enhance the immune system and exert wound-healing effects. They activate macrophages. Polysaccharides are the major compounds in E. purpurea.
Glycoproteins are highest in E. purpurea, which causes the highest stimulation of macrophages and contains cichoric acid.
Echinacea: Clinical Uses
Echinacea is used for the common cold, infections, and low immune status. It is also used as adjuvant therapy with antibiotics and chemotherapy and acts as an anti-inflammatory. Recent studies suggest that echinacea appears to work more effectively when taken at the first sign of a cold than when used as a daily preventative. Echinacea is approved by the German Commission E and the World Health Organization for “supportive therapy of colds, flu, respiratory and urinary infections”. It also may help in radiation exposure. The University of Arizona is currently investigating the use of echinacea in the prevention of recurrent otitis media.
Controversy exists over how echinacea should be standardized; the United States standardizes to a single chemical compound rather than the entire extract, which is more effective.
For acute infection: 20 drops of standardized tincture or 1 capsule every 2 hours at the start of a cold for up to 48 hours. The tincture may be added to a small amount of warm water or juice. After 48 hours, take 30 drops of tincture or one 300-mg dose of a dry standardized extract three times daily. Chichon recommends using echinacea as an antibiotic for a maximum of 2 weeks.
For prevention of infections (studies are controversial): 10 to 25 drops daily or 1 to 2 capsules or tablets daily. During long-term use, it is recommended that the patient spend 1 week without echinacea after every 8 weeks of taking it.
One case of an anaphylactic reaction has been reported in which the patient had an allergy to ragweed.
• Acute toxicity has been noted at dosages over 3 mg/kg.
• Echinacea was adulterated before 1988.
Taking echinacea for more than 8 weeks along with anabolic steroids, methotrexate, amiodarone, or ketoconazole increases the risk of hepatotoxicity. It may have antagonistic effects with immunosuppressants, such as corticosteroids and cyclosporin.
Pregnancy and Breast-Feeding
Echinacea is safe with oral use.
The children’s dose can be calculated using Young’s or Clark’s rule.
Echinacea: Summary of Studies
Echinacea is well researched, with over 350 studies. All German studies have been done with the expressed juice of E. purpurea.
Braunig et al. (1992). In this double-blind, placebo-controlled study of 180 volunteers using an alcohol extract of E. purpurea root, echinacea decreased the symptoms and duration of the flu. At 900 mg/day, patients showed a statistically significant improvement in symptoms within 3 to 4 days compared to placebo and to an echinacea dose of 450 mg.
Brinkeborn et al. (1998). In this study, 199 patients took echinacea extract or placebo at the first sign of a cold. Physicians found that echinacea extract was effective in 68 percent of cases, and 78 percent of patients reported that they found it effective. E. purpurea aerial parts and root were used and taken in doses of 2 tabs t.i.d. over 8 days. The tablets contained a dosage of extract equal to about 240 mg of echinacea per day. Both patients and physicians agreed that Echinaforce and Bioforce reduced cold symptoms better than placebo.
Hoheisel et al. (1997). In this randomized, double-blind, placebo-controlled clinical trial, 120 patients ingested 20 drops of echinacea every 2 hours for the first day after cold symptoms began and then t.i.d. for up to 10 days. Patients reported that only 40 percent of those who took the echinacea progressed to a cold compared to 60 percent in the placebo group. Patients who took the echinacea had colds that lasted 4 days compared to 8 days in the placebo group.
Shoneberger (1992). In this double-blind,placebo-controlled study, 108 volunteers with chronic upper respiratory infections took 2 to 4 mL/day of E. purpurea fresh juice extract. The treatment group had milder symptoms, briefer infections, and a longer period between infections.
Baetgen (1988). This study looked at the treatment of acute bronchitis in children using three groups: one group (n=468) took echinacea juice; one group (n=330) took echinacea and chemotherapeutics; and one group (n=482) took chemotherapeutics alone. Results: After 5 days, 45 percent of the group who took only echinacea experienced a cure. After 10 days, there was no difference between the three groups. Chemotherapeutics did not help viral infections. Tetracycline and chloramphenicol prevented healing.
Stimpel et al. (1984). Polysaccharides of E. purpurea were shown to strongly activate macrophages without toxic effects. These results have relevance for tumors and infectious systems.
Currier & Miller (2001). Daily doses of E. purpurea in vivo to leukemic mice demonstrated positive effects.
Lindenmuth (2000). In a randomized controlled trial, 95 subjects were given Echinacea Plus tea at the onset of cold and flu symptoms. Results showed that the tea was effective in relieving the symptoms of cold and flu in less time than placebo.
• Echinacea may cause allergy symptoms in some people.
• Echinacea may be toxic when taken in large amounts.
• Don’t take echinacea with any of these medications: anabolic steroids, methotrexate, amiodarone, ketoconazole, corticosteroids, or cyclosporin. Talk with your healthcare practitioner.