Echinacea

 

Andrew Halpner, Ph.D. Echinacea, a member of the daisy family, was first introduced into medicine by a Nebraskan doctor who learned of its value from the Indians in 1871. At that time the herb was claimed to be effective at treating every disease, including rheumatism, migraine, infections, pain, eczema, malaria, hemorrhoids, tumors etc. Like other herbs, most of the research surrounding Echinacea has been conducted in Germany and Europe, with much of the literature in non-English languages. Of all its proported actions, its immuno-enhancing effect appears to have the most substantiation. Clinical trials investigating the effectiveness of Echinacea have provided us with compelling information regarding its effectiveness.

There are two species of Echinacea commonly used, E. angustifolia, and E. purpurea.

The latter has become most popular and is now the commonly cultivated species.

Numerous compounds identified in the herb have been shown to exhibit antiviral and immunostimulatory properties. Polysaccharides contained within Echinacea extracts have been demonstrated to enhance non-specific cell-mediated immunity, increasing the production of cytokines such as IL-1, IL-6, IL-10 and TNF-a. These same polysaccharides have also been reported to have anti-inflammatory activity, and can reduce leukocytic infiltration associated with dermatitis.

Although the number of clinical trials investigating Echinacea are somewhat limited, the data are very encouraging. Hoheisel et al. examined the expressed juice of E. purpurea on its ability to shorten the duration of the common cold in a group of Swedish factory workers. Patients were randomized to receive either 20 drops of expressed juice in water every 2 hours for the first day and thereafter, 3 times daily for up to 10 days, or placebo.

The authors reported that subjects receiving the extract demonstrated a significantly more rapid time to recovery compared with placebo. The median time to improvement was 4 days for the treated group compared with 8 days for the placebo group. No specific adverse reactions were observed. It should be noted that the extract used in the above study was the expressed juice. While other positive studies have used dry extracts, the results of studies using the expressed juice of the flowering tops of the plant have resulted in the expressed juice becoming a popular form for this immune-boosting herb.

Most of these juice preparations are made by steeping the herb in alcohol for an extended period in order to extract the beneficial components. Unfortunately, the resulting liquid then contains a significant amount of alcohol. For those concerned with ingestion of excess alcohol (especially children), this may not be the most appropriate form. Consequently, a process has been developed whereby the herb is steeped in alcohol for one year, which is then followed by the removal of the alcohol. The alcohol is removed by a process filtering and distillation at temperatures below 30¡ C. The low temperatures allow for the maintenance of the integrity of the components, including the polysaccharides. The remaining mixture is then combined with maltitol, resulting in a pleasant tasting Echinacea syrup that is both alcohol and sugar free as well as suitable for children.

Safety/Toxicity

Animal studies have not reported any toxic effects from doses of Echinacea many times greater than what is typically consumed by humans. Carcinogenicity tests in hamster embryo cells have also proven negative. Debate remains concerning long term, chronic supplementation with Echinacea. While no clinical studies have reported that supplementation with Echinacea continuously for an extended period of time results in any down regulation of the immune system, many still recommend that it be taken at the onset of the cold, continued for the duration of the cold, and then stopped.

Publisher:
Peter W. Hefele

Editor In Chief:
Andrew D. Halpner, Ph.D.

Assistant Editor:
Michael Traficante

Assistant Editor & Research:
Natalie Shamitko

Technical Advisors/Contributors:
Nita Bishop, Clinical Herbalist
Martin P. Gallagher,M.S., D.C.
Mitchell J. Ghen, D.O., Ph.D.
Brad Lichtenstein, N.D.
Derek DeSilva Jr., M.D.
James Wilson, Ph.D.