Of all the herbals used as traditional medicine, Echinacea produces some of the most consistent results and has an unblemished record of safety in all situations. Echinacea species are natural to North America and three species are commonly used, E. angustifolia, E. purpurea and to a lesser extent E. pallida.
The active components of Echinacea are complex and contribute to its wide range of therapeutic activities. The major categories are shown below:
|
Caffeic acid derivaties |
e.g. echinacoside |
| Allylamides |
e.g. echinacein |
| Flavonoids |
e.g. rutocide |
| Polyacetylenes |
|
| Polysaccharides |
e.g. arabinose-based polymers |
The major physiological activities of Echinacea can be classified as follows:
- Stimulation of cell-mediated immunity. Wide evidence of stimulation of:
- natural killer cells
- phagocytes
- T-helper cells directed to cell mediated immunity
- Inhibition of hyaluronidase.
Hyaluronic acid is a high molecular weight mucopolysaccharide that acts as a protective coat for many types of tissue cells. Some microorganisms, including Staphylococcus aureus, produce the enzyme hyaluronidase, which degrades hyaluronic acid and enables the host cells to be easily attacked. The polysaccharide component of Echinacea species appears to bind to the hyaluronic acid, making it resistant to hyaluronidase.
- Direct anti-viral activity. In in-vitro culture, Echinacea has been found to significantly decrease plaque (viral colony) numbers of viruses including Influenza and Herpes simplex (Wacker & Hilbig, 1978; Hobbs, 1989).
With this level and range of activity, Echinacea has become a mainstay natural remedy for a variety of conditions. Its safety record also means that it can be used long term and alongside other treatment modalities.
Echinacea is appropriate for use as:
- Anti-infective
- Anti-inflammatory
- Chemopreventative
- Immunostimulative (general)