Echinacea: Biological Effects and Active Principles

Abstract

In recent years, Echinacea preparations have developed into the best selling herbal immunostimulants. Most of the products are derived from either the aerial or the underground parts of Echinacea purpurea, and from the roots of E. angustifolia or E. pallida. The common products in Europe mainly represent expressed juice preparations or alcoholic tinctures. The different species and preparations can be clearly distinguished phytochemically by their typical constituents. The most relevant compounds for standardization are caffeic acid derivatives (cichoric acid, echinacoside), alkamides, polyacetylenes, and glycoproteins/polysaccharides. Pharmacological studies have shown that cichoric acid, alkamides, and glycoproteins/polysaccharides possess immunomodulatory activity. Therefore they might be considered as active principles and best suited for standardization purposes. Clinical effects have been demonstrated for the expressed juice of the aerial parts of Echinacea purpurea in the adjuvant therapy of relapsing infections of the respiratory and urinary tracts, as well as for alcoholic tinctures of E. pallida and E. purpurea roots as adjuvants in the therapy of common cold and flu. Historical Use and Botanical Aspects of Echinacea SpeciesThe genus Echinacea is endemic to North America, where it occurs in the Great Plains in between the Appalachian Mountains in the east and the Rocky Mountains in the west. Its use can be traced back to the American Indians, who regarded Echinacea as one of the most favored remedies to treat wounds, snake bites, headache and the common cold (7). The territories of the tribes that most frequently used Echinacea, show a close correspondence with the distribution range of Echinacea angustifolia. Echinacea pallida and E. purpurea, and possibly other Echinacea species have also been used, however. 140

Effect of Black Mustard (Brassica nigra) on the Interaction between Immune and Biotransformation Systems of Nile Tilapia (Oreochromis niloticus) Exposed to Benzo-a-Pyrene

“…The extraction process plays an important role in determining the constituents of the extract and their concentrations. For example, the alcoholic extraction contains higher concentrations of hydrophobic alkamides and water extraction contains the more hydrophilic polysaccharides (Bauer, 1998). Accordingly, the extraction method and the resulting extracts may be completely different in their biological activity and action, in turn differ from the crude one.…”

Echinacea Inhibits Adenosine Deaminase Enzyme in Cancerous Human Gastric Tissue

“…Efficacy of Echinacea extracts in anticancer therapy has been proposed to be related to their well-documented immunostimulatory activities due to high molecular weight polysaccharides and alkylamides that, in turn, can induce a functional increase of natural killer cells [17,18]. There is evidence suggesting that some phytochemicals in Echinacea might have the capacity to reduce tumors and virus infections [19][20][21][22][23][24][25]. The immunostimulating effects of Echinacea in vivo are exclusive to cells mediating spontaneous immunity and their accessory cells [26].…”

Patterns of variation in lipophilic and hydrophilic constituents in flower developmental stages of Echinacea purpurea (L.) Moench cultivated in Slovakia

“…Therefore, cichoric acid, echinacoside, and alkamides (iso-butylamides) are generally used as indices of quality control for standardization of E. purpurea row material and finished products (Bauer 1998) and are the most likely candidates for the genus medicinal properties.…”