Echinacea

Occurrence

Echinacea is a perennial found in only three states: Missouri, Nebraska, and Kansas. It is cultivated in much of the world. Echinacea is a Native American remedy.

The Uses of Echinacea

echinacea (Echinacea angustifolia) is also known as coneflower. echinacea is well known for its ability to boost the body’s immune system. It is described as having antiseptic and anti-bacterial properties rendering it helpful in treating skin lesions and in shortening skin healing time. It also has anti-itching, soothing, and moisturizing properties when used in skin care products. It is commonly used in acne preparations. The main constituents of both the oil and the resin, derived from the wood or bark of the plant are inulin, inuloid, sucrose, betaine, phytosterols, and fatty acids such as oleic, cerotic, lizolic, and palmitic.

Indications

The purple coneflower Echinacea purpura, and its close relatives, E. angustifolia and E. pallida, are the source of the herb Echinacea, which is widely popular as a nonspecific immune stimulant. These perennials are native to the prairies of North America and are now widely grown garden ornamentals.The root and aerial parts of the plant are the portions used, and the preparation’s potency can be verified by the transient tingling sensation produced when it is tasted. Echinacea contains alkamides, caffeic acid esters (echinacoside, cichoric acid, caftaric acid), polysaccharides (heteroxylan), and an essential oil. Some echinacea products are standardized for their echinacoside content. In the past, adulteration with American feverfew (Parthenium integrifolium) was common. Echinacea is now sold either by itself or in combination with golden seal or zinc for the treatment of colds and influenza.

General Description

One estimate stated that, in Germany alone, there are 800 echinacea-containing drugs, including several homeopathic preparations. Three species are identified as echinacea: E. angustifolia, Echinacea pallida, and Echinacea purpurea. All are used for medicinal purposes, and they have similar properties. There are slight differences among the species with regard to the anatomical distribution of active constituents. There is no doubt that echinacea has immunomodulating properties. The chemistry of the constituents of the plant has been studied extensively, but it is difficult to correlate a major activity with any plant fraction.

Mechanism of action

Echinacea extracts appear to stimulate the number and activity of immune cells (i.e., increasing physiological levels of tumor necrosis factor and other cytokines)and to increase leukocyte mobility and phagocytosis.The extracts also have antiviral and antiinflammatory properties and inhibit bacterial hyaluronidase.

Clinical Use

There are numerous studies on echinacea in the literature, many of which indicate either an in vitro immune stimulation or a significant clinical reduction in the severity and duration of upper respiratory viral symptoms, especially when taken early in the onset of symptoms. Despite several of these meta-analyses concluding that echinacea is an effective immunomodulator of acute infection, there is still controversy as to the extent of its clinical effectiveness. A number of trials now clearly indicate that echinacea is unlikely to be effective in the prevention of colds, even if it may slightly shorten their course.
In vitro antiinflammatory effects have been documented, and the herb has a long history of being used externally for wound healing, psoriasis, and the reduction of skin irritation. Although there are a few small positive studies, the available e

Side Effects

Echinacea appears to be a very safe herb, producing only minor gastrointestinal (GI) side effects and an occasional allergic reaction, usually in atopic patients already sensitized to other members of the Compositae plant family. Anaphylaxis has occurred rarely. Use in HIV is discouraged because of the concern that long-term therapy may eventually suppress the immune system.
It is recommended that echinacea not be taken by anyone for more than 8 continuous weeks, and most clinical use is under 2 weeks’ duration. Echinacea has not yet been shown to be safe in pregnant or breastfeeding women and small children. No specific herb–drug interactions are reported, but for theoretical reasons those taking immunosuppressant drugs should avoid echinacea.