Echinacea, also known as purple coneflower, is the root or above ground parts (harvested in flower) of three species of large, robust daisy like plants of the aster family. Echinacea angustifolia and E. pallida are harvested from the prairies of the midwestern United States. Some commercial cultivation of these two species has developed as they become more scarce in the wild. E. purpurea, also native to the Midwest, is the most widely used species of the three. The entire world supply is cultivated.
Native Americans of the prairie used echinacea for more medicinal purposes than they did any other plant, for everything from colds to cancer. It entered formal medicine in 1895, becoming the best-selling American medicinal plant prescribed by physicians into the 1920s. Later replaced by antibiotics in the United States, it has enjoyed continuous popularity in Europe. In 1993 German physicians prescribed echinacea more than 2.5 million times. Traditionally, herbalists consider it a blood purifier and aid to fighting infections.
Today most consumers use echinacea to prevent and treat colds and to help heal infections. Echinacea enhances the particle ingestion capacity of white blood cells and other specialized immune system cells, thus increasing their ability to attack foreign invaders, such as cold or flu viruses. Besides stimulating a healthy immune system to deal more effectively with invading viruses, it helps accelerate healing if infection already exists.
A 1992 German double-blind, placebo-controlled study of 180 volunteers found that a dose of 4 droppers of tincture (equivalent to 900 mg of dried root) of E. purpurea root decreased symptoms and duration of flulike infections. More clinical studies are needed to determine clear therapeutic indications, the best preparations, and the most effective dosage. The best-studied echinacea is a preparation made from the fresh expressed juice of E. purpurea. No single chemical component has been identified as causing echinacea's medicinal action, but it may involve flavonoids, essential oils, polysaccharides, caffeic acid derivatives, alkylamides, and other compounds.
Echinacea products include tablets, capsules, flex-tabs, and liquids such as tinctures, extracts, and the expressed juice of the fresh flowering plant, on which most research has been done. Some products are standardized to echinacoside, a derivative of caffeic acid, but this compound may not be involved in stimulation of the immune system.
Persons who are allergic to the pollen of other members of the aster family, such as ragweed, may also be allergic to echinacea. The German government recommends that nonspecific immunostimulants, including echinacea, should not be used in cases of impaired immune response (involving diseases of the immune system itself) including tuberculosis, multiple sclerosis, and HIV infection.
Flu Infections, minor
Prevents or reduces cold symptoms