General Description
Echinacea (also known as purple coneflower or snakeroot) is a perennial
plant with a stout, hairy stem 2 to 3 feet in height. The leaves
are thin, rough, and hairy, growing 3 to 8 inches long. Found throughout
midwestern North America from Texas to Saskatchewan, echinacea flowers
from July to October, bearing a large, cone-shaped blossom which
may range in color from whitish-pink to a pale purple. Of the nine
species of echinacea that have been identified, three (angustifolia,
purpurea, and pallida) are used for health purposes.
Health applications
History and traditional use
Native Americans used echinacea for a wide range of ailments and
injuries. Externally, the herb was used to treat wounds, burns,
and insect bites. It was taken internally for infections, joint
pains, and as an antidote for venomous snake bites (the reason echinacea
was commonly known as snakeroot). Echinacea was introduced into
U.S. medical practice in 1887, but fell out of use in the early
1900s. Modern studies of echinacea's medicinal properties began
in Germany in the 1930s. American interest in the herb was rekindled
in the early 1980s, and echinacea is now among the country's most
popular herbal dietary supplements.
Chemical composition
There are several compounds in echinacea that may be active in
the body, including echinacoside, cichoric acid, polysaccharides,
alkylamides, polyacetylenes, flavonoids, essential oils, resins,
glycoproteins, sterols, and fatty acids.1
Levels of these compounds vary with growing conditions and between
different species. Because compounds occur in varying concentrations
in different parts of the plant, many herbalists recommend whole-herb
extracts that use both the above-ground and underground portions.
Immune system support
Echinacea supplements are most commonly used to support the immune
system's ability to fight infection during a cold or flu. Numerous
clinical studies indicate that echinacea may be beneficial in
the prevention and treatment of the common cold (acute viral respiratory
infection).2-4 Greatest benefit was achieved
when treatment was started early in the cold's progression.3
It appears that echinacea stimulates the activity of the body's
natural killer cells, rather than exerting direct antiviral activity.5-11
Dosage/toxicity
The recommended dosage for echinacea varies with the quality and
the portions of the plant used and with the extraction methods
used in preparation. Most echinacea supplements have dosage recommendations
printed on their labels. The herb has an excellent safety record,
with no known side effects. Echinacea has no known toxicity, even
at several times the normal therapeutic dose.12
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