There are a number of classes of pharmacologically active chemicals in echinacea, including polysaccharides, flavonoids (calculated as quercetin), caffeic acid, essential oils, alkylamides, and polyacetylenes.
Echinacea has strong immune-stimulating properties. This herb increases phagocytosis (the ability of white blood cells to destroy invading organisms), stimulates the lymphatic system (to remove waste materials), and reduces the production of hyaluronidase (an enzyme that breaks down hyaluronic acid; hyaluronic acid is needed to bind cells together to prevent infection). The reduction of hyaluronidase is responsible for tissue regeneration and decreased inflammation.
THERAPEUTIC USES OF ECHINACEA
Echinacea is used as an immune stimulant and as an antimicrobial (antiviral and antibacterial) herb. In people, echinacea was the number one cold and flu remedy in the United States until sulfa antibiotics displaced it. Ironically, antibiotics are not effective for colds, while Echinacea appears to offer some help.
Echinacea remains the primary remedy for minor respiratory infections in Germany, where over 1.3 million prescriptions are issued each year. The best scientific evidence about echinacea concerns its ability to help people recover from colds and minor flus more quickly. Good evidence tells us that echinacea can actually help people get over colds much faster; it also appears to significantly reduce symptoms while people are sick. In people, studies of echinacea have used all three species of the herb. We don’t know which one is better, or whether they are all equivalent.
Echinacea is recommended as an antimicrobial for the urinary system. Echinacea is also recommended to be used internally and externally as an herbal remedy for snakebite.
ECHINACEA: SCIENTIFIC EVIDENCE Both test-tube and animal studies have found that polysaccharides found in echinacea can increase antibody production, raise white blood cell counts, and stimulate the activity of key white blood cells.
However, the meaningfulness of these studies has been questioned. Many other substances induce similar changes, including wheat, bamboo, rice, sugarcane, and chamomile, and none of these have ever been considered immune stimulants. We don’t know whether echinacea produces its effects by stimulating the immune system, or in some altogether different way. Its lack of effectiveness in preventing colds when taken over the long-term suggests that echinacea does not actually strengthen the immune system overall. In an uncontrolled study in people, echinacea decreased inflammation in patients with rheumatoid arthritis.
While controversial, many herbalists recommend using echinacea for five to seven days on, two to three days off, and then re-administering the herb. This schedule allows the body to rest and hopefully achieve a greater immune boost each time the herb is administered. In people, actual negative results were seen in one study. For a period of six months, 200 people were given either echinacea or placebo. Use of the herb was actually associated with a 20 percent higher incidence of sore throat, runny nose, and sinusitis. The authors suggest that long-term use of echinacea might actually slightly impair immune function.
Since echinacea requires a healthy immune system, it has been proposed that it should not be used in pets with immune disorders without veterinary supervision (feline leukemia or immunodeficiency virus infection, autoimmune diseases). This is based on suggestions made in human medicine, although studies dating back to the 1950s suggest that echinacea is safe in children.
Germany’s Commission E warns against using echinacea in cases of autoimmune disorders such as multiple sclerosis, lupus, and rheumatoid arthritis, as well as tuberculosis or leukocytosis. There are also rumors that echinacea should not be used by people with AIDS. These warnings are theoretical, based on fears that echinacea might actually activate immunity in the wrong way. But there is no evidence that echinacea use has actually harmed anyone with these diseases. In fact, it has been used in the therapy of cancer due to tis potential immunestimulating properties.
Many herbalists feel that liquid forms of echinacea are more effective than tablets or capsules in people, because they feel part of echinacea’s benefit is due to activation of the tonsils through direct contact.
Since echinacea works best with a healthy immune system, use of other herbs (such as Oregon grape and goldenseal) and a proper diet with nutritional supplements boosts the effectiveness of echinacea.
It remains controversial which species of echinacea is the “best” to use. Many experts consider the fresh-pressed juice of Echinacea purpurea to be the best preparation since this contains the greatest range of active compounds. Many experts recommend a minimum standard of 2.4 percent beta- 1, 2-fructofuranosides, which guarantees the plant was harvested in the blossom stage, was carefully prepared and stabilized. More research is needed to address this area of controversy.
Since wild echinacea is becoming endangered, cultivated echinacea or other immune stimulants (such as reishi) may be preferred.
SAFETY ISSUES For hyper-immune disorders (autoimmune diseases, diabetes) and disorders with diminished immune systems with low white blood cell counts (feline leukemia and immunodeficiency diseases), it may be wise to avoid this herb, as echinacea is used for immune stimulation. It is best used early in the course of the disease at the first signs of infection to properly and fully stimulate the immune system.
Echinacea appears to be safe. Even when taken in very high doses, it has not been found to cause any toxic effects. Reported side effects in people are also uncommon and usually limited to minor gastrointestinal symptoms, increased urination, and mild allergic reactions. The Commission E Monographs (an extensive guide to herbal medicine) also recommends against using echinacea for more than eight weeks. The safety of echinacea in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established. Similar side effects and warnings might be applied to pets. There are no known drug interactions.