Please note: Research on the medicinal uses of herbs, alone and in combination with synthetic drugs, is new and not yet definitive. If you already take prescription drugs, have a serious or chronic medical condition, or are just unsure if herbal remedies are appropriate for you, please consult with your physician before using them.
Echinacea has many varieties, but the three most commonly used for medicinal purposes are angustifolia, purpurea, and pallida. It originated in the United States and grows freely in the Plains states. Its bright, daisy-like flowers make it attractive enough to be grown as an ornamental-which it was, before its medicinal qualities were discovered.
Native Americans used echinacea for many ailments, including sore throat, toothache and other mouth pain, burns, snake bites, and distemper in horses. In the 19th century it was also commonly used for infections like colds and bronchitis, and it was applied topically (on the skin) as well. It was actually quite popular until the development of synthetic drugs like antibiotics. But recently it has returned to favor, and is now available in may different forms, including tea bags, capsules, and liquid extracts, as an ingredient in some skin ointments, and also dried.
Echinacea has many active ingredients, but its main ones are caffeic acid, cichoric acid, and echinacoside. It also contains alkylamines, which cause numbness when it’s chewed (which is probably why the Native Americans used it for mouth pain); as a matter of fact, this is how herbalists test the strength of a particular plant.
Research done mainly in Europe, particularly in Germany, has investigated its power to boost immunity, but how it does this is still uncertain. There are theories that it may increase properdin, which tells the body to release white blood cells in response to an infectious process. It’s also possible that the roots may have an action similar to interferon, an antiviral chemical produced by the body, or perhaps echinacea stimulates the body’s own production of interferon. It may also inhibit the action of integrase, which is used by the HIV virus to invade the DNA.
Germany’s Commission E has approved angustifolia and purpurea for treatment of upper respiratory infections (including colds, flu, and bronchitis), urinary tract infections, and for wounds (when used topically). In the case of colds, herbalists also recommend combining it with vitamin C, zinc lozenges, garlic, and goldenseal.
New research has shown that there may be other therapeutic uses for echinacea. For example, it may slow the destruction of collagen from prolonged exposure to the sun. Collagen helps the skin stay elastic, so this effect could be beneficial for aging skin.
Echinacea has been used to treat hepatitis C along with Lasix (a synthetic diuretic), silymarin from milk thistle, and dandelion. And it has been used to treat chronic sinusitis.
There is some debate over whether echinacea is useful only during illness, or as a preventive as well. In Germany, a study used it along with econazole nitrate to treat chronic yeast infections. Subjects who took both econazole and echinacea had a lower rate of recurrence than those who took only econazole-which would show some preventive effect. Most herbalists, though, agree that even if you’re taking echinacea-or any herb-on a regular basis, it’s a good idea to take a break periodically-for example, by skipping one day a week, or one week every six weeks.
Commission E has not found any side effects or drug interactions, but it’s probably a good idea to avoid echinacea or use it with caution in pregnancy, lactation, and autoimmune disorders like multiple sclerosis, tuberculosis, and HIV/AIDS. In the last case, there is conflicting evidence of whether echinacea is helpful or harmful. Although it may inhibit integrase, it has also been known to stimulate the HIV virus-although that study, like many looking for side effects, was done using megadoses of the herb. More research needs to be done on its action against integrase before it can be recommended for patients with HIV/AIDS.