In my previous blog, I discussed the little-known use of ragweed for allergies. Another herb that can give over-the-counter antihistamines a run for their money is butterbur (Petasites hybridus). About 20 percent of Americans complain of allergies each year, often interfering with normal work and recreational activities. Butterbur, like ragweed, is a member of the Asteraceae family whose abundant pollen wreaks annual havoc on those who are sensitive to them.
A study published in August 2005 in Phytotherapy Research looked at 330 patients who suffered from sporadic hay fever. The study divided the participants into three groups: the first took 8 mg of butterbur extract three times a day; the second took 180 mg of fexofenadine (Allegra), a common antihistamine, each morning, and the last took a placebo.
At the end of the study, both groups receiving active treatment reported a significant reduction in the nasal congestion and itchy, watery eyes most commonly experienced with hay fever. Most strikingly, there was almost no difference between taking an antihistamine or the butterbur extract, except that some taking the antihistamine complained of drowsiness.
Since antihistamines and butterbur work in different ways, study author Dr. Andreas Schapowal of the Allergy Clinic in Landquart, Switzerland, feels that combining the two drugs would be effective. However, no study has investigated how butterbur works in combination with any other drug.
Butterbur: Antispasmodic and anti-inflammatory properties find use in migraines, allergies
The active ingredients in butterbur extracts are petasin and isopetasin. Petasin reduces spasms in smooth muscle and vascular walls, while isopetasin acts on the system that reduces inflammation. Together, the two act as an effective anti-inflammatory drug with potential in treating many ailments. These anti-spasmodic and anti-inflammatory properties have been demonstrated in pharmacological and experimental systems. Butterbur regulates calcium channels and inhibits the synthesis of the enzymes lipoxygenase and cyclooxygenase. Efficacy and tolerability of butterbur was demonstrated in two randomized, double-blind and placebo-controlled clinical trials with more than 300 adult patients and in one open trial in 108 children and adolescents.
Petasin also provides an inhibitory action on the leukotriene and histamine. The former is responsible for the allergic reactions in human body, when the blood vessels are dilated and get permeable causing such symptoms as rhinitis and sneezing. The latter causes inflammation and provokes the symptoms of asthma and hay fever. Therapeutic effects of petasin are applicable for such conditions as kidney stones, menstrual cramps, urinary disorders, and gastrointestinal problems (ulcers in particular) associated with muscle spasms and inflammation. In addition, petasin is known to provide hypotensive actions and strenghthen cardiac tissue.
Medical studies have proved that butterbur extract helps both in prevention and treatment of migraine, especially in severe cases and with fewer side effects (e.g. sedative) than in typical headache preparations. This action is supposedly achieved by relieving pressure on blood vessels and affecting calcium channels. An important feature of the herb's anti-migraine action is that it can be used in adolescents and even children. A study published in January 2005 showed that butterbur extract could help to prevent and reduce migraine symptoms better than placebo.
A few studies have implied that the extract may also be useful in treating asthma, bronchitis, and other respiratory disorders. "Three randomized, placebo-controlled studies of the butterbur extract, Ze 339, in peer-reviewed journals should convince anybody of the efficacy and safety of the medication in allergic rhinitis," said Schapowal.
Astralagin and isoquercitrin are flavonoid glycosides found among the other important chemicals in the herb. They provide anti-depressant properties for the human central nervous system.
Also, anti-oxidant and properties associated with butterbur have been noted in several studies.
The most common pharmaceutical form butterbur is being released in is the supplement called Petadolex. These are the butterbur gelcaps produced for relieving migraine symptoms. There are no recorded adverse reactions to the use of butterbur. However, older studies that have not been duplicated showed that butterbur leaf extract may have caused cancer in animals. Therefore it has gradually faded from human use. The compound responsible for this toxic effect, the pyrrolizidine alkaloid, has since been identified, and newer butterbur supplements are made from only the leaves of a plant (roots contain higher levels of the alkaloid) specially developed to be low in the compound. Now experts say that the herb is safe for use. Due to the risk of PA toxicity, butterbur should only be consumed processed and purchased from the authorized dealers. The raw extract should be avoided.
Historical use of butterbur
Butterbur has a long history of use, possibly dating back to ancient times. Related to comfrey and coltsfoot, it was used to treat asthma and sinus infections. In the 16th century it was described as a "plague flower," presumably because it may have been found effective in treating this disease. Native Americans used butterbur root for inflammation, hay fever and headaches, much as it is used today.
The size of the leaves made it useful as a head cover, which gave the butterbur its derived generic name. Petasus is a Greek word for a broad felt hat worn by shepherds, hence Petasites is the name of the genus. The plant's common name "butterbur" refers to another function of the leaves: they were used to wrap butter for preserving it and keeping it cool. In some cultures seeds of butterbur are believed to have love divination properties and are used for rituals by young women.
Butterbur is native to Europe as far north as Scandinavia, and is also naturally found in some parts of Asia and North America. It is considered invasive and due to its space and light-consuming habits, butterbur grows with no other plants around its leaves. Favoring clay and sandy loam, it is found in meadows, shades by the waterways, flood plains, marshes, and other damp areas.
The rhizome of the plant is considered to possess most of the beneficial properties associated with butterbur. It contains bitter resinous juice and has an unpleasant taste. Leaves are used for herbal extracts intended to manage allergies.