Butterbur extract is taken mainly from the rhizome, root and leaves of the butterbur, a member of the daisy family. They are very hardy and have creeping underground rhizomes and large leaves like those of rhubarb. Another name given to it is the sweet Coltsfoot, and they generally grow in the temperate climates of Europe, North Africa and South west Asia. They like damp conditions, specifically marshes and ditches, and also riverbanks where there are always plentiful supplies of moisture.



It has been used by Native Americans for headaches and inflammation, and has been shown to be an effective remedy for hay fever and to provide relief from painful menstrual cramps. Butterbur has also been used throughout the middle Ages to treat fever and the plague, and has been recorded in the seventeenth century as being used for asthma, wounds and coughs. However, one of its most important applications is in restore bladder function in the incontinent and semi-incontinent.

Urinary incontinence is typified by an unusually high frequency of urination ? more than 8 times a day, an immediate strong urge to pass water or leaking and involuntary urination. Any two of these three indicates urinary incontinence. As people age their bladders become smaller, and by definition the periods between urination will reduce. This does not, however, suggest that bladder size is the cause of urinary incontinence.

Urination is caused by the contraction of the smooth layered muscle that surrounds the bladder, called the detrusor, a contraction in turn caused by neurons both in the brain and in the detrusor itself. This naturally contracts and expands according to the volume of urine in the bladder, and once the bladder is about half full the brain will tell you that the detrusor is ready to contract to expel the urine. However, if the time is not convenient, the cortex will suppress this desire until a more convenient time.

In incontinence, the desire is suppressed but the neurons still fire to contract the detrusor, expelling urine at inconvenient moments. Butterbur contains the sesquiterpenes petasin and isopetasin, which are known to reduce spasms in smooth muscle tissue and in vascular walls. It can therefore be used to control the involuntary spasms that cause urine leakage or expulsion against the patient's wishes. These sesquiterpenes are at highest concentration in the roots of the plant.

The effect that the sesquiterpenes have in inhibiting the synthesis of leukotriene in leukocytes tends to support this effect, since leukotrienes can cause contraction of vascular and smooth muscle tissue. Not only this, but the spasmolytic effect could also be explained by the inhibition of cellular calcium caused by the petasin isomers.

Many studies have indicated that the effectiveness of butterbur extract is also useful in the prevention of migraines. There has been a lot of research carried out on the use of butterbur extract on migraine sufferers, and the effective dose appears to about 75 mg twice daily. There is little evidence of it being a cure but as a prophylactic there appears no doubt of its efficacy: there have been too many positive results against placebos for its effect to be deniable.

It is significant that leukotriene can cause constriction of the small blood vessels in the veins, and so affect the flow of blood. Butterbur, in inhibiting its biochemical production, helps to keep these blood vessels open. Lekotrienes are also important components of inflammation, and altogether it appears that whatever the real cause of migraine, the petasin isomers in butterbur have an effect in inhibiting its initiation. Add to that the potential reduction in calcium content that can cause blood vessels to become less flexible, and the argument for its effectiveness is both irrefutable and well explained.

In one example of such a double blind study that is representative of many, a group of patients given 50 mg butterbur extract twice a day for twelve weeks experienced a 60% reduction in the frequency of attacks, a reduction in the severity of the attacks they did have, and a reduction in the length of the attacks. Although the vascular theory of the cause of migraine is no longer supported, maintenance of the vascular system appears to at least reduce the likelihood of attacks.

The effect of butterbur on asthma and other allergic reactions is also well documented. This again is due to its anti-spasmodic properties and inhibitory effect on the inflammatory immune response through the inhibition of leukotriene synthesis and the consequent positive effect on the metabolism of prostaglandin. Prostaglandins also constrict vascular smooth muscle cells, regulate the mediation of the inflammatory response and constrict general smooth muscle cells. All of these can lead a to a variety of disorders cause by smooth muscle spasms in additional to urinary incontinence, such as menstrual cramps, liver and gastrointestinal disorders and asthmatic conditions.

In one study of allergic rhinitis, administration of butterbur extract appeared to result in a reduction in the histamine and leukotriene content of nasal fluids and no difference was noticed between this treatment and histamine treatment. This was a useful study because histamines causes drowsiness and butterbur can be used as a substitute for histamine without the sedative effect. A study in Germany in 1993 has shown that the stomach ulceration caused by the anti-inflammatory medications for arthritis was reduced by the administration of butterbur extract

Cetirizine is a commonly prescribed prescription treatment for allergic conditions, and studies comparing that with butterbur demonstrated them to be equally effecting in reducing the symptoms typical of allergic reactions such as sneezing, runny nose and nasal congestion. 50% of the patients in the group took each and there was no difference in results. Again it was explained by the petasin limiting the production of leukotriene and histamine, both of which are produced by the immune response and promote mucous secretions and inflammation. They also constrict airways that can be serious to asthma sufferers

These studies are simply providing scientific evidence and explanations for the tradition use of this plant for such conditions. Butterbur has been used for centuries to treat such conditions all over Western Europe, and once again the use of traditional medicine has been supported by modern investigative techniques.