|
|
|
Butterbur - How Butterbur Works? - Side Effects of Use
Taxonomic Class
Asteraceae
Common Trade Names
Multi-ingredient preparations: Alzoon, Butterbur Root Extract, Feverfew/Dogwood Supreme, Neurochol, Petaforce, Wild Cherry Supreme
Common Forms
Available as 25-mg standardized capsules, Petasites extract, and liquid Petasites extract (concentration may vary).
Source
Active compounds of butter bur are extracted from the leaves, flowers, stems, and root stock of Petasites hybrid us, P. officinalis, mortising petasites. Some formulas use extract from the leaves and roots of P. frigidus, also known as P. palmatus, T. palmatum, or western coltsfoot. These plants are low-lying perennial herbs of the Compositae family.
Chemical Components
The active components of P. hybridus are believed to be isopetasin, oxopetasin esters, and petasin. Several studies have found petasin, a sesquiterpene ester of petasol and angelic acid, to be the most active component .lsopetasin and oxopetasin esters have been isolated. Other alkaloids isolated from P. hybridus include the pyrrolizidine alkaloids integerrimine, senecionine, and senkirkine as well as petasol and isopetasol P. frigidus contains petasin and related esters, saponins, resins, and volatile oils as well as small amounts of pyrrolizidine alkaloids. The latter occur in young leaves but not in the roots, which are more often used in commercial extracts .
Actions
Studies with animals have found that P. hybridus extracts possess antiinflammatory and spasmolytic properties. The extracts reduced intestinal ulcerations and blocked gastric damage in rats. The effects were dose-dependent.
Extracts also inhibited peptido-leukotriene biosynthesis in mouse peritoneal macrophages and did not affect prostaglandin synthesis. Proposed mechanisms include inhibition of 5-lipoxygenase or interference with the use of calcium ions in leukotriene production .
In 1953, studies found a cytostatic effect of Petasites extract on fertilized sea urchin eggs, leading to the agent being used later as an analgesic for cancer patients. This effect is not substantiated in other available literature.
Some work is being done examining P. hybridus' effects on dopamine 2 and histamine1 receptors.
Reported Uses
Butterbur has been used for thousands of years for GI disorders and GI-related pain as well as for asthma, cough, skin diseases, and spasms of the urogenital tract . Other therapeutic claims include its use as an antarthritic, an astringent for cosmetic purposes, a diuretic, and a sedative. Butterbur was prescribed in ancient times as an ointment for ulcers and sores . References have also been made to an analgesic effect of Petasites extracts, but this effect may be secondary to the herb's spasmolytic properties.
P. frigidus may be taken as a tea or smoked. It may also be used as a poultice by patients who reside in areas where the plant is endemic, including the United States.
Dosage
No consensus exists.
Adverse reactions
-
EENT: eye discoloration.
-
GI: abdominal pain or pressure, sustained constipation, discoloration of stool, dysphagia, severe nausea, vomiting.
-
GU: difficulty urinating.
-
Hepatic: hepatotoxicity.
-
Respiratory: difficulty breathing.
-
Skin: skin discoloration.
Interactions
None reported, but administration of butterbur with anticholinergics may not be advisable.
Contraindications And Precautions
Avoid using Petasites extracts in pregnant or breast-feeding patients; effects are unknown. Also avoid using butterbur in patients with decreased GI or bladder motility because symptoms of these disorders may worsen.
Special Considerations
Discourage the use of butter bur in patients with disorders that might be worsened by any effect on leukotriene synthesis or calcium modulated smooth-muscle contractility, especially in the GI tract. Also discourage its use in patients with underlying disorders that may become dangerous if inadequately treated, such as asthma.
Alert Carcinogenic and hepatotoxic effects may result from the presence of pyrrolizidine alkaloids in the plant .
Monitor for adverse reactions, and notify the health care provider if any occur.
Advise women to avoid using butterbur during pregnancy or when breast-feeding.
Commentary
Despite the use of butter bur extracts for centuries, little information is available to establish safety and efficacy in the prevention or treatment of any diseases in humans. Although studies with animals suggest a possible mechanism of action for reducing smooth-muscle spasms and inflammation, studies in humans are lacking.
Further research may reveal a beneficial effect of the more active components of Petasites extracts, but purification and standardization of these extracts are needed before reliable claims can be made. The active components of Petasites extract can vary from one batch to another, and potentially hazardous alkaloids have been identified in these plants.
