Petasites#Medicinal uses

The genus name is derived from the Greek word {{lang|el|πέτασος}} petasos, from the plant's broad leaves resembling a wide-brimmed hat.{{cite web |url=https://www.drugs.com/npp/butterbur.html |title=Butterbur |date=14 February 2022 |publisher=Drugs.com |access-date=3 May 2023}}

;Accepted species

• Petasites albus – white butterbur – Europe, Algeria, Turkey, Caucasus, India
• Petasites fominii – Republic of Georgia
• Petasites formosanus – Taiwan
• Petasites frigidus – Arctic butterbur or Arctic sweet coltsfoot – Scandinavia, Mongolia, Canada, northern USA
• Petasites hybridus – common butterbur – Europe, Mediterranean
• Petasites japonicus – giant butterbur, fuki – China, Japan, Korea
• Petasites kablikianus – southeastern Europe from Poland to Albania
• Petasites kamengicus – Arunachal Pradesh
• Petasites paradoxus – central + southwestern Europe from Spain to Poland
• Petasites pyrenaicus syn. Petasites fragrans - winter heliotrope - from Azores to Ireland + Tunisia
• Petasites radiatus – Mongolia
• Petasites rubellus – Mongolia, Manchuria, Korea
• Petasites sibiricus – Siberia
• Petasites spurius – Europe, Siberia, Caucasus, Central Asia
• Petasites tatewakianus – Siberia, Russian Far East, northeastern China
• Petasites tricholobus – China, Vietnam, Himalayas
• Petasites versipilus – Sichuan, Yunnan

;Species of hybrid origin

• Petasites × vitifolius

;Species formerly included

Petasites glacialis (Ledeb.) Polunin - Endocellion glaciale (Ledeb.) Toman

The short spikes of flowers are produced just before the leaves in late winter (e.g. Petasites fragrans) or spring, emerging with only a few elongated basal bracts and are usually green, flesh coloured or dull white depending on the species. It is dioecious, with male and female flowers borne on separate plants.{{cite journal|doi=10.1080/20423489.2016.1271383|title=A new natural hybrid in the genus Petasites: P. japonicus × P. pyrenaicus (Asteraceae)|year=2016|last1=Desjardins|first1=Stuart D.|last2=Hoare|first2=Arthur G.|last3=Stace|first3=Clive A.|journal=New Journal of Botany|volume=6|issue=2–3|pages=64–70|bibcode=2016NJBot...6...64D |s2cid=90843775|url=https://figshare.com/articles/journal_contribution/4668331 |url-access=subscription}}

Butterbur can be found in parts of Asia such as Korea, China, and Japan, as well as Europe and North America.{{cite web|url=http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=a645|title=Missouri Botanical Garden}}{{cite journal|last1=Sun-Edelstein|first1=Christina|title=Alternative Headache Treatments: Nutraceuticals, Behavioral and Physical Treatments|journal=Headache|date=March 2011|volume=51|issue=3|pages=469–483|doi=10.1111/j.1526-4610.2011.01846.x|pmid=21352222|s2cid=30412404|doi-access=free}} They prefer moist environments such as riverbanks, marshes and ditches.{{cite journal|last1=Sutherland|first1=Anna|last2=Sweet|first2=Burgunda|title=Butterbur: An alternative therapy for migraine prevention|journal=American Journal of Health-System Pharmacy|date=May 2010|volume=67|issue=9|pages=705–711|doi=10.2146/ajhp090136|pmid=20410544}}[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=124686 Petasites.] Flora of China. Volume 20-21, Page 461. efloras.org.[http://luirig.altervista.org/flora/taxa/gen.php?genere=Petasites Altervista Flora Italiana genere Petasites]

Petasites is closely related to the genera Tussilago and Senecio.

Butterbur has been used for over 2000 years to treat a variety of ailments including fever, lung disease, spasms, and pain. Currently, butterbur extract is used for migraine prevention and treatment of allergic rhinitis, which have the most evidence for its effectiveness.{{cite journal|last1=Kaufeler|first1=Robert|last2=Polasek|first2=Wolfgang|last3=Brattstrom|first3=Axel|last4=Koetter|first4=Uwe|title=Efficacy and Safety of Butterbur Herbal Extract Ze 339 in Seasonal Allergic Rhinitis: Postmarketing Surveillance Study|journal=Advances in Therapy|date=March 2006|volume=23|issue=2|pages=373–384|doi=10.1007/bf02850143|pmid=16751170|s2cid=6597820}}

Some butterbur species contain the chemicals petasin and isopetasin which are believed to have potential benefits in treating migraines. High concentrations of petasin occur in both butterbur root and leaves, with the leaves containing lower levels of the toxic chemical. Butterbur extracts have been reported to be effective in reducing frequency and severity of migraine headaches. Several double-blind studies have shown that high doses of Petasites hybridus extract, containing petasin and/or isopetasin, are effective both in preventing and in relieving migraine, with the best results in groups taking the higher dose of the supplement.{{cite journal |vauthors=Lipton RB, Göbel H, Einhäupl KM, Wilks K, Mauskop A |title=Petasites hybridus root (butterbur) is an effective preventive treatment for migraine |journal=Neurology |volume=63 |issue=12 |pages=2240–4 |date=December 2004 |pmid=15623680 |doi=10.1212/01.wnl.0000147290.68260.11|s2cid=10367187 }} Although mainly well tolerated, the adverse effects of butterbur reported in clinical trials include mainly gastrointestinal problems, such as nausea, flatulence, and belching. In 2015, the American Academy of Neurology withdrew its original endorsement of butterbur due to safety concerns.{{Cite journal|url=https://n.neurology.org/content/78/17/1346|doi=10.1212/WNL.0b013e3182535d0c|title=Evidence-based guideline update: NSAIDs and other complementary treatments for episodic migraine prevention in adults: [RETIRED]|year=2012|last1=Holland|first1=S.|last2=Silberstein|first2=S.D.|last3=Freitag|first3=F.|last4=Dodick|first4=D.W.|last5=Argoff|first5=C.|last6=Ashman|first6=E.|journal=Neurology|volume=78|issue=17|pages=1346–1353|pmid=22529203|pmc=3335449}} However, the Canadian Headache Society still recommends its use in migraine prevention for a selected number of patients based on their clinical features and co-existing disorders.{{cite journal|last1=Pringsheim|first1=Tamara|last2=Davenport|first2=Jeptha|last3=Mackie|first3=Gordon|title=Canadian Headache Society Guideline for Migraine Prophylaxis|journal=Canadian Journal of Neurological Sciences|date=March 2012|volume=39|issue=2|pages=S1–59|pmid=22683887}}

Additionally, a study showed butterbur extract to be an effective treatment for hay fever without the sedative effect of the antihistamine cetirizine, if taken four times daily.Schapowal, A.{{cite journal |author=Schapowal A |date=19 January 2002 |title=Randomised controlled trial of butterbur and cetirizine for treating seasonal allergic rhinitis |journal=BMJ |volume=324 |issue=7330 |pages=144–6 |pmid=11799030 |doi=10.1136/bmj.324.7330.144 |url= |last2=Petasites Study |first2=Group |pmc=64514}} Butterbur was also shown to be comparably effective as fexofenadine when compared to placebo for reducing symptoms of allergic rhinitis.{{cite journal|last1=Schapowal|first1=Andreas|title=Treating Intermittent Allergic Rhinitis: A Prospective, Randomized, Placebo and Antihistamine-controlled Study of Butterbur Extract Ze 339|journal=Phytotherapy Research|date=2005|volume=19|pages=530–537|doi=10.1002/ptr.1705|pmid=16114089|issue=6|s2cid=38128529}}

Butterbur extracts may contain harmful components called pyrrolizidine alkaloids if the preparations are not carefully and fully purified. The concentration of the toxic alkaloids is often highest in the rhizomes and lowest in the leaves, and may vary depending on where the plants are grown.{{cite journal|last1=Taylor|first1=Frederick|title=Nutraceuticals and Headache: The Biological Basis|journal=Headache|date=March 2011|volume=51|issue=3|pages=484–501|doi=10.1111/j.1526-4610.2011.01847.x|pmid=21352223|s2cid=1828681}} These chemicals are toxic to the liver and may cause cancers.Maxim Hirono I., Mori H., Yamada K. "Carcinogenic activity of petasitenine, a new pyrrolizidine alkaloid isolated from Petasites" Journal of the National Cancer Institute 1977 58:4 (1155-1157){{cite journal | pmid = 7017073 | year = 1981 | last1 = Smith | first1 = LW | last2 = Culvenor | first2 = CC | title = Plant sources of hepatotoxic pyrrolizidine alkaloids | volume = 44 | issue = 2 | pages = 129–52 | journal = Journal of Natural Products | doi=10.1021/np50014a001}} Thus, due to the potential for contamination, taking butterbur supplements is not recommended during pregnancy or breastfeeding.{{cite web|title=Butterbur|url=http://online.factsandcomparisons.com/MonoDisp.aspx?monoID=fandc-np5066&quick=237777%7c20&search=237777%7c20&isstemmed=True&NDCmapping=-1&fromTop=true|website=Facts & Comparisons}} Some sources say it is safe practice to consume butterbur extract that has been prepared by a reputable laboratory. Other sources say no butterbur product is safe: "The cases of liver toxicity appear to have occurred with extracts of butterbur where the pyrrolizidine alkaloids had been removed and only small amounts remained. There is some evidence that other constituents found in butterbur such as the sesquiterpene constituents for example petasin may be implicated in the liver toxicity".{{Cite web|url=http://www.raysahelian.com/butterbur.html|title = Butterbur extract supplement benefit, allergy, asthma, and migraine headache}}{{Unreliable source?|date=April 2019}}

Long-term health effects and interaction of butterbur with other drugs have not been well documented. However, it can theoretically interact with certain blood pressure and heart medications, as well as with drugs that can induce a liver enzyme called CYP3A4 (i.e. St. John's wort, carbamazepine, phenytoin, rifampin); this interaction can potentially lead to increased concentration of the toxic alkaloids.

{{Reflist|30em}}

• [http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Petasites&SPECIES_XREF=&TAXON_NAME_XREF=&RANK= Flora Europaea: Petasites species list and distributions]
• [http://www.efloras.org/browse.aspx?flora_id=0&name_str=Petasites eFloras search results: Petasites]
• [http://www.northernbushcraft.com/plants/coltsfoot/notes.htm Edibility of Petasites]: Visual identification and edible parts of sweet coltsfoot.

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Category:Asteraceae genera

Category:Medicinal plants

Category:Taxa named by Philip Miller

Category:Dioecious plants