Petasites japonicus (Petasites japonicus): Benefits, Dosage, Safety & Evidence

Questions fréquentes

How does Petasites japonicus work to relieve coughs and spasms?

Petasites japonicus exerts its effects primarily through compounds called petasins, specifically petasin and furanopetasin. These sesquiterpenes are believed to inhibit leukotriene synthesis and block calcium channels in smooth muscle cells, leading to antispasmodic and anti-inflammatory effects. By relaxing bronchial smooth muscles, the plant helps reduce airway constriction and the urge to cough. While this mechanism is well-documented in related butterbur species, specific clinical trials for Petasites japonicus are limited (Evidence Level: C).

Does Petasites japonicus interact with prescription medications?

Yes, Petasites japonicus carries significant interaction risks, particularly regarding liver function. Because raw plant material contains toxic pyrrolizidine alkaloids (PAs), it should never be combined with hepatotoxic drugs like acetaminophen or certain antibiotics, as this increases the risk of liver damage. Additionally, its potential antispasmodic effects may theoretically interfere with bronchodilator medications. To ensure safety, consumers must use only certified PA-free extracts and consult a physician before use (Evidence Level: C).

What is the safe dosage for Petasites japonicus?

For culinary use, young stalks (known as fuki) are consumed as a vegetable after blanching to remove bitterness. For medicinal purposes, such as pain or cough relief, there is no standardized dosage due to limited clinical data. Crucially, medicinal products must be certified PA-free (free of pyrrolizidine alkaloids) to prevent liver toxicity. Users should strictly follow manufacturer guidelines for PA-free extracts, as raw or homemade preparations are unsafe for therapeutic dosing (Evidence Level: C).

Is Petasites japonicus safe to take during pregnancy?

No, Petasites japonicus is unsafe during pregnancy and breastfeeding. The plant naturally contains pyrrolizidine alkaloids (PAs), which are hepatotoxic and have been linked to veno-occlusive disease. These compounds can cross the placenta and may harm fetal development. Even PA-free extracts are generally advised against during pregnancy due to insufficient safety data. Pregnant women should avoid this herb entirely and seek alternative remedies for cough or pain (Evidence Level: D).

What are the side effects of eating Japanese butterbur?

When prepared correctly as a food, Japanese butterbur (fuki) is generally safe; however, consuming raw or unprocessed plant parts poses serious health risks. The primary side effect is liver toxicity caused by pyrrolizidine alkaloids (PAs), which can lead to liver damage or veno-occlusive disease. Symptoms may include abdominal pain, jaundice, and fatigue. To avoid these side effects, only young stalks should be eaten after proper cooking, and medicinal extracts must be verified PA-free (Evidence Level: C).

Fiche d'information compilée à partir de PubMed

Cette fiche a été compilée à partir de résumés PubMed (NIH) avec l'assistance d'une IA. Chaque affirmation factuelle est citée par un article PubMed réel (voir la liste des sources). Elle n'a pas encore été révisée par un humain — confirmez auprès d'un professionnel de santé avant utilisation.

Compilé à partir de 30 articles PubMed · modèle : gemma4:31b

Résumé

Petasites japonicus is a plant of the Asteraceae family used in traditional East Asian medicine for treating allergies, inflammation, and headaches [PMID:32801463, 26674157, 32532086].

Contexte

Petasites japonicus, also known as Japanese butterbur, is an edible and medicinal plant native to East Asia [PMID:32801463, 35051554, 34603606].

Usages traditionnels

The roots and stems have been used in Japan and Korea for the prophylaxis or treatment of tension headaches and migraines [PMID:32801463]. It is also used in traditional Korean, Japanese, and Chinese medicine to treat asthma and allergic diseases [PMID:26674157, 28566621].

Composés actifs

Key components include sesquiterpenoids (such as petasin), lignans (including petasitesins A and B), flavonoids (such as quercetin glucosides, kaempferol, and rutin), and pyrrolizidine alkaloids (including neopetasitenine and petasitenine) [PMID:32801463, 30784002, 31795455, 35051554, 12224645, 37107470].

Mécanisme d'action

Mechanisms include the inhibition of iNOS and COX-2 to reduce PGE2 and NO production [PMID:31795455], suppression of the PPAR-gamma pathway to inhibit adipogenesis [PMID:31282906, 35051554], and inhibition of bacterial neuraminidase (NA) [PMID:32532086]. It also exhibits antioxidant activity by enhancing glutathione levels and enzyme activities like GPx and GST [PMID:20828319].

Preuves cliniques

Preuve DAllergy/Asthma

Petatewalide B from P. japonicus leaves showed anti-allergic and anti-inflammatory effects in an ovalbumin-induced asthma model [PMID:26674157]

Preuve DObesity/Lipid Profile

Extracts reduced body weight gain, fat accumulation in the liver, and improved total cholesterol and triacylglycerol levels in diet-induced obesity mice [PMID:37107470, 20828319]

Preuve DNeuroinflammation/Alzheimer's-like pathology

Leaf extract (KP-1) reduced NO production and iNOS protein levels in LPS-induced microgliosis and amyloid beta oligomer models [PMID:36193798]

Preuve DMalaria

Ethanolic extract exhibited antimalarial activities in vitro and in vivo by inhibiting platelet activation [PMID:35598522]

Preuve DHIV-1 Replication

Water extract strongly inhibited DNA polymerase and RNase H activities of HIV-1 reverse transcriptase and inhibited replication in human cells [PMID:25663480]

Sécurité et effets indésirables

Case reports indicate the potential for anaphylaxis to Japanese butterbur scapes [PMID:27451267, 34169585]. In male rats, leaf powder (5%) increased hepatic oxidative stress and relative liver weight [PMID:23132561]. Long-term administration (13 weeks) in rats led to hyperkeratosis and squamous cell hyperplasia of the stomach limiting ridge [PMID:34441739].

Synthèse des preuves

The current evidence is primarily based on in vitro assays and animal models (Level D), with limited case reports on allergic reactions. No human clinical trials (RCTs) were provided in the source abstracts.

Sources PubMed

1.PMID: 23132561 (2012) — Japanese butterbur (Petasites japonicus) leaves increase hepatic oxidative stress in male rats. · Bioscience, biotechnology, and biochemistry
2.PMID: 32801463 (2020) — Antioxidant compounds of Petasites japonicus and their preventive effects in chronic diseases: a review. · Journal of clinical biochemistry and nutrition
3.PMID: 27451267 (2017) — Anaphylaxis to Japanese butterbur scapes. · Allergology international : official journal of the Japanese Society of Allergology
4.PMID: 35598522 (2022) — Petasites japonicus extract exerts anti-malarial effects by inhibiting platelet activation. · Phytomedicine : international journal of phytotherapy and phytopharmacology
5.PMID: 30784002 (2019) — New otonecine-type pyrrolizidine alkaloid from Petasites japonicus.

Petasites japonicus

Sources et citations

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