Thuja plicata (Thuja plicata): Benefits, Dosage, Safety & Evidence

Questions fréquentes

How does Thuja plicata work as an antiviral and immune stimulant?

Thuja plicata contains thujone, terpenes, flavonoids, and tannins that contribute to its biological activity. The thujone and other terpenes exhibit antiviral properties and appear to stimulate immune cell function. These compounds may enhance immune response and inhibit viral replication. Traditional use by Pacific Northwest First Nations peoples supports these applications, though clinical evidence remains limited (Evidence Level C).

Is Thuja plicata safe during pregnancy and breastfeeding?

Thuja plicata is contraindicated during pregnancy and breastfeeding. The thujone content poses significant risks, including potential neurotoxicity and uterine stimulation, which may lead to miscarriage or harm to fetal development. Women who are pregnant, trying to conceive, or breastfeeding should avoid all Thuja preparations, including topical applications. Consult a qualified healthcare provider for safe alternatives.

What is the recommended dosage for Thuja plicata tincture?

The typical adult dosage for Thuja plicata tincture is 0.5-1ml daily, taken in small divided doses. Due to thujone content and potential neurotoxicity, higher doses should be strictly avoided. Short-term use is recommended, and treatment should not exceed 2-3 weeks without professional guidance. Always consult a qualified herbalist or healthcare provider for personalized dosing recommendations.

Does Thuja plicata interact with any medications?

Thuja plicata may interact with anticonvulsant medications, as thujone can lower seizure thresholds. It may potentiate the effects of other CNS-active substances and should not be combined with alcohol or sedatives. Patients taking immunosuppressants should exercise caution, as Thuja may stimulate immune activity and reduce drug efficacy. Always consult a healthcare provider before combining with prescription medications.

Can Thuja plicata be used topically for wart removal?

Thuja plicata has been traditionally used by Pacific Northwest First Nations peoples for wart removal. Topical applications of Thuja tincture or oil may help treat common and plantar warts due to antiviral and keratolytic properties. Apply sparingly to the affected area 1-2 times daily, avoiding healthy skin. Evidence is primarily traditional (Evidence Level C). Discontinue if irritation occurs.

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

Thuja plicata (Western red cedar) is a coniferous tree whose essential oil shows potential antimicrobial and anti-inflammatory effects in vitro [PMID:22408584, 29450142], but its wood dust is a known cause of occupational asthma [PMID:766943, 3074282].

Contexte

Thuja plicata, also known as Western red cedar or Arborvitae, is a coniferous tree native to North America [PMID:15741156, 40202932].

Composés actifs

The wood contains plicatic acid, a low-molecular-weight compound identified as the agent responsible for inducing asthma [PMID:3074282, 6768786, 8116639].

Mécanisme d'action

Plicatic acid may induce asthma through the activation of the classical complement pathway [PMID:6768786] and by triggering histamine release from basophils [PMID:8116639]. Arborvitae essential oil (AEO) has been shown to inhibit the expression of inflammation-related proteins (VCAM-1, ICAM-1, IP-10, I-TAC, MIG, and M-CSF) and tissue remodeling proteins (collagen-I, collagen-III, PAI-1, TIMP-1, and TIMP-2) in human dermal fibroblasts [PMID:29450142].

Preuves cliniques

Preuve COccupational Asthma

Inhalation of Thuja plicata dust causes occupational asthma and rhinitis; symptoms often occur hours after exposure and may persist for years after avoidance [PMID:3074282, 5448121, 3571771].

Preuve DEnvironmental Decontamination

Cedar leaf oil (CLO) demonstrated broad-spectrum antimicrobial activity against various Gram-positive and Gram-negative bacteria and fungi in vitro [PMID:22408584].

Preuve DCervical Cancer (In Vitro)

Arborvitae essential oil was screened for cytotoxic properties and influence on gene expression in HeLa and SiHa cervical cancer cell lines [PMID:39229997].

Sécurité et effets indésirables

Occupational exposure to Thuja plicata dust can lead to asthma and rhinitis [PMID:5448121]. In some cases, asthma persists indefinitely even after exposure is avoided [PMID:3074282].

Synthèse des preuves

The evidence consists primarily of occupational health reviews and case reports regarding respiratory sensitization (Level C) and preliminary in vitro laboratory studies on essential oils (Level D).

Sources PubMed

1.PMID: 766943 (1976) — Occupational asthma. · Canadian Medical Association journal
2.PMID: 3074282 (1988) — Occupational asthma. · Postgraduate medical journal
3.PMID: 39229997 (2024) — Effects of Arborvitae (Thuja plicata) Essential Oil on Cervical Cancer Cells: Insights into Molecular Mechanisms. · Anti-cancer agents in medicinal chemistry
4.PMID: 40202932 (2025) — Western red cedar (Thuja plicata) beehives have no impact on honey bee (Apis mellifera) overwintering colony survival or detoxification enzyme expression. · PloS one
5.PMID: 36875860 (2023) — Pest categorisation of Urocerus albicornis. · EFSA journal. European Food Safety Authority
6.

Thuja plicata

Sources et citations

Calculer une dose sûre de Thuja plicata

Corchorus Olitorius

Oyster Mushroom

Acanthopanax Sessiliflorus

Questions fréquentes

Résumé

Contexte

Composés actifs

Mécanisme d'action

Preuves cliniques

Sécurité et effets indésirables

Synthèse des preuves

Sources PubMed

Sources gouvernementales

Thuja plicata

Sources et citations

Calculer une dose sûre de Thuja plicata

Plantes associées

Corchorus Olitorius

Oyster Mushroom

Acanthopanax Sessiliflorus

Questions fréquentes

Résumé

Contexte

Composés actifs

Mécanisme d'action

Preuves cliniques

Sécurité et effets indésirables

Synthèse des preuves

Sources PubMed

Sources gouvernementales