Coniferous, pyramidal evergreen tree, Thuja occidentalis L., Cupressaceae, used as an ornamental plant and in traditional medicine to treat respiratory infection, warts, scurvy and rheumatism. Habit. North America, Europe. Medicinal portions include the dried, leafy young branches and the oil extracted from the leaves and branch tips. Constit. Volatile oil (1.4-4%); p-coumaric acid; umbelliferone; flavonoids incl. quercetin, mearusitrin; tannic acid (≈1.3%); polysaccharides and proteins (≈4%). Botanical description and medicinal uses: J. Gruenwald et al., PDR for Herbal Medicines (Medical Economics, Montvale, 2nd Ed., 2000) pp 759-760. Review of pharmacology and clinical experience: B. Naser et al., Evid. Based Complement. Alternat. Med. 2, 69-78 (2005).
Constit. α-thujone (69%), β-thujone (7-10%), fenchone (10-15%). Fragrance monograph: Food Cosmet. Toxicol. 12, 843-844 (1974).
Immunostimulant.