Thuja occidentalis L. (Cupressaceae): Ethnobotany, Phytochemistry and Biological Activity

Thuja occidentalis L. (Cupressaceae) has its origins in Eastern North America and is cultivated in Europe and Brazil as an ornamental tree, being known as the “tree of life” or “white cedar”. In traditional medicine, it is commonly used to treat liver diseases, bullous bronchitis, psoriasis, enuresis, amenorrhea, cystitis, uterine carcinomas, diarrhea, and rheumatism. The chemical constituents of T. occidentalis have been of research interest for decades, due to their contents of essential oil, coumarins, flavonoids, tannins, and proanthocyanidines. Pharmacology includes antioxidant, anti-inflammatory, antibacterial, antifungal, anticancer, antiviral, protective activity of the gastrointestinal tract, radioprotection, antipyretic, and lipid metabolism regulatory activity. Therefore, the present review represents the synthesis of all the relevant information for T. occidentalis, its ethnobotany, phytochemistry, and a thorough analysis of their pharmacological activities, in order to promote all the biological activities shown so far, rather than the antitumor activity that has promoted it as a medicinal species.