THUJA OCCIDENTALIS L. (CUPRESSACEAE): REVIEW OF BOTANICAL, PHYTO-CHEMICAL, PHARMACOLOGICAL AND TOXICOLOGICAL ASPECTS

Thuja occidentalis called the tree of life is an endemic plant in eastern North America and cultivated in northern Europe and in Brazil as ornamental tree. According to the popular use of this plant has been used in herbal and homeopathic preparations for acute and chronic infections of the upper respiratory tract, warts, as adjunctive antibiotic, immunostimulant. However, these and other data are old or unavailable, and in view of the therapeutic potential of the species, it was necessary to upgrade the recently published studies and not included in previous reviews about the botanical, pharmacological, toxicological and technological aspects.  In this review article, it was noted that for many years the phytochemistry studies on the species concentrated their efforts around essential oils, highlighting the monoterpene thujone, which is attributed to the pharmacological and toxicological activities. Recently, preclinical studies have identified the presence of polysaccharides, flavonoids, tannins and proteins in the ethanol fraction, which showed antioxidant, hepatoprotective, antitumor, hypolipidemic, antidiabetic and antiulcerative activity. The clinical studies proving its immunostimulant and action against warts, however no need to isolate the constituents responsible for the therapeutic action and to establish of quality parameters for plant drug and its derivatives, capable of ensuring the effectiveness, safety and quality of products from T. occidentalis.