A review of traditional use, phytoconstituents and biological activities of Himalayan yew, Taxus wallichiana.

Plants synthesize certain phytoconstituents for their protection, which, because they are not of primary need, are known as secondary metabolites. These secondary metabolites of plants, have often been found to have medicinal uses for human beings. One such gymnosperm having secondary metabolites of medicinal potential for humans is Taxus wallichiana (Himalayan yew). Besides being the source of taxol, this plant has been investigated for its essential oil, diterpenoids, lignans, steroids, sterols and biflavonoids. Traditionally, it is used to treat disorders of the digestive, respiratory, nervous and skeletal systems. Although pharmacologically underexplored, it has been used for antiepileptic, anti-inflammatory, anticancer, antipyretic, analgesic, immunomodulatory and antimicrobial activities. The present review compiles traditional uses, phytochemical constituents (specifically the secondary metabolites) pharmacological activities and the toxicity of T. wallichiana.