Advances in Ethnobotany, Synthetic Phytochemistry and Pharmacology of Endangered Herb Picrorhiza kurroa (Kutki): A Comprehensive Review (2010-2020)

Picrorhiza kurroa Royle ex Benth. (Family: Plantaginaceae) is a well-recognized Ayurvedic herb. It is commonly called "Kutki" or "Kurro" and 'Indian gentian'. Iridoid glycosides are the plant's bioactive constituents accountable for the bitter taste and medicinal properties of the plant. The iridoid glycosides such as picrosides and other active metabolites of the plant exhibit many pharmacological activities like hepatoprotective, antioxidant, anti-inflammatory, anticancer, immunomodulator, anti-ulcerative colitis, antimicrobial, etc. This review aims to provide updated information on the ethnobotany, synthetic phytochemistry, pharmacological potential, safety and toxicology of P. kurroa and its active metabolites. Indiscriminate exploitation, ecological destruction of natural habitats, slower plant growth and unawareness regarding cultivation and uprooting of plants have brought kutki an endangered status. Therefore, various techniques used for the conservation and production of bioactive metabolites from P. kurroa have also been reported. Information on the plant has been collected from Science Direct, Google Scholar, PubMed, Scopus using 'Picrorhiza kurroa', 'Picroside-', 'Picroside-II', 'Picroliv', 'Immunomodulator' keywords. All studies on ethnobotany, phytochemistry and pharmacology of plant from 2010- 2020 were comprised in this review article. The possible directions for future research have also been outlined briefly in this review article.