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.

Neopicrorhiza scrophulariiflora (Pennell) Hong: A comprehensive review of its traditional uses, phytochemistry, pharmacology and safety.

ETHNOPHARMACOLOGICAL RELEVANCE: Neopicrorhiza scrophulariiflora (Pennell) Hong is important medicinal plant that is native to the eastern Himalayas and Hengduan mountains in China. It is also distributed in Nepal, north east India, Bhutan and northern Myanmar. Plant parts are traditionally used against different kinds of diseases and various compounds present in different plant parts are also effective against many diseases. Thus, N. scrophulariiflora has a high potential to maintain human health. AIM OF THE REVIEW: Although N. scrophulariiflora is very important and widely studied plant species but there is no comprehensive up-to-date review of published and unpublished literature. So, in the present article we have compiled and critically commented on the botanical characteristics, traditional uses, plant growth and cultivation, micropropagation, conservation status, secondary metabolites, pharmacology and toxicity of the plant. MATERIALS AND METHODS: Extensive literature searches both electronic online databases (Google Scholar, Scopus, Springer Link, Web of Science, ScienceDirect, ResearchGate, PubMed, ChemSpider, USPTO, Google patents and Espacenet) and library visits in Nepal were carried out to collect the literature on information published prior to April 2019. RESULTS: N. scrophulariiflora was traditionally used for 82 ailments/diseases. There are 124 major phytochemicals extracted from the plant. Several compounds are effective in bioactivity. Pharmacologically, the plant is proved to be anti-atherosclerotic, antidiabetic and anti-inflammatory in-vivo studies, and antimicrobial, antimalarial, antioxidative, hepatoprotective, immunomodulatory and nerve growth factor potentiating from in-vitro studies. Renal improvement activities were confirmed from both in-vivo and in-vitro studies. Toxicological tests and a single clinical trial in human beings have supported the notion that the plant is not poisonous but beneficial for curing wide ranges of diseases. CONCLUSION: N. scrophulariiflora is valuable medicinal plant that can serve as promising source of non-harmful and potential medicinal herbal remedies for human beings.