Aucklandia costus (syn. Saussurea costus): Ethnopharmacology of an endangered medicinal plant of the Himalayan region

Ethnopharmacological relevance: Aucklandia costus Falc. a medicinal plant is native to the Himalayan region and synonymous with Saussurea costus, Saussurea lappa, and Aucklandia lappa. It has an ancient background of being used ethnopharmacologically for various body ailments. According to Ayurveda, Unani, Siddha, and Traditional Chinese Medicine, Costus roots are recommended for leukoderma, liver, kidney, blood disorders, Qi stagnation, and tridosha. Root and powder are used orally with warm water to cure gastric problems, and the paste is applied to the inflamed area to relieve pain. Root paste is applied on the skin to cure boils, blisters, and leprosy.

Aim of the study: The aim of the present review is to establish a correlation among the ethnopharmacological uses and scientific studies conducted on A. costus with chemical constituents, safety & toxicity data including future directions for its conservation with higher yield and effect.

Materials and methods: The study was conducted by studying books, research papers, and literature in history, agroforestry, phytopharmacology of Himalayan plants using international databases, publication, Red data book, and reports. The search engines: Pubmed, Scopus, Wiley Inter-science, Indian Materia Medica, Science Direct, and referred journals are referenced.

Results: The literature collected from databases, journals, websites, and books mentioned the use of costus roots in local and traditional practices. CITES included A. costus in a critically endangered category due to lack of cultural practices and overexploitation from wild. A. costus roots are known since 13^th century for use in ancient Ayurvedic products but the scientific evaluation is of future research interest. A correlation of traditional uses with scientific studies has been explored to assess the effect of root powder, extract, oil and isolated constituents: Costunolids, Saussureamine B and Dehydrocostus lactone etc. in gastric ulceration and lesions; inhibition of antigen-induced degranulation, mucin production, number of immune cells, eosinophils, and expression and secretion of Th2 cytokines (IL-4 and IL-13) in asthma. The inhibition of pro-inflammatory mediators is also reported by Cynaropicrin, Alantolactone, Caryophyllene, Costic acid. Also, the sesquiterpene lactones has profound effect in inhibition of inflammatory stages and induced apoptotic cascades in cancer. Very few data on the safety and toxicity of plant parts have been noted which needs to be evaluated scientifically.

Conclusion: A. costus have been noted to have remarkable effect for gastric, hepatic, inflammatory, respiratory, cancer, skin problems but there were several errors in selection of plant material, authentification, selection of dose, assessment, selection of standard and control have been identified. Therefore, a schematic drug development and research strategy exploiting the potential of plant extract, fraction, products and probable constituents, costunolide, dehydrocostus lactone, cynaropicrin, saussureamine assuring dose-response relationship and safety may be determined under pre-clinical which may be extrapolated to clinical level. An evaluation of phytochemicals in A. costus collected from different geographical location in Himalayas may be drawn to identify and conserve the higher yielding plant.

Keywords: Aucklandia; Conservation; Critically Endangered; Ethnopharmacology; Himalayan; Saussurea.