The crude extract of Swertia chirayita, an important medicinal plant of Nepal, is locally used for many diseases including type 2 diabetes. In this study, crude aqueous and 12% ethanol solution extracts of S. chirayita collected from nine districts of Nepal were analyzed for anti-diabetic-linked anti-hyperglycemia potential using in vitro biochemical assays. There was moderate-to-high positive correlation between antioxidant activity and total phenolic content of both extracts and moderate-to-high α-glucosidase inhibitory activity. Although the anti-diabetic property of S. chirayita is mainly attributed to the phytochemical swerchirin present in its hexane fraction, we propose that the crude extract of this plant used in local healing also has anti-hyperglycemia potential. The crude extracts indicated the presence of three main phytochemicals mainly mangiferin, swertiamarin, and amarogentin and their derivatives. Among the standard compounds (mangiferin, swertiamarin, and amarogentin), mangiferin showed α-glucosidase and 2,2-diphenyl-1-picrylhydrazyl radical inhibitory activity indicating anti-hyperglycemia potential.

Swertia chirayita is an important medicinal plant from Nepal with anti-diabetic, anti-pyretic, antimalarial and anti-inflammatory potential and used in therapeutic herbal preparations in parts of South Asia. The main phytochemicals in crude aqueous and ethanolic extracts of different plant parts of Swertia chirayita collected from nine different districts of Nepal representing West, East and Central Nepal were quantified using HPLC/DAD (High Performance Liquid Chromatography-Diode Array Detection). The quantities of these phytochemicals were also compared between wild and cultivated plant parts of Swertia chirayita. Amarogentin, mangiferin, swertiamarin were the main phytochemicals in all extracts. The highest quantity of all the three phytochemicals was found in IL (inflorescence and leaf mixture) of all the collected plants samples. There was no significant difference in the amounts of these three phytochemicals between extracts from wild and cultivated plants. The result from this study substantiates the validity of cultivated Swertia chirayita for medicinal purposes and trade.

Swertia chirayita (Roxb. ex Fleming) H. Karst is one of the most important high-value medicinal plants of Nepal prized for its anti-diabetic, antimalarial, hepato-protective and anti-inflammatory properties. It is widely used as an important ingredient in medicinal preparations in Ayurveda, Unnani, Siddha, Tibetan and Chinese traditional medicine. Nepal is one of the main exporters of this important plant and the most significant importers are India and China. The large scale export of this plant has made it vulnerable in Nepal and there is an immediate need for its conservation. Detailed information on the current status of trade of this plant in Nepal is necessary to understand and make assumptions on its current market standing or future predictions of demand. S. chirayita is traded in 61 of the 75 districts of Nepal and constituted about 3% in the total medicinal plant traded in the fiscal year 2008-2009. Due to extensive collection of S. chirayita from the wild, there is a need for exploring alternative conservation options in order to preserve the remaining wild population. Sustainable harvesting and cultivation can help in its conservation. This paper briefly reviews the state of trade and sustainable conservation of this important medicinal plant in Nepal. Key words: Swertia chirayita; trade; cultivation; sustainable use; sustainable harvesting DOI: 10.3126/njst.v11i0.4134Nepal Journal of Science and Technology 11 (2010) 125-132

Plants defense responses to abiotic stresses, including salinity stress, involve stimulation of defense related pathways such as biosynthesis of secondary metabolites and induction of endogenous antioxidant enzyme responses. In the present study, a single seed origin clonal line of Swertia chirayita inoculated with Lactobacillus plantarum (LP) was grown under different salinity levels. Control had no LP inoculation. S. chirayita inoculated with LP showed higher accumulation of proline, low proline dehydrogenase activity, up-regulation of pentose phosphate pathway, down-regulation of succinate dehydrogenase activity (Krebs cycle) and low total phenolic content with increased salt concentrations. In comparison, S. chirayita without LP adopted a different biochemical mechanism to counter salt stress (NaCl) by up-regulating both pentose phosphate pathway and Krebs cycle along with stimulation of phenolic biosynthesis. Guaiacol peroxidase (GPX) activity increased with and without LP treatment in response to increasing concentrations of salt. These results indicate that S. chirayita inoculated with LP exhibits a greater salinity stress tolerance than S. chirayita without LP by adopting a more energy efficient defense responses and potentially efficiently partitioning carbon flux between primary and secondary metabolism to counter salt induced oxidative stress.