Integrated Pharmacognostic, LC-MS Metabolomic Profiling and Biological Evaluation of Elymus repens (L.) Gould

Abstract

Elymus repens (L.) Gould has a long history of use in traditional medicine across the British Isles, particularly among Gaelic and Anglo-Saxon communities, where it has been employed as a diuretic and anti-inflammatory agent. Despite its ethnopharmacological significance, comprehensive insights into its phytochemical composition and biological activities remain limited. The present study aimed to provide an integrated characterization of E. repens through macro- and microscopic analyses, advanced phytochemical profiling, and evaluation of the biological activities of the rhizome part. Microscopic examination revealed distinct anatomical features differentiating rhizome and stem, leaf tissues, supporting accurate identification and pharmacognostic standardization. Chemical profiling using Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry (LC-QToF-MS) enabled the tentative identification of 93 metabolites, including amino acids, in aerial and rhizome extracts. These compounds were primarily classified into polyamines (e.g., feruloylputrescine, hydroxycoumaroylagmatine), phenolic acids (gallic, vanillic, and ferulic acids), flavonoids (apigenin, tricin, saponarin analogues), amino acids (arginine, tyrosine, tryptophan), organic acids (malic, succinic acids), nucleosides (adenosine, thymidine), and phospholipids. Biological evaluation demonstrated that the hydroethanolic rhizome extract exhibited notable antifungal activity against Aspergillus fumigatus (IC50 = 34.9 µg/mL). Additionally, hydroethanolic extracts of both the aerial and rhizome parts showed no cytotoxicity in the Artemia salina lethality assay at concentrations up to 10 mg/mL, indicating a favorable preliminary safety profile. Of particular interest is tricin, which possesses anti-inflammatory, antioxidant, antimicrobial, and potential nephroprotective therapeutic effects; its mechanism of action is associated with the suppression of oxidative stress, the inhibition of pro-inflammatory mediators, and the disruption of metabolic processes in microbial cells. Overall, this study provides a comprehensive phytochemical and pharmacognostic characterization of E. repens, highlighting its potential as a source of bioactive compounds. The metabolite profile obtained directly from the biologically active extract, combined with its proven antifungal activity, serves as direct confirmation of the antimicrobial aspect of this plant’s traditional use, while its broader applications in ethnomedicine require targeted pharmacological testing. These findings contribute valuable data for chemotaxonomic classification and future pharmacological investigations.