Investigation of antihyperglycemic potentials of seven Centaurea L. species through in vitro studies and characterization of possible bioactive phenolics by LC–MS/MS and molecular docking approach

The taxon Centaurea L., a natural wealth with a high endemism rate in Türkiye, has been traditionally used in treating diabetes. This study aimed to determine the diabetes-associated biological activities and phytochemical content of different solvent extracts of Centaurea benedicta (L.) L, C. cariensis Boiss. subsp. microlepis (Boiss.) Wagenitz, C. drabifolia Sm. subsp. cappadocica (DC.) Wagenitz, C. iberica Trev. ex. Sprengel, C. solstitialis L. subsp. solstitialis, C. urvillei DC. subsp. stepposa Wagenitz, and C. virgata Lam. via in vitro and in silico methods. The antihyperglycemic potentials were estimated by determining the extracts’ α-amylase, α-glucosidase, and DPP-4 enzyme inhibitory abilities. The antioxidant capacities along with the total phenolic and flavonoid contents of the plant extracts were estimated by various methods. An LC-MS/MS analysis was used for the quantitative determination of the phytochemical components of the active extracts. In silico docking approach pointed out possible substances accounting for biological activity. Evaluating the α-glucosidase inhibitory activity of the plant extracts, the methanol and ethyl acetate extracts of C. urvillei were identified as the most active plant extracts with the lowest IC₅₀ values on α-glucosidase (17.9 and 17.6 µg/mL, respectively). None of the tested extracts inhibited α-amylase and DPP-4. The most abundant compounds in the active extracts were achieved by the LC-MS/MS method. Among those, cosmosiin and cynaroside were identified as promising antihyperglycemic agents based on molecular docking studies, suggesting their potential accounting for α-glucosidase inhibitory activity. Alcoholic and hydroalcoholic plant extracts generally exerted high antioxidant capacity. To conclude, specifically C. urvillei extracts along with cosmosiin and cynaroside were determined as potential and promising antihyperglycemic agents. The traditional usage of Centaurea species was verified, leading to the design of forthcoming projects associated with the antihyperglycemic potential of Centaurea species.