Phytochemical Compositions and Bioactive Properties of <i>Plantago lanceolata</i> L.: Anti-oxidant, Anti-diabetic, and Anti-cholinergic Potentials

In this study, the phenolic compound profile, antioxidant capacity, and inhibition potential on enzymes associated with diseases such as Alzheimer's disease (AD) and diabetes of Plantago lanceolata L. (PL) extract were investigated in detail. Quantitative analysis of phenolic compounds was performed by advanced liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the highest concentration of the phenolic was observed in fumaric acid (4486.80 µg/L). Vanillic acid, kaempferol, resveratrol and caffeic acid were also detected in significant amounts. The antioxidant activities of PL ethanol extract were determined by DPPH, ABTS, FRAP, and CUPRAC methods and revealed moderate radical scavenging and metal-reducing capacities. The PL extract exhibited notable free radical scavenging activity, with inhibition rates of 37.86 ± 2.42% in the DPPH assay and 34.72 ± 2.86% in the ABTS assay. These results revealed that the extract showed an activity close to standard antioxidants such as α-tocopherol. The extract exhibited inhibitory activity against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glucosidase enzymes, with IC₅₀ values of 8.77 ± 0.52, 7.37 ± 0.53, and 3.63 ± 0.27 µg mL-1, respectively. These findings may indicate that PL extract may have therapeutic potential for disorders such as Alzheimer's disease and diabetes.