Comprehensive Analysis of the Antioxidant and Enzyme Inhibitory Properties and Phenolic Compounds of Phlomis armeniaca: Potential Applicant in Neurodegenerative Diseases

This study investigates the antioxidant and enzyme inhibitory properties of Phlomis armeniaca, a perennial plant native to the eastern and southeastern regions of Turkey. Ethanol extracts of the plant were analyzed using various bioanalytical methods, including Fe3⁺-Fe2⁺ reducing power, Cupric Reducing Antioxidant Capacity, 1,1-diphenyl-2-picryl-hydrazyl (DPPH), and 2,2-azinobis 3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging activities, as well as total phenolic and flavonoid content assessments. The results showed that P. armeniaca is rich in phenolic (38.75 ± 0.59 µg gallic acid equivalents/mg extract) and flavonoid compounds (39.34 ± 4.08 µg quercetin equivalents/mg extract). The plant demonstrated significant inhibitory effects on acetylcholinesterase (half-maximal inhibitory concentration [IC50]: 45.00 ± 0.48 mg/mL) and butyrylcholinesterase (IC50: 84.51 ± 0.84 mg/mL) enzymes, indicating its potential use in treating neurodegenerative diseases such as Alzheimer's. The study also highlighted P. armeniaca’s high chlorogenic acid, salicylic acid, 4-dihydroxybenzoic acid, and quinic acid contents, supporting its antioxidant capacity. These findings suggest that P. armeniaca could be a valuable natural resource for developing therapeutic agents to manage oxidative stress and related conditions, warranting further pharmacological exploration.