Molecular docking-guided in-depth investigation of the biological activities and phytochemical and mineral profiles of endemic Phlomis capitata.

Abstract

Background: Phlomis capitata is an endemic species of flowering aromatic and medicinal plant in the family Lamiaceae, native to regions of the Mediterranean and nearby areas. Understanding the chemical compounds present in P. capitata can reveal potential medicinal properties. The present study examines the quantification of bioactive phytochemicals, antioxidant capacity and enzyme inhibitory evaluation of P. capitata extract against key enzymes involved in the pathogenesis of Alzheimer's, diabetes mellitus, epilepsy and glaucoma for the first time. The mechanisms of enzyme inhibition activity of the predominant compounds in extract were also interpreted by molecular docking studies. Chemical characterization of the extract was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (phytochemical profile) and inductively coupled plasma-mass spectrometry (mineral composition) analysis. Furthermore, the binding interactions of major phytochemicals with all enzymes were investigated by molecular docking studies.

Results: LC-MS/MS analysis of the P. capitata revealed the identification of 19 compounds predominated by quinic acid (4.883 mg g^-1), followed by chlorogenic acid (4.36 mg g^-1), vanilic acid (3.405 mg g^-1), naringenin (2.571 mg g^-1) and cyranoside (1.101 mg g^-1). It was determined that the mineral element was rich (K, Ca, Al and Mg) and did not exceed the toxicity limits. The P. capitata extract demonstrated remarkable antioxidant activities in the order: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (IC₅₀: 20.533 μg mL^-1) < 2,2-diphenyl-1-picrylhydrazyl (IC₅₀: 23.151 μg mL^-1) < N,N-dimethyl-p-phenylenediamine (IC₅₀: 45.221 μg mL^-1) and cupric reducing antioxidant capacity (0.889 μg mL^-1) < Fe³⁺ reducing (0.969 μg mL^-1) < ferric reducing antioxidant potency (0.974 μg mL^-1). Moreover, of all the enzyme inhibitory assays (acetylcholinesterase, butyrylcholinesterase, α-amylase, α-glucosidase, and human carbonic anhydrases I and II), the extract showed outstanding inhibitory activities (IC₅₀ values of 3.26, 7.15, 6.15, 6.81, 15.21 and 11.93 μg mL^-1, respectively).

Conclusion: In summary, the findings show that P. capitata is a versatile raw material that can be used in the pharmaceutical, cosmetic and food industries to develop products that promote health. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.