Phlomis armeniaca: Phenolic compounds, enzyme inhibitory and antioxidant activities

This study investigated the phenolic content, enzyme-inhibitory and antioxidant activities of ethyl acetate, methanol and water extracts of Phlomis armeniaca. HPLC analysis showed chlorogenic acid to be the most abundant phytochemical, followed by benzoic acid. Phosphomolybdenum and β-carotene bleaching tests indicated the ethyl acetate extract to have the best activity potential (1.80 mmol trolox equivalents TEs/g extract and 91.50%, respectively); however, the water extract performed best in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radical scavenging tests (125.23 and 43.05 mg TEs/g extract, respectively). Chelating effects and reducing powers of the extracts were also determined. Ethyl acetate extract exhibited considerable enzyme inhibition potential on acetylcholinesterase, butyrylcholinesterase, tyrosinase, α-glucosidase and α-amylase (2.065 mg galantamine equivalents GALAEs/g extract, 4.579 mg GALAEs/g extract, 15.97 mg kojic acid equivalents/g extract, 0.474 mmol acarbose equivalents ACEs/g extract and 2.261 mmol ACEs/g extract, respectively). These findings suggest that P. armeniaca may be useful in the development of an alternative agent for oxidative stress, Alzheimer's disease and diabetes.