Phenolic profile, antioxidant and enzyme inhibitory properties of phenolic-rich fractions from the aerial parts of Mentha pulegium L.

This study investigated into the phenolic profile and biological properties of Mentha pulegium L. based on the antioxidant and enzyme inhibitory activities. Total phenolic and flavonoid contents were spectrophotometrically quantified. The phenolic profile was analyzed by RP-HPLC-PDA. Galvinoxyl radical (GOR), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing activity, cupric reducing and β-carotene bleaching methods were performed to evaluate antioxidant potential. Enzyme inhibitory activity was tested towards alpha-glucosidase, alpha-amylase, acetylcholinesterase and butyrylcholinesterase. The results indicated that ethyl acetate fraction exhibited the strongest antioxidant potential with its higher phenolic and flavonoid contents. This fraction also exerted the highest alpha-glucosidase (IC50 of 61.85 ± 1.69 μg/mL), alpha-amylase (IC50 of 16.37 ± 0.11 μg/mL), AChE (IC50 of 3.13 ± 0.05 μg/mL) and BChE (IC50 of 12.97 ± 0.20 μg/mL) inhibitory activities, its activity was higher than that of acarbose and galantamine used as standard drugs. Gallic acid, p-coumaric acid, ferulic acid, naringenin and quercetin were identified in this fraction. Hence, these findings suggest that M. pulegium is a promising source of bioactive compounds, which could be helpful in the management of oxidative stress associated diseases including diabetes and Alzheimer's disease.