Antioxidant potential, enzyme inhibition activity, and phenolic profile of extracts from Stachys cretica subsp. vacillans

Mediterranean Woundwort (Stachys cretica L. subsp. vacillans Rech. Fil.) belongs to Turkish flora with limited distribution in south-west of the country. The objective of this study was to analyze the antioxidant and enzyme inhibition activities, and phenolic profiles of the aerial parts of this plant using methanol and water as solvents. The results demonstrated that methanol was most efficient for polyphenols and flavonoids' extraction. Using LC-ESI-MS analysis, 24 and 22 compounds were identified respectively in methanolic and water extracts. Six compounds were predominant in both extracts; chlorogenic acid, vanillic acid, syringic acid, verbascoside, apigenin 7-glucoside, and apigenin. Also, the antioxidant capacities tested with five methods revealed strong activities with significant differences among solvents. Both extracts were active against the two enzymes (aamylase and tyrosinase), except the aqueous extract against a-amylase. Also, the enzyme inhibition activities were significantly higher in methanol than in water extract. The current results support the therapeutic traditional uses of Stachys cretica subsp. vacillans and its potential as source of natural bioactive compounds The latter need more chemical screening using other solvents and organs in order to identify new natural antioxidant and key enzyme inhibitor molecules from this species.