Phenolic ingredients and therapeutic potential of Stachys cretica subsp. smyrnaea for the management of oxidative stress, Alzheimer’s disease, hyperglycemia, and melasma

Abstract Woundwort plants ( Stachys species) are used traditionally as food additives, herbal tea, and medicine. At this work, antioxidant activity of S. cretica subsp. smyrnaea was comprehensively investigated using 6 different methods together with phenolic profile and total phenolics/flavonoids content of its several extracts. Moreover, key enzymes inhibitory potential of the herb associated with Alzheimer’s disease, hyperglycemia, and hyperpigmentation was evaluated. Promising antiradical activity (1.9–17.3 mg Trolox equivalents/g dry plant) and metal ion reducing power (4.6–14.6 mg Trolox equivalents/g dry plant) was recorded. Also, S. cretica manifested strong antityrosinase (2.45 mg kojic acid equivalent/g dry plant) and extraordinary anti-amylase and anti-glucosidase (6–61 and 14–47 mg acarbose equivalent/g dry plant, respectively) effects. Reverse phase high performance liquid chromatography analysis identified 12 phenolic compounds of them, chlorogenic acid, hesperidin, kaempferol, apigenin, and benzoic acid were the most abundant (426, 407, 390, 216, and 188 μg/g dry plant, respectively). Findings indicated that, S. cretica has great potential for possible applications in cosmeceutical, pharmaceutical, and food industries.