Antioxidant and alfa-glucosidase inhibitory activity of Achillea tenorii

Context: There is a need for the discovery of novel natural remedies to prevent and treat metabolic disorders such as hyperglycemia, type II non-insulin-dependent diabetes mellitus and obesity. Several Achillea species have been utilized for centuries all around the world and are generally considered effective as hypoglycemic. Objective: Considering the ethnobotanical uses of Achillea genus, we evaluated the in vitro inhibitory activity of Achillea tenorii Grande (Asteraceae) extract on α-glcucosidase, which is a valuable target to prevent and treat metabolic disorders. We also tested its antioxidant activity. Moreover, the phytochemical profile was discussed from a chemotaxonomic point of view. Material and methods: In vitro α-glucosidase inhibition of crude ethanolic extract obtained from the aerial parts was assayed as well as the in vitro antioxidant activity (ABTS, DPPH, and FRAP-FZ tests). The extract was characterized by a phytochemical point of view by means of spectroscopic analysis. Results: The extract results endowed with α-glucosidase inhibitory activity (IC50 32 µg/mL) with a particular mechanism of action definable as un-competitive, which differed from the mechanism observed for the best-known α-glucosidase inhibitor (acarbose and miglitol). In addition, a considerable antioxidant potential has been found for A. tenorii extract, which resulted mainly constituted by phenolic compounds as caffeoylquinic acids, and flavonoids. Discussion and conclusions: These results suggest the potential of A. tenorii as a possible natural remedy to prevent and treat metabolic disorders of carbohydrates