Antioxidant and α-glucosidase inhibitory activities of Achillea tenorii

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.

Considering the ethnobotanical uses of Achillea genus, we evaluated the in vitro inhibitory activity of Achillea tenorii Grande (Asteraceae) extract on α-glucosidase, 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.

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) was measured. The extract was characterized from a phytochemical point of view by means of spectroscopic analysis.

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 such as caffeoylquinic acids and flavonoids.

These results suggest the potential of A. tenorii as a possible natural remedy to prevent and treat metabolic disorders of carbohydrates.