Intestinal α-Glucosidase Inhibitors in Achillea millefolium

Achillea millefolium is a plant used as a component of anti-diabetic preparation but the bioactive compounds responsible for its use are not known. Inhibition of intestinal α-glucosidase is a preferable effect for prevention and treatment of diabetes, and A. millefolium extract showed inhibitory activity against the enzyme. Activity-guided separation of the extract gave four mono- or di-caffeoylquinic acids as the isolate. Quantitation of these four caffeoylquinic acids and the activity of the isolates suggested that these are the major contributor for the α-glucosidase inhibitory activity in the extract. However also, the presence of unidentified, minor, but potent α-glucosidase inhibitor in the isolate was also suggested