Protein tyrosine phosphatase 1B inhibitory activity of anthraguinones and stilbenes

Abstract

Protein tyrosine phosphatase IB (PTP1B) is emerging as a potential therapeutic target for the treatment of type-2 diabetes and obesity. To search for new types of FTP1B inhibitors, we have undertaken in vitro enzyme assay for some anthraquinones and stilbenes isolated from plants. of the anthraquinones tested, physcion (1), 1-O-methylemodin (2), and emodin (3) showed high activities, with IC50 values of 7.6, 7.0, and 3.8 μg/mL, respectively, while the anthraquinone glycosides, physcion-8-O-β-D- glucopyranoside (4) and emodin-8-O-(3-D-glucopyranoside (5), were less active than their aglycones. All the stilbenens (6 -15) slightly inhibited PTP1B activity at high concentration of 30 μg/mL. Our findings suggest that the hypoglycemic effect of anthraquinones may be associated with their PTP1B inhibitory activity.