Inhibition of protein tyrosine phosphatase 1B by lignans from Myristica fragrans

Abstract

Inhibition of protein tyrosine phosphatase 1B (PTP1B) has been proposed as one of the drug targets for treating type 2 diabetes and obesity. Bioassay-guided fractionation of a MeOH extract of the semen of Myristica fragrans Houtt. (Myristicaceae) afforded PTP1B inhibitory compounds, meso-dihydroguaiaretic acid (1) and otobaphenol (2). Compounds 1 and 2 inhibited PTP1B with IC50 values of 19.6 ± 03 and 48.9 ± 0.5 μM, respectively, in the manner of non-competitive inhibitors. Treatment with compound 1 on 32D cells overexpressing the insulin receptor (IR) resulted in a dose-dependent increase in the tyrosine phosphorylation of IR. These results indicate that compound 1 can act as an enhancing agent in intracellular insulin signaling, possibly through the inhibition of PTP1B activity.