title: Protein tyrosine phosphatase 1B inhibitory activity of amentoflavone and its cellular effect on tyrosine phosphorylation of insulin receptors.
abstract: Inhibition of protein tyrosine phosphatase 1B (PTP1B) has been proposed as a strategy for the treatment of type 2 diabetes and obesity. Bioassay-guided fractionation of MeOH extract of Selaginella tamariscina (Selaginellaceae) afforded a PTP1B inhibitory compound, amentoflavone. The compound inhibited PTP1B with an IC50 value of 7.3+/-0.5 microM. Kinetic study suggested that amentoflavone is a non-competitive inhibitor of PTP1B, with a Ki value of 5.2 microM. Treatment of 32D cells overexpressing the insulin receptor (IR) with amentoflavone resulted in a dose-dependent increase in tyrosine phosphorylation of IR. These results indicate that amentoflavone may enhance insulin-induced intracellular signaling possibly through inhibition of PTP1B activity.
authors.affiliation: Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.
authors.forename: MinKyun
authors.initials: M
authors.lastname: Na
authors.forename: Kyung Ah
authors.initials: KA
authors.lastname: Kim
authors.forename: Hyuncheol
authors.initials: H
authors.lastname: Oh
authors.forename: Bo Yeon
authors.initials: BY
authors.lastname: Kim
authors.forename: Won Keun
authors.initials: WK
authors.lastname: Oh
authors.forename: Jong Seog
authors.initials: JS
authors.lastname: Ahn
mesh_terms: D044946:Biflavonoids / Q000494:pharmacology*; D054640:Dual Specificity Phosphatase 3; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011972:Receptor, Insulin / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D044946:Biflavonoids; D014443:Tyrosine; C011164:amentoflavone; D011972:Receptor, Insulin; D010749:Phosphoprotein Phosphatases; D054640:Dual Specificity Phosphatase 3; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D017027:Protein Tyrosine Phosphatases