Protein Tyrosine Phosphatase 1B Inhibitory Activity of Amentoflavone and Its Cellular Effect on Tyrosine Phosphorylation of Insulin Receptors

• Published in: Biological & Pharmaceutical Bulletin Vol. 30; no. 2; pp. 379 - 381
• Main Authors: Na, MinKyun, Kim, Kyung Ah, Oh, Hyuncheol, Kim, Bo Yeon, Oh, Won Keun, Ahn, Jong Seog
• Format: Journal Article
• Language: English
• Published: Japan The Pharmaceutical Society of Japan 01-02-2007; Pharmaceutical Society of Japan; Japan Science and Technology Agency
• Subjects: amentoflavone; Biflavonoids - pharmacology; Dual Specificity Phosphatase 3; non-competitive inhibitor; Phosphoprotein Phosphatases - metabolism; Phosphorylation; protein tyrosine phosphatase 1B; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatases - antagonists & inhibitors; Protein Tyrosine Phosphatases - metabolism; Receptor, Insulin - metabolism; Selaginella tamariscina; Selaginellaceae; Tyrosine - metabolism; tyrosine phosphorylation of insulin receptor
• ISSN: 0918-6158; 1347-5215
• DOI: 10.1248/bpb.30.379

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 μM. Kinetic study suggested that amentoflavone is a non-competitive inhibitor of PTP1B, with a Ki value of 5.2 μM. 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.