Antidiabetic activity of some pentacyclic acid triterpenoids, role of PTP–1B: In vitro, in silico, and in vivo approaches

Abstract

The aim of the current study was to investigate the oral antidiabetic activity of four structurally-related triterpenic acids: ursolic (RE-01), oleanolic (RE-02), moronic (RE-03) and morolic (RE-04) acids. STZ-nicotinamide diabetic rats were treated with these triterpenes (50 mg/kg) and the antidiabetic effects in acute experiment were determined. All compounds showed significant antidiabetic activity in comparison with control group (p < 0.05). The in vitro inhibitory activity of compounds against protein tyrosine phosphatase 1B (PTP–1B) was also evaluated. At 50 μM, the enzymatic activity was almost completely inhibited. All compounds were docked with a crystal structure of PTP–1B. Docking results suggested the potential binding of the triterpenic acids in a binding pocket next to the catalytic site. An extensive hydrogen bond network with the carboxyl group and Van der Waals interactions stabilize the protein-ligand complexes.