procyanidin-b1 and Diabetes-Mellitus--Type-2

Protein tyrosine phosphatase-1B (PTP1B) is a novel and indispensable drug target for the treatment of type 2 diabetes mellitus (T2DM). Procyanidins are flavonoids that exhibit a significant hypoglycemic function. However, the potential inhibitory effects of procyanidins on PTP1B are unclear. In this study, the interaction mechanisms of PTP1B with procyanidin B1 (PB1) and procyanidin B2 (PB2) were investigated through kinetics analysis, UV-visible spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and molecular docking. The results showed that PB1 and PB2 could inhibit the activity of PTP1B in a mixed inhibition mode, which was one of the reversible inhibition types. Multi-spectral analysis showed that PB1/PB2 formed complexes with PTP1B, which effectively quenched the intrinsic fluorescence of PTP1B based on the static mechanism. The values of the binding constants were K

Topics: Biflavonoids; Catechin; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Humans; Kinetics; Molecular Docking Simulation; Proanthocyanidins; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Spectrum Analysis

Procyanidin oligomers in Cinnamon are thought to be responsible for the biological activity in the treatment of diabetes mellitus (DM). To clarify types of procyanidin oligomers in different Cinnamon species and investigate their different effects, the present study investigated procyanidin oligomers in polyphenolic oligomer-rich extracts of three Cinnamon samples by LC-MS methods, and their hypoglycemic activities were detected in vivo and in vitro. The results showed that two of the three samples from Cinnamomum cassia were rich in B-type procyanidin oligomers, and the other sample was rich in A-type procyanidin oligomers. The Cinnamon extracts were administered at doses of 200 and 300 mg/kg body wt. in high-fat diet-fed and low-dose streptozotocin (STZ)-induced diabetic mice for 14 days. The results showed that blood glucose concentrations were significantly decreased in all Cinnamon extract groups compared with the control group (p<0.05). Administration of the Cinnamon extracts significantly increased the consumption of extracellular glucose in insulin-resistant HepG2 cells and normal HepG2 cells compared with the control group. These results suggest that both A- and B-type procyanidin oligomers in different Cinnamon species have hypoglycemic activities and may improve insulin sensitivity in type 2 DM.

Topics: Animals; Antioxidants; Biflavonoids; Blood Glucose; Catechin; Cinnamomum aromaticum; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Glucose Tolerance Test; Hep G2 Cells; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Male; Mice; Phytotherapy; Plant Bark; Plant Extracts; Plants, Medicinal; Proanthocyanidins; Streptozocin