Novel Liver-targeted conjugates of Glycogen Phosphorylase Inhibitor PSN-357 for the Treatment of Diabetes: Design, Synthesis, Pharmacokinetic and Pharmacological Evaluations

Sci Rep. 2017 Feb 22:7:42251. doi: 10.1038/srep42251.

Abstract

PSN-357, an effective glycogen phosphorylase (GP) inhibitor for the treatment for type 2 diabetics, is hampered in its clinical use by the poor selectivity between the GP isoforms in liver and in skeletal muscle. In this study, by the introduction of cholic acid, 9 novel potent and liver-targeted conjugates of PSN-357 were obtained. Among these conjugates, conjugate 6 exhibited slight GP inhibitory activity (IC50 = 31.17 μM), good cellular efficacy (IC50 = 13.39 μM) and suitable stability under various conditions. The distribution and pharmacokinetic studies revealed that conjugate 6 could redistribute from plasma to liver resulting in a considerable higher exposure of PSN-357 metabolizing from 6 in liver (AUCliver/AUCplasma ratio was 18.74) vs that of PSN-357 (AUCliver/AUCplasma ratio was 10.06). In the in vivo animal study of hypoglycemia under the same dose of 50 mg/kg, conjugate 6 exhibited a small but significant hypoglycemic effects in longer-acting manners, that the hypoglycemic effects of 6 is somewhat weaker than PSN-357 from administration up to 6 h, and then became higher than PSN-357 for the rest time of the test. Those results indicate that the liver-targeted glycogen phosphorylase inhibitor may hold utility in the treatment of type 2 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Intravenous
  • Animals
  • Body Fluids / chemistry
  • Cholic Acid / chemistry
  • Cholic Acid / therapeutic use*
  • Diabetes Mellitus, Experimental / drug therapy*
  • Diabetes Mellitus, Experimental / metabolism
  • Enzyme Assays
  • Glycogen Phosphorylase / antagonists & inhibitors*
  • Glycogen Phosphorylase / metabolism
  • Glycogenolysis
  • Hep G2 Cells
  • Humans
  • Inhibitory Concentration 50
  • Liver / metabolism*
  • Mice
  • Microsomes, Liver / metabolism
  • Piperidines / chemistry
  • Piperidines / therapeutic use*
  • Rabbits
  • Structure-Activity Relationship
  • Time Factors
  • Tissue Distribution

Substances

  • Piperidines
  • Glycogen Phosphorylase
  • Cholic Acid