Potentiation of glucose-induced insulin secretion by fagomine, a pseudo-sugar isolated from mulberry leaves

Horm Metab Res. 1998 Nov;30(11):679-83. doi: 10.1055/s-2007-978957.


The mechanisms of potentiation by fagomine, an N-containing pseudo-sugar derived from mulberry leaves, of insulin secretion from isolated rat pancreatic islets in response to glucose was studied. Fagomine at more than 1 mmol/L significantly potentiated insulin secretion induced by 10 mmol/L glucose. The pseudo-sugar, however, did not affect the basal insulin secretion assessed at a glucose concentration of 3.5 mmol/L. The effects of fagomine on 10 mmol/L and 20 mmol/L glucose-induced insulin secretion were not significantly different. Fagomine (4 mmol/L) also potentiated glyceraldehyde-induced insulin secretion, but not the leucine-induced type. Glycolysis assessed by lactate production from glucose was significantly enhanced. The amounts of all intermediates (from glucose 6-phosphate to glyceraldehyde 3-phosphate) of the upper part of the glycolytic pathway in islets incubated with 20 mmol/L glucose were not affected by 4 mmol/L fagomine. The rise in the ATP/ADP ratio through both the glycolytic pathway and the citric acid cycle is believed to be pivotal in glucose- and glyceraldehyde-induced insulin secretion; whereas the ATP/ADP ratio rise through the citric acid cycle via the formation of acetyl-CoA is involved in leucine-induced insulin secretion. Our findings, together with these considerations, suggest that fagomine potentiates glucose-induced insulin secretion through acceleration of some step(s) after the formation of glyceraldehyde 3-phosphate in the glycolytic pathway.

MeSH terms

  • Acetyl Coenzyme A / metabolism
  • Adenosine Diphosphate / metabolism
  • Adenosine Triphosphate / metabolism
  • Animals
  • Drug Synergism
  • Enzyme Inhibitors*
  • Female
  • Glucose / administration & dosage
  • Glucose / pharmacology*
  • Glyceraldehyde / pharmacology
  • Glyceraldehyde 3-Phosphate / metabolism
  • Glycolysis
  • Imino Pyranoses
  • Insulin / metabolism*
  • Insulin Secretion
  • Islets of Langerhans / drug effects*
  • Islets of Langerhans / metabolism*
  • Lactic Acid / biosynthesis
  • Oligo-1,6-Glucosidase / antagonists & inhibitors
  • Piperidines / administration & dosage
  • Piperidines / pharmacology*
  • Rats
  • Rats, Wistar


  • Enzyme Inhibitors
  • Imino Pyranoses
  • Insulin
  • Piperidines
  • Glyceraldehyde 3-Phosphate
  • Lactic Acid
  • Glyceraldehyde
  • fagomine
  • Adenosine Diphosphate
  • Acetyl Coenzyme A
  • Adenosine Triphosphate
  • Oligo-1,6-Glucosidase
  • Glucose