Effects of the soluble fiber complex PolyGlycopleX® (PGX®) on glycemic control, insulin secretion, and GLP-1 levels in Zucker diabetic rats

Life Sci. 2011 Feb 28;88(9-10):392-9. doi: 10.1016/j.lfs.2010.11.014. Epub 2010 Nov 30.

Abstract

Aims: The effects of the novel water soluble, viscous fiber complex PolyGlycopleX® [(α-D-glucurono-α-D-manno-β-D-manno-β-D-gluco), (α-L-gulurono-β-D mannurono), β-D-gluco-β-D-mannan (PGX®)] on body weight, food consumption, glucose, insulin, and glucagon-like peptide (GLP-1) levels were determined in Zucker diabetic rats (ZDFs). Such fibers are thought to improve glycemic control through increased GLP-1 induced insulin secretion.

Main methods: ZDFs were treated 12 weeks with normal rodent chow supplemented with cellulose (control, inert fiber), inulin or PGX® at 5% wt/wt and effects on body weight, glycemic control, and GLP-1 determined.

Key findings: In the fed state, PGX® reduced blood glucose compared to the other groups from week 5 until study termination while insulin was significantly elevated when measured at week 9, suggesting an insulin secretagogue effect. Fasting blood glucose was similar among groups until 7-8 weeks when levels began to climb with a modest reduction caused by PGX®. An oral glucose tolerance test in fasted animals (week 11) showed no change in insulin sensitivity scores among diets, suggesting an insulinotropic effect for PGX® rather than increased insulin sensitivity. PGX® increased plasma levels of GLP-1, while HbA(1c) was markedly reduced by PGX®. Body weights were not changed despite a significant reduction in food consumption induced by PGX® up to week 8 when the PGX®-treated group showed an increase in body weight despite a continued reduction in food consumption.

Significance: PGX® improved glycemic control and reduced protein glycation, most likely due to the insulin secretagogue effects of increased GLP-1.

MeSH terms

  • Alginates / administration & dosage*
  • Animal Feed
  • Animals
  • Blood Glucose / metabolism*
  • Body Weight / drug effects
  • Cellulose / administration & dosage
  • Diabetes Mellitus, Type 2 / blood*
  • Drug Combinations
  • Eating / drug effects
  • Glucagon-Like Peptide 1 / blood*
  • Glucose Tolerance Test
  • Glycated Hemoglobin / metabolism
  • Hyperglycemia / blood
  • Hyperglycemia / diet therapy*
  • Insulin / blood*
  • Male
  • Polysaccharides, Bacterial / administration & dosage*
  • Rats
  • Rats, Zucker

Substances

  • Alginates
  • Blood Glucose
  • Drug Combinations
  • Glycated Hemoglobin A
  • Insulin
  • PolyGlycoplex
  • Polysaccharides, Bacterial
  • Glucagon-Like Peptide 1
  • Cellulose