Myo-inositol inhibits intestinal glucose absorption and promotes muscle glucose uptake: a dual approach study

J Physiol Biochem. 2016 Dec;72(4):791-801. doi: 10.1007/s13105-016-0517-1. Epub 2016 Sep 6.

Abstract

The present study investigated the effects of myo-inositol on muscle glucose uptake and intestinal glucose absorption ex vivo as well as in normal and type 2 diabetes model of rats. In ex vivo study, both intestinal glucose absorption and muscle glucose uptake were studied in isolated rat jejunum and psoas muscle respectively in the presence of increasing concentrations (2.5 % to 20 %) of myo-inositol. In the in vivo study, the effect of a single bolus dose (1 g/kg bw) of oral myo-inositol on intestinal glucose absorption, blood glucose, gastric emptying and digesta transit was investigated in normal and type 2 diabetic rats after 1 h of co-administration with 2 g/kg bw glucose, when phenol red was used as a recovery marker. Myo-inositol inhibited intestinal glucose absorption (IC50 = 28.23 ± 6.01 %) and increased muscle glucose uptake, with (GU50 = 2.68 ± 0.75 %) or without (GU50 = 8.61 ± 0.55 %) insulin. Additionally, oral myo-inositol not only inhibited duodenal glucose absorption and reduced blood glucose increase, but also delayed gastric emptying and accelerated digesta transit in both normal and diabetic animals. Results of this study suggest that dietary myo-inositol inhibits intestinal glucose absorption both in ex vivo and in normal or diabetic rats and also promotes muscle glucose uptake in ex vivo condition. Hence, myo-inositol may be further investigated as a possible anti-hyperglycaemic dietary supplement for diabetic foods and food products.

Keywords: Intestinal glucose absorption; Muscle glucose uptake; Myo-inositol; Rats; Type 2 diabetes.

MeSH terms

  • Administration, Oral
  • Animals
  • Biological Transport / drug effects
  • Blood Glucose / metabolism*
  • Carbohydrate Metabolism / drug effects
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / diet therapy*
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Experimental / pathology
  • Diabetes Mellitus, Type 2 / metabolism
  • Diabetes Mellitus, Type 2 / pathology
  • Dietary Supplements
  • Dose-Response Relationship, Drug
  • Hyperglycemia / diet therapy*
  • Hyperglycemia / metabolism
  • Hyperglycemia / pathology
  • Hypoglycemic Agents / pharmacology*
  • Inositol / pharmacology*
  • Insulin / metabolism
  • Intestinal Absorption / drug effects*
  • Jejunum / drug effects
  • Jejunum / metabolism
  • Male
  • Psoas Muscles / drug effects*
  • Psoas Muscles / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Streptozocin
  • Tissue Culture Techniques

Substances

  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin
  • Inositol
  • Streptozocin