Insulin-like effect of pinitol

Area of Science:

• Pharmacology
• Endocrinology
• Metabolic Diseases

Background:

• D-pinitol, a compound from Bougainvillea spectabilis, is traditionally used for diabetes.
• It is purported to possess insulin-like properties.
• Its precise mechanism in glucose regulation requires further investigation.

Purpose of the Study:

• To investigate the effects of D-pinitol on glucose homeostasis in animal models of diabetes.
• To examine the impact of D-pinitol on glucose transport in cultured muscle cells.

Main Methods:

• D-pinitol was administered orally and intraperitoneally to normal, obese-diabetic (ob/ob), and streptozotocin (STZ)-diabetic mice.
• Plasma glucose and insulin levels were measured.
• Glucose uptake in L6 rat muscle cells was assessed using 2-deoxyglucose (2DG) uptake assays.
• The role of phosphatidylinositol 3-kinase (PI3K) was evaluated using the inhibitor LY294002.

Main Results:

• D-pinitol acutely reduced hyperglycemia in STZ-diabetic mice by approximately 21-22%.
• Chronic D-pinitol administration maintained reduced plasma glucose levels in STZ-diabetic mice.
• In L6 muscle cells, D-pinitol significantly increased basal glucose uptake, an effect inhibited by LY294002.
• D-pinitol did not affect insulin-stimulated glucose uptake in muscle cells.

Conclusions:

• D-pinitol exhibits insulin-like effects, improving glycemic control in hypoinsulinemic STZ-diabetic mice.
• The mechanism appears to involve a post-receptor pathway influencing glucose uptake in muscle cells.
• D-pinitol shows potential as a therapeutic agent for managing diabetes, particularly in conditions with insulin deficiency.