Article date: August 2000
By: Sarah H Bates, Robert B Jones, Clifford J Bailey in Volume 130, Issue 8, pages 1944-1948
D‐pinitol (3‐O‐methyl‐chiroinositol), an active principle of the traditional antidiabetic plant Bougainvillea spectabilis, is claimed to exert insulin‐like effects. This study investigates the effect of D‐pinitol on glucose homeostasis in animal models of diabetes, and on glucose transport by cultured muscle cells.
Plasma glucose concentrations were measured in normal, obese‐diabetic (ob/ob) and streptozotocin (STZ)‐diabetic mice after oral (p.o.) and intraperitoneal (i.p.) administration of D‐pinitol. Glucose transport was measured in L6 rat muscle cells by 2‐deoxyglucose (2DG) uptake.
In STZ‐diabetic mice, 100 mg kg−1 p.o. D‐pinitol acutely decreased the hyperglycaemia (by 22% at 6 h). A similar decrease in plasma glucose (by 21%) was observed after 100 mg kg−1 i.p. D‐pinitol. Insulin concentrations and the rate of insulin‐induced (1 unit kg−1 actrapid i.p.) glucose disappearance were not altered by 100 mg kg−1 p.o. D‐pinitol. Chronic administration of D‐pinitol (100 mg kg−1 i.p. twice daily for 11 days) to STZ‐diabetic mice maintained a reduction in plasma glucose concentrations from about 14 to 10 mmol l−1.
In normal non‐diabetic and severely insulin resistant ob/ob mice, 100 mg kg−1 p.o. D‐pinitol did not significantly affect plasma glucose or insulin during acute studies.
Incubation of L6 muscle cells with D‐pinitol (10−3 M) increased basal 2DG uptake by 41% after 10 min and by 34% after 4 h. The effect of D‐pinitol was inhibited by the phosphatidylinositol 3‐kinase inhibitor LY294002. D‐pinitol did not increase insulin‐stimulated 2DG uptake by L6 cells.
The data support the view that D‐pinitol can exert an insulin‐like effect to improve glycaemic control in hypoinsulinaemic STZ‐diabetic mice. D‐pinitol may act via a post‐receptor pathway of insulin action affecting glucose uptake.
D‐pinitol (3‐O‐methyl‐chiroinositol), an active principle of the traditional antidiabetic plant Bougainvillea spectabilis, is claimed to exert insulin‐like effects. This study investigates the effect of D‐pinitol on glucose homeostasis in animal models of diabetes, and on glucose transport by cultured muscle cells.
Plasma glucose concentrations were measured in normal, obese‐diabetic (ob/ob) and streptozotocin (STZ)‐diabetic mice after oral (p.o.) and intraperitoneal (i.p.) administration of D‐pinitol. Glucose transport was measured in L6 rat muscle cells by 2‐deoxyglucose (2DG) uptake.
In STZ‐diabetic mice, 100 mg kg−1 p.o. D‐pinitol acutely decreased the hyperglycaemia (by 22% at 6 h). A similar decrease in plasma glucose (by 21%) was observed after 100 mg kg−1 i.p. D‐pinitol. Insulin concentrations and the rate of insulin‐induced (1 unit kg−1 actrapid i.p.) glucose disappearance were not altered by 100 mg kg−1 p.o. D‐pinitol. Chronic administration of D‐pinitol (100 mg kg−1 i.p. twice daily for 11 days) to STZ‐diabetic mice maintained a reduction in plasma glucose concentrations from about 14 to 10 mmol l−1.
In normal non‐diabetic and severely insulin resistant ob/ob mice, 100 mg kg−1 p.o. D‐pinitol did not significantly affect plasma glucose or insulin during acute studies.
Incubation of L6 muscle cells with D‐pinitol (10−3 M) increased basal 2DG uptake by 41% after 10 min and by 34% after 4 h. The effect of D‐pinitol was inhibited by the phosphatidylinositol 3‐kinase inhibitor LY294002. D‐pinitol did not increase insulin‐stimulated 2DG uptake by L6 cells.
The data support the view that D‐pinitol can exert an insulin‐like effect to improve glycaemic control in hypoinsulinaemic STZ‐diabetic mice. D‐pinitol may act via a post‐receptor pathway of insulin action affecting glucose uptake.
British Journal of Pharmacology (2000) 130, 1944–1948; doi:10.1038/sj.bjp.0703523
DOI: 10.1038/sj.bjp.0703523
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