The hypoglycaemic activity of fenugreek seed extract is mediated through the stimulation of an insulin signalling pathway

Abstract

1 The in vivo hypoglycaemic activity of a dialysed fenugreek seed extract (FSE) was studied in alloxan (AXN)-induced diabetic mice and found to be comparable to that of insulin (1.5 U kg À1). FSE also improved intraperitoneal glucose tolerance in normal mice. 2 The mechanism by which FSE attenuated hyperglycaemia was investigated in vitro. FSE stimulated glucose uptake in CHO-HIRc-mycGLUT4eGFP cells in a dose-dependent manner. This effect was shown to be mediated by the translocation of glucose transporter 4 (GLUT4) from the intracellular space to the plasma membrane. 3 These effects of FSE on GLUT4 translocation and glucose uptake were inhibited by wortmannin, a phosphatidylinositol 3-kinase (PI3-K) inhibitor, and bisindolylmaleimide 1, a protein kinase C (PKC)-specific inhibitor. 4 In vitro phosphorylation analysis revealed that, like insulin, FSE also induces tyrosine phosphorylation of a number of proteins including the insulin receptor, insulin receptor substrate 1 and p85 subunit of PI3-K, in both 3T3-L1 adipocytes and human hepatoma cells, HepG2. However, unlike insulin, FSE had no effect on protein kinase B (Akt) activation. 5 These results suggest that in vivo the hypoglycaemic effect of FSE is mediated, at least in part, by the activation of an insulin signalling pathway in adipocytes and liver cells.

Effects of Oil Palm (Elais guineensis) Fruit Extracts on Glucose Uptake Activity of Muscle, Adipose and Liver Cells

“…This activation subsequently enhanced tyrosine phosphorylation of insulin receptor substrate-1 (IrS-1) and p85 subunit of phosphatidylinositol-3-kinase (PI3-kinase) which leads to glucose uptake by these cells (Vijayakumar et al 2005). The insulin sensitizing activity has…”

Chamaemelum nobile L. Aqueous Extract Represses Endogenous Glucose Production and Improves Insulin Sensitivity in Streptozotocin-induced Diabetic Mice

“…Consequently, the results of the present study suggest that CN administration could improve insulin sensitivity in peripheral tissues. Many herbal preparations and medicinal plants have been reported to possess similar insulin sensitizing activities both in experimental study and clinical investigations, Indigofera mysorensis [32] , Gymnema sylvestre [30] , Panax ginseng [33][34] , Trigonella foenum-graecum [35] , Sanguis draxonis [36] and Acanthopanax senticosus [37] , Gasha-jinki-gan [38][39][40] and dietary Guar gum [41] . Improvement of peripheral insulin sensitivity may be a consequence of the stimulation of insulin signalling pathway [39,42] .…”

To study the efficacy and tolerability of fenugreek seed powder as add-on therapy with metformin in patients of type-2 diabetes mellitus

“…In an experiment conducted by Vijayakumara et al alloxan was given intraperitoneally to albino mice. 17 The active principle responsible for antihyperglycemic activity is largely due to fenugreeks saponins, high fibre content, the amino acid hydroxyisoleucine and the major alkaloid trigonelline. Anti-hyperglycemic effect was due to stimulation of insulin secretion and delayed gastric emptying caused by high fibre content, inhibiting carbohydrate enzymes.…”