Steviol glycosides, primarily stevioside and rebaudioside A, are natural constituents of the plant Stevia rebaudiana Bertoni. Steviosides are already in use as non-caloric sweeteners (1). Several studies have reported hypoglycemic effects of Stevia extracts, particularly among individuals affected by type 2 diabetes, a disease associated to impaired insulin secretion and insulin resistance in peripheral tissues, leading to hypoinsulinemia and hyperglycemia (2). The aim of this study was to investigate the effect of rebaudioside A and three different mixtures of steviol glycosides on the regulation of glucose uptake in different cell types and their ability in activating a signaling cascade similar to insulin pathway. The effect of four Stevia extracts on glucose transport activity was evaluated in HL-60 human leukaemia cells, expressing principally the basal glucose transporter (GLUT)1, and in SHSY-5Y human neuroblastoma cells, expressing also GLUT4, the insulin sensitive one (3). The influence of Stevia extracts on glucose transport activity was compared to the effect of insulin and of methylglyoxal, inhibitor of the insulin receptor/PI3K/Akt pathway. The treatment with insulin or steviol glicosides causes similar effects on the glucose uptake. The concomitant treatment with insulin and Stevia extracts causes a rise of glucose transport higher than the increase due to insulin and steviol glicosides alone. Methylglyoxal incubation induces a significant decrease in glucose transport and the subsequent treatment with Stevia extracts (and insulin) is able to raise the glucose uptake. Taken together these results corroborate the hypothesis that Stevia extracts could mimic insulin effects on glucose uptake modulating PI3K/Akt pathway.
|Titolo:||Steviol extracts are able to modulate glucose transport in two different cell types|
|Data di pubblicazione:||2013|
|Appare nelle tipologie:||Abstract atto convegno su volume|