Anti-diabetic effect of sorghum extract on hepatic gluconeogenesis of streptozotocin-induced diabetic rats

Abstract

Background: It has been suggested that Sorghum, a rich source of phytochemicals, has a hypoglycemic effect, but the mechanism is unknown. We investigated the effects of oral administration of sorghum extract (SE) on hepatic gluconeogenesis and the glucose uptake of muscle in streptozotocin- induced diabetic rats for six weeks. Methods. Male Wistar rats were divided in five groups (n=5 per group): normal control (NC), rats with STZ-induced diabetic mellitus (DM), diabetic rats administrated 0.4 g/kg body weight of SE (DM-SE 0.4) and 0.6 g/kg body weight of SE (DM-SE 0.6), and diabetic rats administrated 0.7 mg/kg body weight of glibenclamide (DM-G). Results: Administration of SE and G reduced the concentration of triglycerides, total and LDL-cholesterol and glucose, and the area under the curve of glucose during intraperitoneal glucose tolerance tests down to the levels observed in non-diabetic rats. In addition, administration of 0.4 and 0.6 g/kg SE and 0.7 mg/kg glibenclamide (G) significantly reduced the expression of phosphoenolpyruvate carboxykinase and the phosphor-p38/p38 ratio, while increased phosphor adenosine monophosphate activated protein kinase (AMPK)/AMPK ratio, but the glucose transporter 4 translocation and the phosphor-Akt/Akt ratio was significantly increased only by administration of G. Conclusions: These results indicate that the hypoglycemic effect of SE was related to hepatic gluconeogenesis but not the glucose uptake of skeletal muscle, and the effect was similar to that of anti-diabetic medication. © 2012 Kim and Park; licensee BioMed Central Ltd.