ARS | Publication request: Development of a Streptozotocin-induced Diabetic Rat Model for Studies on the Effects of Cinnamon on Glucose Tolerance and Insulin Secretion

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 5, 2007
Publication Date: January 5, 2008
Citation: Anderson, R.A., Striffler, J. 2008. Development of a Streptozotocin-induced Diabetic Rat Model for Studies on the Effects of Cinnamon on Glucose Tolerance and Insulin Secretion. Journal of Federation of American Societies for Experimental Biology. 22:1113.6.

Technical Abstract: A streptozotocin (STZ) dose response protocol using graded doses of STZ was utilized to develop a diabetic rat model. In addition to the presence of severe basal hyperglycemia, insulin responses to oral glucose showed no change from basal in rats given more than 45 mg of STZ/kg body wt. Oral glucose tolerance (OGT) in rats given 40 mg of STZ/kg body wt was abnormal but the pancreas was able to secrete significant amounts of insulin. In contrast, there was hyper-secretion of insulin associated with near normalization of glucose tolerance at STZ doses of 20 mg/kg body wt or less. In light of these observations, effects of cinnamon dosing on OGT was characterized in rats made diabetic with 40 mg of STZ/kg body wt. The cinnamon dosing experiments compared OGT and insulin responses in control diabetic rats (n=12) with diabetic rats administered cinnamon (n=12) added directly to the glucose test solution. Over the range of cinnamon levels tested (4 to 400 mg/kg body wt), a cinnamon dose of 65 mg/kg wt) produced the most significant improvements of OGT, which was associated with enhanced insulin secretion. In conclusion, using this chemically diabetic rat model, we have demonstrated that cinnamon can be used to control blood sugar under conditions of impaired glucose tolerance.