Effect of cinnamon aqueous extracts on hyperglycemia in diabetes-induced wistar rat model

Diabetes mellitus is considered the epidemic of the century. Although various treatments for diabetes are available, the development of effective novel treatments based on medicinal plants is not yet recognized. Therefore, this study focused on the ability of Cinnamomum verum to lower blood glucose levels in Wistar rats suffering from diabetes. The cinnamon bark extract was prepared by sonication in water for one hour. Wistar rats (weight 180-220 g) were kept alternately in the dark and the light for 12 hours, with a standard diet and constant water supply. Diabetes was induced with streptozotocin (STZ), and the diabetic rats were divided into groups (6 rats/group), which were treated with cinnamon and metformin for 42 days. Fasting blood glucose levels were measured at regular intervals. After 42 days, the rats were sacrificed, and blood was collected by cardiac puncture to measure fasting blood glucose (FBG), insulin, lipid profile, renal function, and liver function tests. In the cinnamon-treated group, the mean FBG (IQR) at baseline and four weeks after treatment were 310 (256 -352) mg/dL and 119 (105-147) mg/dL, respectively (p = 0.02). However, no significant difference in insulin resistance and lipid profile was observed. The biochemical tests, hematological analysis, and histopathological examinations showed that the 42-day treatment with cinnamon had no significant adverse effects on kidney, liver, and bone marrow function. It can be concluded that the aqueous cinnamon bark extracts effectively improve hyperglycemia without adversely affecting the liver, kidneys, or bone marrow.