細胞学および組織学ジャーナル

Modulation of Pancreatic β-Cells and Antioxidant Status by Cinnamon in Type 2 Diabetic Rats

Abstract

Noor Fatima, Areeba Khaleeq, Shahrukh Momin, Rizwana S Waraich, Saima Khaliq and Rahman M Hafizur

The effect of Cinnamomum cassia was investigated in a non-obese type 2 diabetic rat model to explore possible cellular mechanism(s) of its antidiabetic activity. Non-obese type 2 diabetes was developed in rats by injecting 60 mg/kg streptozotocin (STZ) along with 120 mg/kg nicotinamide (NA) in adult Wistar rats. Type 2 diabetes was confirmed after 14 days of STZ-NA induction. Diabetic rats were treated with cinnamon extract at 250 mg/kg (Cn250) or 500 mg/kg dose (Cn500) and the positive control, glibenclamide (5 mg/kg) for 28 days. After treatment, blood glucose, serum insulin, HbA1c and antioxidant status were measured. Additionally, insulin and glucagon immunostaining was performed in pancreatic sections. Moderate hyperglycemia and β-cells dysfunction was found in this diabetic model rats. Interestingly, cinnamon extract treatment lowered the elevated blood glucose (Cn250: 269.8 ± 18.5 mg/dl vs. 322.5 ± 12.5 mg/dl, p<0.01; Cn500: 195.2 ± 22.5 mg/dl vs. 322.5 ± 12.5 mg/dl, p<0.001) and enhanced serum insulin levels (Cn250: 0.28 ± 0.032 ng/ml vs. 0.195 ± 0.03 ng/ml; Cn500: 0.45 ± 0.035 ng/ml vs. 0.195 ± 0.03 ng/ml, p<0.001) in a dose-dependent manner. In diabetic rats, a drastic decrease of β-cell function was observed while cinnamon extract treatment elevated the β-cell function significantly (p<0.05) in Cn500 treated group. Qualitative and quantitative improvement of pancreatic β-cell morphology was found in cinnamon-treated rats. Total antioxidant status was improved by cinnamon extract suggesting its antioxidant potential in Cn500 dose significantly (1.83 ± 0.05 mmol/L vs. 1.49 ± 0.09 mmol/L, p<0.05). Glibenclamide showed similar action to that of 500 mg/kg cinnamon in all the assays. Collectively, the data suggest that cinnamon exerts antidiabetic activity by increasing insulin secretion, modulating β-cell function, and improving antioxidant status in non-obese type 2 diabetic model rats.