Abstract

Diabetes mellitus (DM) is diagnosed by the presence of hyperglycemia, which leads to increased oxidative stress. In this study, we aimed to determine whether cinnamon and sugar tea extract have protective effects on streptozotocin (STZ)+nicotinamide-induced diabetic rats. The therapeutic potential of cinnamon and tea extract on DM was assessed through analysis of their effects on both oxidative stress and DNA damage. Seventy-eight Sprague Dawley rats were divided into nine groups, including control groups, untreated diabetic group, and treated diabetic groups. Diabetes was induced by intraperitoneal administration of STZ and nicotinamide. Cinnamon and sugar tea extracts were administered to diabetic treatment groups for 30 days after diabetes was induced. At the end of the experiment, tissue and blood samples were taken from all rats. The levels of glutathione peroxidase, superoxide dismutase, catalase and malondialdehyde were determined in the liver homogenate. Comet assay was used to assess DNA damage in blood cells. DNA damage as assessed by comet length was increased in diabetic groups and decreased in cinnamon and sugar tea treated groups relative to controls. Our study revealed that treatment with either cinnamon or sugar tea extract has protective effects against oxidative stress in type II diabetic rats.

Key words: Comet assay, antioxidant enzymes, cinnamon, streptozotocin-nicotinamide (STZ-NA), induced diabetes.