The effect of Cinnamomum cassia extract on oxidative stress in the liver and kidney of STZ-induced diabetic rats.

OBJECTIVES: Many diabetes-related complications are caused by oxidative stress. In the current study, the protective effect of Cinnamomum cassia against diabetes-induced liver and kidney oxidative stress was evaluated. METHODS: The male Wistar rats (n=48) were randomly divided into six groups including; control group received 500 µL normal saline orally for 42 days. Diabetes groups received intraperitoneally (i.p.) streptozotocin (STZ) as single-dose (60 mg/kg, i.p.). Cinnamon extract (100, 200, 400 mg/kg) and metformin (300 mg/kg) were orally administered to diabetic rats for 42 days. After the experiment period, the animals were anesthetized and the liver and kidney tissues were quickly removed and restored for oxidative stress evaluation. The levels of malondialdehyde (MDA), total thiol content, glutathione (GSH), nitric oxide (NO) metabolites, as well as, superoxide dismutase (SOD) and catalase (CAT) activities were measured in kidney and liver tissue. RESULTS: The level of MDA, SOD, and CAT activities increased significantly, while the total thiol content, and NO production were significantly reduced in diabetic animals compared to the control group (from p<0.05 to p<0.001). Treatment with cinnamon extract significantly decreased the MDA level, as well as, SOD and CAT activities in the liver and kidney of diabetic rats (from p<0.05 to p<0.001). In the liver and kidney of cinnamon treated groups, GSH and total thiol contents and NO production were significantly higher than diabetic group (from p<0.05 to p<0.001). CONCLUSIONS: Cinnamon extract due to its potent antioxidant property could be effective in decrease of diabetes-induced oxidative stress that plays a major role in renal and hepatic complications.