Potential Therapeutic Effect of Curcuma longa on Streptozotocin Induced Diabetic rats

Azza A. El-Masry

Department of Zoology, Faculty of Science, Alexandria University, Egypt.

E-mail: ahssan555@yahoo.com

Accepted 18 May, 2012

Abstract

There is increasing evidence that complications related to diabetes are associated with increased oxidative stress. Curcuma longa has several biological properties, including antioxidant activity. The protective effect of Curcuma longa on streptozotocin (STZ)-induced oxidative stress in various tissues of rats was studied. Adult male albino Wister rats (8 weeks), weighing 195 to 225 g was made diabetic by injecting STZ (65 mg/kg body weight) intraperitoneally. During the whole experimental period, animals were fed with a balanced commercial chow and water ad libitum. Diabetic rats given either water or ethanolic extracts of the active material "curcumin" gained by crushing Curcuma longa rhizomes (80 mg/kg body weight) in aqueous suspension daily using an intragastric tube for a period of seven weeks. After this period the levels of oxidative stress parameters and activity of antioxidant enzymes were determined in various tissues. STZ-induced hyperglycemia resulted in increased glucose level, glycosylated haemoglobin in red blood cells and other tissues and altered antioxidant enzyme activities such as AST and ALT. These elevated blood parameters and enzymatic activities induced by hyperglycemia were significantly restored to near normal by oral administration of curcumin once daily for 7 weeks, as compared to untreated rats. There was a significant elevation in the level of liver and kidney malondialdhyde (MDA), while the activities of antioxidant enzymes superoxide dismutase and catalase (SOD and CAT) were significantly decreased in STZ rats which also restored to normal after curcumin treatment. The results obtained indicated that ethanolic extract has more potent protective action than water extract against all hyperglycemic parameters. These biochemical observations showing that feeding curcumin to the diabetic rats controlled oxidative stress by inhibiting the increase in TBARS and protein carbonyls and reversing altered antioxidant enzyme activities without altering the hyperglycemic state in most of the tissues. Curcumin appear to be beneficial in preventing diabetes-induced oxidative stress in rats despite unaltered hyperglycemic status.

Keywords:  Diabetes mellitus; Streptozotocin; Curcuma longa; Therapeutic effects; Rats.