EVALUATION OF THE ANTIOXIDANT AND HYPOGLYCEMIC ACTIVITIES OF CURCUMIN IN STZ-INDUCED DIABETIC RATS

Diabetes mellitus is one of the most prevalent chronic metabolic disorders worldwide, characterized by hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Prolonged hyperglycemia is associated with oxidative stress, leading to severe complications such as neuropathy, nephropathy, cardiovascular disease, and retinopathy. Curcumin, the principal bioactive constituent of Curcuma longa, has been widely studied for its antioxidant, anti-inflammatory, and antidiabetic properties. The present study was designed to evaluate the antidiabetic and antioxidant effects of curcumin extract in streptozotocin (STZ)-induced diabetic albino rats. Male Wistar rats were divided into four groups: normal control, diabetic control, and two treatment groups receiving oral curcumin extract at doses of 150 mg/kg and 300 mg/kg, respectively. Diabetes was induced by intraperitoneal administration of STZ at 90 mg/kg body weight for three consecutive days. Biochemical parameters including fasting blood glucose, serum insulin, lipid profile (triglycerides, cholesterol, LDL-C, HDL-C), renal markers (urea, creatinine, microalbumin, total protein), and oxidative stress markers (MDA, SOD, GSH, CAT) were assessed. Histopathological analysis of kidney tissue was also performed. Results revealed significant weight loss, hyperglycemia, dyslipidemia, elevated renal biomarkers, and increased oxidative stress in diabetic control rats compared to normal controls. Curcumin treatment demonstrated a dose-dependent improvement in glycemic control, restoration of lipid profile, reduction in renal biomarkers, and significant enhancement of antioxidant enzyme levels. Histopathological findings confirmed a protective effect of curcumin on renal tissue integrity. In conclusion, curcumin extract exhibited significant antihyperglycemic, antihyperlipidemic, and antioxidant activities in STZ-induced diabetic rats. These findings suggest its therapeutic potential as an adjunctive agent in the management of diabetes and its complications. Further clinical investigations are warranted to overcome curcumin’s bioavailability challenges and to validate its translational relevance in human diabetes management.