CURCUMIN, THE ACTIVE PRINCIPLE OF TURMERIC (CURCUMA LONGA), AMELIORATES DIABETIC NEPHROPATHY IN RATS

Diabetes was induced by a single intraperitoneal injection of STZ (65 mg/kg) in rats. Four weeks after STZ injection, rats were divided into four groups, namely control rats, diabetic rats and diabetic rats treated with curcumin (15 and 30 mg/kg, p.o.) for 2 weeks. Renal function was assessed by creatinine, blood urea nitrogen, creatinine and urea clearance and urine albumin excretion. Oxidative stress was measured by renal malonaldehyde, reduced glutathione and the anti‐oxidant enzymes superoxide dismutase and catalase.

Streptozotocin‐injected rats showed significant increases in blood glucose, polyuria and a decrease in bodyweight compared with age‐matched control rats. After 6 weeks, diabetic rats also exhibited renal dysfunction, as evidenced by reduced creatinine and urea clearance and proteinuria, along with a marked increase in oxidative stress, as determined by lipid peroxidation and activities of key anti‐oxidant enzymes. Chronic treatment with curcumin significantly attenuated both renal dysfunction and oxidative stress in diabetic rats.

These results provide confirmatory evidence of oxidative stress in diabetic nephropathy and point towards the possible anti‐oxidative mechanism being responsible for the nephroprotective action of curcumin.