Effect of Cichorium intybus L. seed extract on renal parameters in experimentally induced early and late diabetes type 2 in rats

Blood and urine biochemistry screening tests are important for initial detection of diabetes, determination of severity of its complications, and monitoring of therapy. We evaluated the effects of aqueous chicory seed extract (CSE), on renal biochemical parameters, histology, and Na+/glucose cotansporters, SGLT1 and SGLT2 expression levels using metformin, and aspirin as controls. Late stage type 2 diabetes (LT2D; FBS, >300 mg/dl) and early stage type 2 diabetes (ET2D; FBS, 140–220 mg/dl) were induced in rats by streptozotocin (STZ group) and a combination of STZ and niacinamide (NIA/STZ group), respectively. A non-diabetic group was included as control. Treatment included daily intraperitoneal injections of either CSE (125 mg/kg b.w.) or metformin (100 mg/kg b.w.) and oral aspirin (120 mg/kg b.w.) for 21 days. At the end, blood and 24 h urine samples were collected; and kidneys were saved at −80 ˚C. CSE reduced urinary α1-microgobulin excretion in ET2D (p = .043), and serum uric acid (p = .045), and glomerular diameter (p < .01) in LT2D. Metformin appeared to be more effective in LT2D with respect to serum uric acid, urea, and BUN (< .05). Both CSE and metformin improved histology. Aspirin improved several blood and urine variables, but appeared to aggravate morphological damages to the kidney tissue. The absolute values of albumin, α1-microglobulin or total protein in urine rather than their creatinine ratios seemed more useful in the detection of early kidney damage; CSE was able to repair the kidney damage and α1-microglobulin was sensitive enough to allow monitoring of the improvements caused by the treatment.