The effect of flaxseed ethanolic extract on the structure and functions of the kidney and the endocrine pancreas in streptozotocin induced diabetic rats

Abstract

Diabetes-induced oxidative stress is strongly associated with both micro- vascular and macro-vascular complications, including nephropathy. Flaxseed contains many biologically active substances; it is the richest source of lignans, which have antioxidant activity. The present investigation has been designed to study the possible protective effect of flaxseed extract on the structures and functions of the endocrine pancreas and kidneys of streptozotocin (STZ) induced diabetic rats for 30 days. Forty male Sprague-Dawley rats were randomized into five groups (n=8). Normal control group (NC); received distilled water orally, normal flaxseed group (NF); treated orally with (400 mg/kg) extract of flaxseed, diabetic control group (DC); treated with single intraperitoneal dose of STZ (60 mg/kg), diabetic flaxseed group (DF); diabetic rats treated with extract of flaxseed (400 mg/kg), diabetic glibenclamide group (DG); diabetic rats treated with (0.6 mg/kg) glibenclamide. Fasting blood glucose level, body weight, relative kidney weight, blood urea level, serum creatinine level and histopathological changes of the endocrine pancreas and kidneys were examined in all experimental rats. Biochemical observation revealed a significant increment (p<0.05) in fasting blood glucose level, relative kidney weight, blood urea level and serum creatinine level with significant decrement (p<0.05) in body weight in DC group in comparison with the NC group. These changes were improved in both DF and DG groups, however the improvement was only significant (p<0.05) in DG group. Histological observation of sections in pancreas in DC group revealed shrunken islets of Langerhans with degenerated and degranulated ?-cells, vacuolations, hyaline deposition and congested capillaries while sections of kidneys showed shrinkage of some glomeruli and degeneration of others with wide urinary space and hydropic degeneration in some tubular epithelial cells, dilated tubules and cell debris scattered in tubular lumina. These pathological changes were ameliorated in the flaxseed extract and glibenclamide treated rats. It is concluded that ethanolic extract of flaxseed might have a promising beneficial effect on D.M.