Effect of induced diabetes mellius on the histological structure of the renal cortex of adult male albino rats and the possible protective role of licorice extract

ABSTRACT

Diabetes is one of the most common chronic metabolic disorders worldwide. One of the major complications of type 2 diabetes is diabetic nephropathy. The present study was to investigate the effect of type 2 diabetes on the histological structure of the renal cortex of adult male albino rats and the role of licorice ethanolic extract on diabetic renal affection. Forty adult male albino rats were utilized. They were classified into three main groups the control group [group I], the experimental diabetic group [group II], and the possible protected group [group III]. Type 2 diabetes was induced in rats in groups II and III by giving them a high-fat diet and a single low dose of streptozotocin. Diabetic rats were divided into two subgroups untreated subgroup IIa and treated subgroup IIb. The possible protected group received licorice ethanolic extract concomitant with the high-fat diet and the single low dose of streptozotocin. At the end of the experiment, the kidneys were dissected out and processed for light and electron microscopic examination. Fasting blood glucose level, fasting insulin level, serum urea, and creatinine were estimated and statistically analyzed. Examination of the renal cortex of untreated diabetic subgroup IIa demonstrated glomerulosclerosis and distorted podocyte foot processes. The cells lining convoluted tubules revealed thick basement membranes, disorganization of basal infoldings, and mitochondrial disarrangement. The area% of positive Bax immunoreaction was significantly increased in subgroup IIa as compared with subgroup IIb and group III. Examination of the renal cortex of the treated diabetic animals [subgroup IIb] revealed little improvement and failure of licorice extract to normalize renal cortical changes, most probably due to late intervention. In contrast, the protected group [group III] revealed a nearly preserved normal architecture. Changes in the renal cortical structure were attenuated with prophylactic therapy of licorice ethanolic extract