Azadirachta excelsa Improves Renal Morphology and Function in Streptozotocin Induced-Diabetic Sprague Dawley Rats

Abstract

Long term diabetes mellitus (DM) is associated with serious complications such as nephropathy. Previous studies revealed the ability of A. excelsa leaf extract treatment to reduce fasting blood glucose (FBG) in streptozotocin (STZ)-induced diabetic rats. The aim of this study was to determine the effect of A. excelsa extract in delaying the progression of diabetic nephropathy by evaluating the kidney structure and function. The effects were compared with 2 positive controls, which were metformin (standard drug) and quercetin (plant active compound). Induction of diabetic conditions was conducted by the intraperitoneal (IP) injection of STZ (60 mg/kg bwt) in male Sprague Dawley rats. The experimental animals were grouped into: 1) normal control (NC, saline); 2) diabetic control (DC, saline); 3) metformin-treated diabetic rats (DMET, 1000 mg/kg bwt); 4) quercetin-treated diabetic rats (DQ, 40 mg/kg bwt), and 5) A. excelsa-treated diabetic rats (DAE, 250 mg/kg bwt). All treatments were given once daily for 8 weeks through oral gavage. The inter-relation between the changes in the fasting blood glucose and kidney oxidative stress, structure, and function was evaluated. The results showed a significant increase (p < 0.05) of MDA and SOD level and a decrease (p < 0.05) of GPx levels, plus distortion of renal morphology among the DC and DMET groups. Meanwhile, both DQ and DAE groups showed significant reduction (p < 0.05) of MDA levels and elevation (p < 0.05) of SOD and GPx levels. The quercetin and A. excelsa treatments also improved the kidney function parameters and morphological changes of the diabetic rats. These findings indicate that quercetin and A. excelsa possess renal therapeutic effects.