Effect of Costus pictus per se and in combination with Metformin and Enalapril in streptozotocin induced diabetic nephropathy in rats

Abstract

Aim: The present study was designed to investigate the effect of methanolic extract of Costus pictus (MECP) per se and in combination with drugs (Metformin and Enalapril) used in clinical practice in streptozotocin (STZ) induced diabetic nephropathy (DN) in rats.

Methods: Diabetes was induced in male Wistar rats by a single injection of STZ (50 mg/kg i.p.). After 28 days diabetic rats were divided into six groups. Two groups were treated with MECP (200 mg/kg p.o.), MECP (400 mg/kg p.o.) respectively; one group was treated with metformin (225 mg/kg), enalapril (3.2 mg/kg) combination; and two groups were treated with a combination of metformin, enalapril and MECP (200 mg/kg) and combination of metformin, enalapril and MECP (400 mg/kg) respectively. One group was kept as diabetic control. At the end of the study, body weight, kidney weight, and kidney hypertrophy index were evaluated. Biochemical and antioxidant parameters were evaluated. TGF-β levels in serum were estimated. Histopathology of the kidney was also studied.

Results: The combination therapy showed a significant increase in the body weight, lowered blood glucose levels and ameliorated kidney hypertrophy index in STZ induced diabetic nephropathy in rats. It also normalized the altered levels of serum and urine parameters. Histopathological evaluation revealed that combination therapy reduced the vacuolar degeneration of tubules.

Conclusions: The results indicate that combination therapy of metformin, enalapril, and MECP has beneficial effects in management of diabetic nephropathy.

Keywords: Costus pictus; Diabetic Nephropathy; Enalapril; Metformin; Streptozotocin.

Fig. 1

Effect on urine biochemical parameters in STZ induced diabetic nephropathy in rats. The data are presented as Mean ± S.E.M. (n = 6). ^###p < 0.001 as compared to vehicle control group; ^a(p < 0.001), ^b(p < 0.01) as compared to diabetic control group; ^d(p < 0.001), and ^f (p < 0.05) as compared to standard treatment (M + E) group. Data analysed by a one-way analysis of variance (ANOVA) followed by Turkey’s Kramer multiple test for comparison

Fig. 2

Effect on serum biochemical parameters in STZ induced diabetic nephropathy in rats. The data are presented as Mean ± S.E.M. (n = 6). ^###p < 0.001 as compared to vehicle control group; ^a(p < 0.001), ^b(p < 0.01) as compared to diabetic control group; ^d(p < 0.001), e(p < 0.01) as compared to standard treatment (M + E) group. Data analysed by a one-way analysis of variance (ANOVA) followed by Turkey’s Kramer multiple test for comparison.

Fig. 3

Effect on TGF-β in STZ induced diabetic nephropathy in rats. The data are presented as Mean ± S.E.M. (n = 6). ^###p < 0.001 as compared to vehicle control group; ^a(p < 0.001), ^b(p < 0.01) as compared to diabetic control group; ^d(p < 0.001) as compared to standard treatment (M + E) group. Data analysed by a one-way analysis of variance (ANOVA) followed by Turkey’s Kramer multiple test for comparison.

Fig. 4

Effect on histopathology of kidney tissue (H& E staining). Figure A: kidney tissue of vehicle control rat. Figure B: kidney of tissue of diabetic control rat. Figure C:kidney tissue of rat treated with standard metformin (225 mg/kg) and Enalapril (3.2 mg/kg) (M+E). Figure D: kidney tissue of rat treated with MECP (200 mg/kg)(MECP 200). Figure E: kidney tissue of rat treated with MECP (400 mg /kg) (MECP 400). Figure F: kidney tissue of rat treated with metformin (225 mg/kg), Enalalpril (3.2 mg/kg) and MECP (200 mg/kg) (M + E + MECP 200). Figure G: kidney tissue of rat treated with metformin (225 mg/kg), Enalalpril (3.2 mg/kg) and MECP (400 mg/kg) (M + E + MECP 400). Lesion Grading: Minimal (1), mild (2), moderate (3), and marked (4) Distribution of Lesions: Focal (a), Multifocal (b), Diffuse (c) No abnormalities detected: NAD

Fig. 5

Effect on histopathology of kidney tissue (Masson’s trichome staining). Figure A: kidney tissue of vehicle control rat. Figure B: kidney tissue of diabetic control rat. Figure C: kidney tissue of rat treated with standard metformin (225 mg/kg) and enalalpril (3.2 mg/kg) (M + E). Figure D: kidney tissue of rat treated with MECP (200 mg/kg) (MECP 200). Figure E: kidney tissue of rat treated with MECP (400 mg /kg) (MECP 400). Figure F: kidney tissue of rat treated with metformin (225 mg/kg), enalalpril (3.2 mg/kg) and MECP (200 mg/kg) (M + E + MECP 200). Figure G: kidney tissue of rat treated with metformin (225 mg/kg), enalalpril (3.2 mg/kg) and MECP (400 mg/kg) (M + E + MECP 400). Lesion Grading: Minimal (1), mild (2), moderate (3), and marked (4). Distribution of Lesions: Focal (a), Multifocal (b), Diffuse (c), No abnormalities detected: NAD

Fig. 6

Effect on histopathology of kidney tissue (periodic acid schiff staining). Figure A: kidney tissue of normal control rat. Figure B: kidney tissue of diabetic control rat. Figure C: kidney tissue of rat treated with standard metformin (225 mg/kg) and enalapril. (3.2 mg/kg) (M + E). Figure D: kidney tissue of rat treated with MECP (200 mg/kg) (MECP 200). Figure E: kidney tissue of rat treated with MECP (400 mg /kg) (MECP 400). Figure F: kidney tissue of rat treated with metformin (225 mg/kg), enalapril (3.2 mg/kg). and MECP (200 mg/kg) (M + E + MECP 200). Figure G: kidney tissue of rat treated with metformin (225 mg/kg), enalapril (3.2 mg/kg) and MECP (400 mg/kg) (M + E + MECP 400). Lesion Grading: Minimal (1), mild (2), moderate (3) and marked (4). Distribution of Lesions: Focal (a), Multifocal (b), Diffuse (c) No abnormalities detected: NAD