The Effects of Korean Red Ginseng and Irbesartan on Inhibition of Diabetic Nephropathy

Yoo, Eun Gyong; Ganbaatar, Erdenetuya; Kim, Duk Hee; Hong, Soon Won; Lee, Kyung Ryul

Abstract

PURPOSE: Ginseng has been reported to reduce blood glucose levels in diabetic animals and patients, and it is also reported to slow the aging process by acting as an anti-atherosclerotic agent or as an anti-oxidant. This study was designed to investigate whether ginseng and irbesartan can prevent the development of diabetic nephropathy in streptozotocin-induced diabetic rats.
METHODS
Diabetes was induced in 7 week-old male Sprague-Dawley rats by intravenous injection of 60 mg/kg streptozotocin. Ginseng(1 g/kg/day) or irbesartan (20 mg/kg/day) was given to diabetic rats for 25 weeks. Blood glucose and body weight were checked weekly and urinary albumin excretion was evaluated every 6 weeks. At the end of the experiment, the kidneys were weighed and sliced for microscopic examination. Glomerular size and hyaline deposition were measured on light microscopy(on Masson' trichrome stain and PAS stain) and thickness of glomerular basement membrane(GBM) on electron microscopy. Renal histologic findings of ginseng or irbesartan treated rats were compared with those of normal control and diabetic control groups.
RESULTS
The weight gain in diabetic rats was significantly reduced, and the final body weight of diabetic rats was lower than that of normal control rats. There was no significant difference in body weights between the diabetic control, ginseng, and irbesartan treated groups. Mean levels of blood glucose were significantly increased in diabetic rats compared to normal rats, but there was no significant difference in blood glucose among the three groups of diabetic rats. Urinary albumin excretion was increased in the diabetic groups compared to the normal control group, and it was significantly decreased in the irbesartan treated group compared to the diabetic control group at 13th week of treatment. At the end of the experiment, the kindeys of the diabetic rats were examined and showed significantly enlarged than those of the normal rats, and the ratio of kidney weight to body weight was decreased in the ginseng treated group compared to the diabetic control and irbesartan treated group. There was no significant difference in the size of glomerulus, the thickness of GBM, and glomerular hyaline deposition among the three diabetic groups.
CONCLUSION
There was no significant hypoglycemic effect of ginseng in streptozotocin-induced diabetic rats. Renal hypertrophy was relatively milder in the ginseng-treated group, but there was no difference in findings of renal histology between the treatment groups.