The superiority of rosmarinic acid over vitamin e in preventing development and inhibiting progression of diabetic nephropathy in rats

Abstract

Background: Oxidative stress plays an important role in podocyte injury and hence in the development and progression of diabetic nephropathy (DN). The present study was to compare the effect of antioxidant rosmarinic acid (RA) and vitamin E (VtE) in preventing development and inhibiting progression of DN in rats. Methods: Sixteen male Wistar rats were divided into 4 groups each of 4. The 1st group acts as normal rats. The 2nd group acts as untreated-diabetic rats. The 3rd group acts as treated diabetic rats with RA at doses 75 mg/kg/day, and the 4th group acts as treated diabetic rats with VtE at dose 400 mg/kg/day and treatment continued for 8 weeks. Urinary level of podocin, nephrin, albumin, and serum cystatin C levels were measured at the end of the study by ELISA. Immunohistochemistry were used to examined the expression of p65 NF-kB whereas the expression of podocin and nephrin glomerulus were examined by immunofluorescence. Results: The excretion of nephrin, podocin and albumin urine, expression of p65 NF-kB, and level of cystatin C serum were significantly lower in the RA group compared with the VtE group, whereas expression of glomerular nephrin and podocin in the RA group were higher compared with the VtE group. Compared to the untreated-diabetic rats, the expression of glomerular nephrin and podocin, and cystatin C serum level in the VtE group did not differed significantly. Conclusions: In streptozotocin-induced diabetic rats, RA superior than VtE in preventing development and inhibiting progression of diabetic nephropathy.