Protective effect of Vitamin D against type II diabetic nephropathy in rats: a possible role of adropin

Background: Diabetic nephropathy (DN) is a common complication among type II diabetic patients which may lead to end stage renal disease. Oxidative stress has been found to play a part in the pathophysiology of DN. Several studies have demonstrated the effective nephroprotective role of vitamin D to counteract the progression of DN, although the exact mechanisms are not yet fully understood. Adropin release has been recently linked to be one of the vitamin D effects and was reported to exert its antioxidant effects via nuclear factor erythroid 2-related factor 2 (Nrf2). Aim: To examine the nephroprotective effects of Vitamin D focusing on adropin-Nrf2 axis as one of the possible underlying mechanisms of vitamin D in rats. Materials and Methods: Thirty two albino male adult rats were used in this experiment. Rats were randomly and equally divided into four groups:(GI) was the control, (GII) received vitamin D, (GIII) was the diabetic model, and (GIV) was the diabetes+ vitamin D group. Results: Rats that received vitamin D (0.03 µg/kg/day) for 8 weeks revealed significant lower insulin resistance and oxidative stress state, a significant improvement of kidney dysfunction that was confirmed with histopathological examinations for kidney, and significantly higher levels of serum adropin in association with a significant higher renal mRNA expression of Nrf2. Conclusion: Vitamin D administration has a renoprotective effect in DN in type II diabetic rats. The antioxidant effects of vitamin D may be in part related to the adropin- Nrf2 axis.