Intervention with cilostazol attenuates renal inflammation in streptozotocin-induced diabetic rats

An inflammatory reaction is commonly found in the pathogenesis of diabetic nephropathy (DN). Cilostazol, a type 3 phosphodiesterase (PDE) inhibitor, has been previously reported to be anti-inflammatory, independent of an anti-platelet property. In the present study, we evaluated the hypothesis that cilostazol has protective effects on diabetic nephropathy by modulating the inflammatory process.

Cilostazol was administered (27 or 9 mg kg(-1)d(-1)) to streptozotocin (STZ)-induced diabetic rats for eight weeks. We studied the kidney expression of vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1 by immunofluorescence, western blotting and real-time PCR. The renal monocyte chemoattractant protein (MCP)-1 and vascular endothelial growth factor (VEGF) levels were examined by ELISA. The nuclear factor (NF)-kappaB-DNA binding activity was assessed by electrophoresis mobility shift assay (EMSA).

Our results showed cilostazol inhibited diabetes-induced hypertrophy of the glomeruli and infiltration of inflammatory cells, as well as the increase in the VCAM-1 and ICAM-1 mRNA and protein expression, and MCP-1 and VEGF contents in the kidneys. Consistent with these findings, cilostazol attenuated the enhanced activation of NF-kappaB in diabetic rats.

These results demonstrate that the renoprotective effects of cilostazol may be mediated by its anti-inflammatory actions, including inhibition of NF-kappaB activation and the subsequent decrease in proinflammatory factors, such as VCAM-1, ICAM-1, MCP-1 and VEGF expression in kidneys of diabetic rats.