The attenuation of chlorogenic acid on oxidative stress for renal injury in streptozotocin-induced diabetic nephropathy rats

The present study was undertaken to investigate whether chlorogenic acid (CGA) could protect kidney function against oxidative stress in the diabetic nephropathy (DN) rats. The treatment with CGA could decrease significantly the levels of blood glucose, blood urea nitrogen and serum creatinine in DN rats. Moreover, CGA significantly increased the activity of superoxide dismutase, glutathione peroxidase, and catalase. Moreover, the level of lipid peroxidation malondialdehyde was reduced markedly after CGA administration. Immunohistochemical analysis also showed that CGA downregulated significantly cyclooxygenase-2 protein expression in renal tissue, which is considered as one of the major pathogeneses of oxidative stress. Furthermore, we demonstrated that CGA could block the expression of activating transcription factor-6, C/EBP homology protein and the phosphorylation of eukaryotic initiation factor 2α and double stranded RNA-activated protein kinase-like endoplasmic reticulum kinase. In addition, we attempted to detect the presence of diabetic renal tissues apoptosis-related proteins. Our data provided evidence to support this fact that CGA attenuated oxidative stress in streptozocin-induced DN rats. Its molecular mechanism may inhibit the endoplasmic reticulum-stress response in DN.