Abstract: Objective To investigate the effects of purendan superfine powder on retinal vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) expression in diabetic rats. Methods Forty-eight male rats were randomly divided into 4 groups (n=12)：normal control group，diabetes model group，PRD treatment group and doxium treatment group. The diabetes model rats were made by continuous intraperitoneal injection of streptozotocin. After the diabetes animal model was successfully established，the rats in PRD treatment group and doxium treatment group were respectively lavaged with PRD and doxium for 3 months. Immunohistochemical staining，Western blotting was used to assess the expression of VEGF and PEDF protein in retina；RT-PCR was employed to examine the expression of VEGF and PEDF mRNA in retina. 〖WTHZ〗Results〖WTBZ〗 The expression of VEGF protein and mRNA in retina of rats in normal control group were 0.4705±0.0668 and 0.4377±0.0372 respectively，those of rats in diabetic model group were 1.5874±0.1467 and 0.9332±0.0463 respectively, there had significant differences between normal control group and diabetic model group (P<0.01). The expression of VEGF protein and mRNA in retina of rats in PRD treatment group were 0.9050±0.0983 and 0.5251±0.0114 respectively, those of rats in doxium treatment group were 0.9123±0.0548 and 0.5499±0.0320 respectively, there had significant differences compared with diabetic model group (P<0.01); However, there had no significant difference between PRD treatment group and doxium treatment group(EM>P/EM>>0.05). The expression of PEDF protein and mRNA in retina of rats in normal control group were 1.3349±0.1201 and 1.0258±0.0385 respectively，those of rats in diabetic model group were 0.5406±0.0601 and 0.2671±0.0199 respectively, there had significant differences between normal control group and diabetic model group (P<0.01). The expression of PEDF protein and mRNA in reti

Key words: Purendan superfine powder, Diabetes, Retinopathy, Vascular endothelial growth factor, Pigment epithelium-derived factor, Western blotting, RT-PCR, Rat 