AIM: To investigate the therapeutic effects and mechanisms of Wu Ling San on retinopathy in diabetic rats.

METHODS: The rats with hyperglycemia were divided into five groups: model group, Wu Ling San high dose group, low dose group, positive control group and normal groups each group of ten. After oral administration for 12wk, the expression of ICAM-1 and CRP in the serum of rats were measured by ELISA. After HE staining, retinal structure was observed under the light microscope. Blood retinal vascular barrier permeability was measured by Evans blue. The vascular endothelial growth factor(VEGF)expression of retinal tissue were observed by immunohistochemistry

RESULTS: Compared with the normal group, the expression of CRP, ICAM-1 and the EB content in diabetic group were increased. The contents of CRP and ICAM-1 and EB permeability in Wu Ling San high dose group were lower than low dose group and positive control group(all P<0.05). There are retinal ganglion cell layer disorder, retinal edema, and positive VEGF immunohistochemistry expression in the diabetic group. Wu Ling San high dose group can improve retinal structure and reduce retinal edema.

CONCLUSION: Wu Ling San can effectively reduce the expression of inflammatory cytokine, VEGF and retina edema in diabetic retinopathy rats, and also can improve the retinal microvascular in order to protect diabetic retinopathy.