The effect of Shengpuhuang-tang on retinal inflammation in streptozotocin-induced diabetic rats by NF-κB pathway

Ethnopharmacological relevance: Diabetic retinopathy (DR) is a terrible microvascular disorder causing blindness. Retinal inflammation is the early stage in DR, which is believed to play a crucial role in the development of it. Shengpuhuang-tang (ST), a traditional herbal formula, which has effective treatment of fundus bleeding disorder. ST exerts protective effects against DR in rats, but its underlying mechanism of this efficacy remains unknown. Thus, the objective of this study is to examine the mechanism and the efficacy of ST on retinal inflammation in streptozotocin-induced diabetic rats. Materials and methods: The administration of ST was initiated at 4 weeks after diabetes induction and continued for 12 weeks. Retinal vessel permeability was evaluated by using FITC-dextran and Evans blue. Retinal leukostasis was evaluated with FITC-coupled concanavalin A lectin (ConA). Moreover, western blotting was performed to detect TNF-alpha, ICAM-1 and the relative expression levels of I kappa B alpha, IKK beta, and p65 in vivo. Results: The results showed that the retinal inflammation in streptozotocin-induced diabetic rats was significantly decreased by ST. ST could decreased the expression levels of TNF-alpha, ICAM-1 and inhibited the expression of p-IKK beta, p-p65 and I kappa B alpha. It could also inhibited the nuclear transfer of p65. Conclusions: In conclusion, these data suggested that ST may have potential treatment strategies against early stage of diabetic retinopathy through NF-kappa B pathway.