Experimental Study Of Anemoside B4 In The Treatment Of Early Diabetic Retinopathy In Rats

Objective:To investigate the influence of Anemoside B4 on the expressions of NF-?B and NF-?B-mediated inflammatory factors as well as on the apoptosis-related genes in the retina of diabetic rats.To investigate the effects Anemoside B4 in treating early-stage diabetic retinopathy and its possible mechanism,and explore a potential new intervetion for the occurrence and development of early diabetic retinopathy.Methods:Sixty Sprague-Dawley rats were randomized into three groups,i.e.,normal control(CON),diabetic rats(DM)and diabetic rats treated with Anemoside B4(B4).The rats were rendered diabetic with intraperitoneal injection of streptozotocin(STZ,60 mg/kg).For the rats in B4 group,Anemoside B4(5 mg/kg)were injected intraperitoneally,twice/day.The rats in CON and DM groups were injectied with equivalent volume of normal saline.Eight weeks later,the rats were killed and the retinas were harvested for examination.The retinal paraffin section were stained with Sudan red for morphological evaluation.The mRNA expressions of NF-?B,IL-1?,IL-6,TNF-? and Caspase-3 were detected with real-time PCR,and the protein levels of NF-?B,Bax and Bcl-2 were detected with Western blot.Immunohistochemical method was used to locate and quantify Bax and Bcl-2.Results:In comparison with the CON group,the body-weights of the rats in DM and B4 group were significantly reduced,and blood glucose levels were increased during the same period,and the difference was statistically significant;while the blood glucose and body-weights of the rats in DM and B4 group were not significantly different.In the DM rats,the retinal outer nuclear layer(ONL)was thinner and cell arrangement was disordered when compated with those of CON rats.The morphology of the retina of diabetic rats was improved after the treatment with Anemoside B4.As compared with the CON group,the mRNA expression of NF-?B,IL-1?,IL-6,TNF-? and Caspase-3 in the retina of the DM group were significantly increased,while the treatment with Anemoside B4 could decrease their expressions.Similarly,Western blot examination demonstrated increased expressions of NF-?B and Bax and decreased Bcl-2 expression in the retinal of the DM rats as compared with the CON rats.After treatment with Anemoside B4,the expressions of NF-?B and Bax were decreased,while the expression level of Bcl-2 was significantly increased.Immunohistochemistrical examiantion showed that the Bax expression of significantly increased while the Bcl-2 expression was decreased in the retina of the DM rats when compared with those in the CON rat.Following the treatment with Anemoside B4,i.e.,in B4 group,the expression level of Bax decreased significantly and Bcl-2 increased as compared with the DM group.Conclusions:(1)Anemoside B4 could improve retinal morphology of the diabetic rats,showing a protective effect.(2)The protective effects and mechanism of Anemoside B4 on the retina in diabetic rats may be related to its inhibiton of NF-?B and NF-?B-mediated inflammatory factors,and to its anti-apoptotic effect.(3)Anemoside B4 might be a potential drug for the treatment of diabetic retinopathy and merits further investigation.