Effects of Puerarin on Experimental Model of Retinal Vein Occlusion in Rats

Objective To establish a model of retinal vein occlusion(RVO)in rats and to study the effect of puerarin on ischemic retinal disease and the corresponding mechanism.Methods RVO was induced in 10 adult male Sprague-Dawley(SD)rats by laser photothrombosis.Retinal blood flow was examined before and after 1 h of the operation,and model rats with the retinal vein blood flow decreasing by 50%compared to the basic value were chosen and then puerarins(20,40,and 80 mg/kg)were given.The levels of vascular endothelial growth factor(VEGF),interleukin-1β(IL-1β),and nitric oxide(NO)were analyzed.In addition,the histopathology of RVO-eyes was performed.Results RVO-eyes displayed the signs of retinal damage and ischemia on Doppler Flowmeter and histopathology.Puerarin(20,40,and 80 mg/kg)increased blood flow by 9.3%(P<0.05),33.1%(P<0.001),and 41.5%(P<0.001),respectively.On the other hand,the histological changes were less severe at different degrees,relieving the symptoms such as edematous and thick neuroretinal layers,lax,edematous,and disorganized optic fibers layers,swollen and confused inner and outer nuclear layer.Besides,dose-dependent decrease of VEGF and IL-1βand increase of NO in vitreous fluid were observed,with respect to the model group.Conclusion A rat model of laser photochemical-induced RVO is established and a decrease in the retinal blood flow and histological damage is detected.The puerarin has therapeutic benefit in the rat model of RVO,through the pathway of neovascularization,anti-inflammation,and increase of NO.