AIM: To investigate the protective effect of salvianolic acid B on retina and its influence on angiogenesis in retinal vein occlusion(RVO)injured rats.

METHODS: SD rats were randomly divided into control group, model group and salvianolic acid B group, with 10 rats in each group. In addition to the control group, rats in model group and salvianolic acid B group were induced RVO by Bengal red combined with laser photodynamic method. The rats in salvianolic acid B group were intraperitoneally injected with salvianolic acid B 50 mg/(kg·d), while the rats in control group and model group were only given the same amount of normal saline for 21 consecutive days. Fundus fluorescein angiography(FFA)was used to observe the retinal vein structure before and after administration. HE staining was used to observe the pathological changes of rat retina. The retinal function of rats was evaluated by electroretinogram(ERG). The fluorescence expression of vascular endothelial growth factor A(VEGFA)in retina of rats in each group was detected by immunofluorescence staining. The relative expression of HIF-1α, STAT3, p-STAT3 and VEGFA proteins in retinal tissue were detected by Western blotting.

RESULTS: Compared with the control group, the blood flow at the retinal obstruction in the model group was recanalized, and the effective collateral circulation was abundant, but the shape was irregular, and there was fluorescence leakage. In salvianolic acid B group, the retinal vein circulation recovered, the shape became regular gradually, and the collateral vessels decreased. The retina of the model group and salvianolic acid B group showed different degrees of pathological damage. At the same time, the amplitude of ERG a wave and b wave, the thickness of retinal total layer(RTL), inner nuclear layer(INL)and outer nuclear layer(ONL)decreased, the fluorescence intensity of VEGFA enhanced, and the relative expression of HIF-1α, p-STAT3 and VEGFA protein increased(P<0.05). Compared with the model group, the retinal histopathological damage of salvianolic acid B rats was alleviated, the amplitude of ERG a-wave and b-wave, the thickness of RTL, INL and ONL were increased, the fluorescence intensity of VEGFA was weakened, and the relative expression of HIF-1α, p-STAT3 and VEGFA proteins was decreased(P<0.05).

CONCLUSION: Salvianolic acid B can alleviate the retinal histopathological injury and improve retinal function in RVO rats, which may be related to inhibiting the activation of HIF-1α/STAT3/VEGFA pathway and reducing angiogenesis.