Retinal neovascularization is a common cause of vision loss in proliferative diabetic retinopathy, retinopathy of prematurity and age-related macular degeneration. Samul-tang (SMT) is a widely used traditional herbal medicine in East Asia and is also known as Shimotsu-to in Japanese and Si-Wu decoction in Chinese.
This study was designed to evaluate the inhibitory effect of SMT on retinal pathogenic angiogenesis in a mouse model of oxygen-induced retinopathy (OIR).MethodThe mice were exposed to a 75 % concentration of oxygen for five days, starting on postnatal day 7 (P7-P12). The mice were then exposed to room air and were intraperitoneally injected with SMT (10Â mg/kg or 50Â mg/kg) once per day for five days (P12-P16).
On P17, we measured retinal neovascularization and evaluated both the expression of angiogenesis-related proteins and changes in the gene expression level in the mRNA.
Results: SMT reduced the area of the central retina and reduced retinal neovascularization in OIR mice. The protein array revealed that SMT reduced the level of SDF-1 protein expression.
Quantitative real-time PCR revealed that the HIF-1α, SDF-1, CXCR4 and VEGF mRNA levels in the retinas of OIR mice were elevated compared with those of normal control mice. However, SMT decreased the levels of HIF-1α, SDF-1, CXCR4 and VEGF mRNA in OIR mice.
Conclusion: We are the first to elucidate that SMT inhibits the retinal pathogenic angiogenesis induced by ischemic retinopathy in OIR mice.
SMT significantly inhibited retinal neovascularization by downregulating HIF-1α, SDF-1, CXCR4 and VEGF. Based on the results of our study, SMT could be a useful herbal medicine for treating ischemic retinopathy.
Author: Yun LeeChan-Sik KimKyuhyung JoEun SohnJin KimJunghyun Kim
Credits/Source: BMC Complementary and Alternative Medicine 2015, 15:271
Source: 7th Space Interactive
