Astragalus root extract inhibits retinal cell apoptosis and repairs damaged retinal neovascularization in retinopathy of prematurity

Abstract

ABSTRACT Since the functions of Astragalus root extract in retinopathy remain to be unraveled, this study is performed to elucidate whether Astragalus root extract functions in retinal cell apoptosis and angiogenesis in retinopathy of prematurity (ROP). Newborn mice were selected for establishing mice models of oxygen-induced retinopathy (OIR), which were treated with high-, medium- or low-Astragalus root extract. Evans Blue (EB) was perfused to detect the blood retinal barrier. Additionally, the vascular morphology, number of endothelial cell nuclei of neovascularization, proliferation of blood vessels, ultrastructural changes were determined via a series of assays. Moreover, levels of reactive oxygen species (ROS), expression of other factors such as VEGF, PEDF, IGF-1, HIF-1α, Bax, Bcl-2, eNOS, nNOS, and iNOS were detected. Astragalus root extract was found to protect blood-retinal barrier in the OIR model mice through repairing the structure and morphology of retina, inhibiting ROS production, retinal cell apoptosis, as well as improving retinal vascular angiogenesis. Astragalus root extract was also found to decrease VEGF and HIF-1α expression, but enhance PEDF and IGF-1 expression in the OIR model mice, thereby protecting retinas in ROP. This study highlights that Astragalus root extract is able to suppress retinal cell apoptosis and repair damaged retinal neovascularization in ROP, which provides basis for ROP therapy.