Echinacoside protects retinal ganglion cells from ischemia/reperfusion-induced injury in the rat retina

OBJECTIVE: To investigate whether echinacoside (ECH) protects the retina against ischemia/reperfusion (I/R) injury and the underlying mechanisms. METHODS: Adult male Wistar rats were randomly divided into four groups: sham, sham plus ECH, I/R plus vehicle, and I/R plus ECH. Before the retinal I/R injury produced by high intraocular pressure (HOP), ECH was administered (20 mg/kg daily) for 7 days. The level of retinal cell damage was evaluated using Fluoro-Gold (FG) retrograde labeling and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) analysis 7 days after I/R. Optic nerve histology was analyzed with transmission electron microscopy. Levels of retinal malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were determined. The expression of apoptosis-associated factors (Apaf-1, Parp, and Bad) were analyzed with western blotting and quantitative real-time PCR (qPCR). The production of proinflammatory cytokines (tumor necrosis factor-α [TNFα], interleukin-1 beta [IL-1β], and IL-6) was analyzed with enzyme-linked immunosorbent assay (ELISA) 7 days after the I/R injury as well. RESULTS: The administration of ECH not only preserved retinal morphology but also attenuated retinal inflammation and apoptosis at 7 days after the I/R injury and decreased I/R-induced oxidative stress in the retina statistically significantly. CONCLUSIONS: ECH protected against I/R-induced retinal injury, via activation of antioxidant enzymes and suppression of inflammation. Therefore, ECH could be a potential therapeutic candidate for the treatment and management of I/R retinal diseases.