Sequoyitol Alleviates High Glucose-Induced Inflammation, Oxidative Stress and Apoptosis of Retina Epithelial Cells

Diabetic retinopathy (DR) is a serious microvascular complication of diabetes, contributing to visual impairment and blindness. Sequoyitol (Seq), a form of inositol derivatives, has been demonstrated to be a therapeutic potential for diabetes and diabetic nephropathy. The aim of this study is to explore the effects of Seq on DR. ARPE-19 cells were cultured in high glucose (HG) condition to simulate DR in vitro. Seq (1, 10 and 20 mu M) was applied for treatment. CCK-8 assay was performed to detect cell viability. Flow cytometry analysis was conducted to determine cell apoptosis rate. The production level of inflammatory cytokines and oxidative stress-related factors were determined using their commercial kits. The protein expressions of corresponding genes were detected using western blotting. The results revealed that Seq significantly increased cell viability and protein expression of PCNA and Ki67 which were decreased after HG induction. HG promoted cell apoptosis by decreasing protein expression of Bcl-2 and increasing protein expression of Bax and cleaved caspase-3, which was then reversed by Seq treatment. Besides, Seq abolished the promoting effects of HG on the production of pro-inflammatory cytokines and oxidative stress-related factors. Furthermore, Seq suppressed the promoting effect of HG on the activation of NF-kappa B signaling by inhibiting phosphorylation of I kappa B alpha and NF-kappa B nucleus translocation. These results indicated that Seq might protect ARPE-19 cells against HG-induced cell viability, apoptosis, inflammation and oxidative stress by regulating NF-kappa B signaling, providing evidence for the potential application of Seq in the therapy of DR.