Eriodictyol inhibits high glucose-induced oxidative stress and inflammation in retinal ganglial cells

Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes mellitus and is considered as a leading cause of blindness. Oxidative stress and inflammation are significant drivers for the development of DR. Eriodictyol, a flavonoid compound, was proved to possess anti-inflammatory, antioxidative, and antidiabetic activities. However, the role of eriodictyol in DR has not been unveiled. In the current study, we explored the protective effects of eriodictyol on high glucose (HG)-induced rat retinal ganglial cells (RGCs). The results suggested that eriodictyol improved cell viability of HG-induced rat RGC-5 cells in a dose-dependent manner. Eriodictyol reduced the reactive oxygen species production and increased the activities of superoxide dismutase, glutathione peroxidase and catalase in rat RGC-5 cells in response to HG stimulation. The production of proinflammatory cytokines including tumor necrosis factor alpha and interleukin-8 was diminished after eriodictyol treatment. Eriodictyol also suppressed cell apoptosis induced HG in rat RGC-5 cells. Furthermore, eriodictyol enhanced the nuclear translocation of nuclear factor erythroid-2 (E2)-related factor 2 (Nrf2) and elevated the expression of antioxidant enzyme heme-oxygenase-1 (HO-1). These findings suggested that eriodictyol protects the RGC-5 cells from HG-induced oxidative stress, inflammation, and cell apoptosis through regulating the activation of Nrf2/HO-1 pathway.