Sodium ferulate attenuates high-glucose-induced oxidative injury in HT22 hippocampal cells

The aim of the present study was to investigate the protective effects of sodium ferulate (SF) on HT22 hippocampal cells under a high glucose concentration. Cells were cultured in normal glucose (25 mM D-glucose) or high glucose (50 mM D-glucose) with various concentrations of SF (50, 100, 250 or 500 µM) for 0, 48 and 72 h. Cell viability was tested using a Cell Counting Kit-8 assay. Reactive oxygen species (ROS) production was detected using flow cytometry. The expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and nuclear factor-κB (NF-κB) at the mRNA and protein levels were detected using a reverse transcription-quantitative polymerase chain reaction analysis and western blotting. HT22 hippocampal cell viability was revealed to be substantially decreased following culturing in high glucose medium (50 mM) for 48 and 72 h. The addition of 100 µM SF abrogated this high-glucose-induced toxicity, but higher concentrations of SF (250 and 500 µM) were harmful to the cells. Furthermore, a high glucose concentration increased the generation of ROS, downregulated the expression of Nrf2/HO-1 and upregulated the expression of NF-κB subsequent to culturing for 72 h, whereas the addition of the appropriate concentration of SF attenuated these effects. To the best of our knowledge, the present study is the first to report such results and provide evidence that SF protects HT22 cells from high glucose-induced toxicity by activating the Nrf2/HO-1 pathway and inhibiting the expression of NF-κB, which may be of therapeutic value in diabetic encephalopathy.