Effects of melatonin on cell viability and apoptosis in high glucose-treated HT22 cells after SIR operation. (A–C) Cell viability was measured by the CCK8 kit. (D) Representative images for apoptosis assessed by flow cytometry. (E) Quantitative analysis of the levels of apoptosis. Data were presented as the mean ± SEM (n = 6). ap < 0.05 vs. control group; bp < 0.05 vs. SIR+V group; cp < 0.05 vs. SIR+Mel group; ep < 0.05 vs. Mel (25 μM).