Fig. 5.

Nicotinamide mononucleotide decreased intracellular ROS, LDH and caspase‐3 level but increased CAT and SOD activities treated with H₂O₂. bEnd.3 cells were pretreated with 300 µm NMN for 24 h and then exposed to 800 µm H₂O₂. (A) ROS was measured by the fluorescent probe DCFH‐DA and imaged by fluorescence microscopy (×20; scale bar = 200 μm). (B) The average fluorescence intensity was calculated by ImageJ software and reflects the intracellular ROS level. C‐F. The activities of cellular CAT, SOD, LDH and caspase‐3. The CAT, SOD and LDH levels were normalized per milligram of protein. The level of caspase‐3 was expressed as the percentage increase in activity compared with the normal group. Results are expressed as means ± SD and are representative of three independent experiments. Data were analysed by one‐way ANOVA with LSD’s test for multiple comparisons. *P < 0.05, #P < 0.05 vs. the control group. #P < 0.05 vs. the H₂O₂ group.