Effects of niacinamide on HEK-293 cells apoptosis induced by IL-1β in vitro

OBJECTIVE: To investigate protective effects and mechanisms of niacinamide on HEK-293 cell apoptosis induced by IL-1β in vitro. METHODS: Cultured HEK-293 cells were divided into 6 groups, and various concentrations of IL-1β and niacinamide were added to the mediums for intervention. After 3 d of intervention, cell proliferation activity, Annexin V-PI staining, intracellular caspase-3, 8 and 9 activity, intracellular ATP concentration, intracellular reactive oxygen species level and mitochondrial membrane potential were detected respectively. RESULTS: The MTT absorbance were increased significantly, the apoptotic ratios were descended, the caspase-3, 8 and 9 activities were all decreased, the ATP concentrations were increased higher significantly in groups intervented with niacinamide compared with group 3 but the reactive oxygen species levels in groups intervented with niacinamide were decreased compared with group 3 significantly, while the red/green fluorescence intensity ratios in groups intervented with niacinamide were increased obviously compared with group 3 in mitochondrial membrane potential assay. CONCLUSION: Niacinamide can promote HEK-293 cells proliferation and inhibit HEK-293 cells apoptosis induced by IL-1β in vitro. The protective effects of niacinamide against cell apoptosis mainly acts via protection of the mitochondrial function to improve cellular mitochondrial energy metabolism.