Association of nicotinamide adenine dinucleotide content and glucose levels with the oxidative stress in human leukaemia cells

Objectives: This research underscores the pivotal role of NAD in regulating the oxidant/antioxidant system and controlling ROS production in cancer cells. The present study sought to determine whether increasing NAD levels through supplementation can effectively reduce ROS generation in different cell types, including cancer cells. Methods: HL-60 cells and Raji cell lines were cultured, and HL-60 cells were differentiated into neutrophil-like cells using all-trans retinoic acid (ATRA). Oxidative stress was quantified using the thiobarbituric acid reactive substance (TBARS) assay and NAD. Cells were then challenged with glucose, and the oxidative stress test was repeated. The HL-60 cells are CD38-negative, and the Raji cells are CD38-positive. Results: NAD levels in HL-60 cells-CD38 negative were significantly (p=0.001) higher than ATRA-differentiated cells and RAJI cells. The TBARS levels were significantly (p<0.05) higher in cells with lower levels of NAD, particularly in ATRA-differentiated cells, compared to RAJI cells and undifferentiated HL-60 cells. Regarding the incubation of cells with glucose or NAD, cells were incubated with 100 µM NAD for 24 hours to elevate intracellular NAD+ levels. Interestingly, ROS production was significantly reduced in ATRA-differentiated cells, undifferentiated HL-60 cells, and Raji cells after NAD treatment. Conclusion: Manipulating NAD concentration may indirectly regulate ROS production, potentially offering adjuvant therapeutic advantages in treating diseases associated with oxidative stress, such as cancer.