Fig. 2.

MAN elicited ROS accumulation in A549 cells by downregulation of NAMPT/NAD. (A) Effect of MAN on intracellular NAD levels. (B) The time-dependent inhibition of MAN on NAMPT expression (top) and the concentration-dependent inhibition of MAN on NAMPT expression (below). (C) NMN supplementation (200 μM for 24 h) upregulated NAMPT/NAD in A549 cells. (D) NAC and NMN co-treatment eased MAN-induced ROS accumulation. (E) The antagonistic effect of NAC and NMN against MAN-induced inhibition on proliferation of A549 cells. Data are expressed as means ± SD (n = 3). Statistical analyses were performed using the SPSS and differences among different groups were evaluated using ANOVA followed by Tukey post hoc test. *P < 0.05 compared with normal control (Fig. 2A and C), **P < 0.01 compared with normal control (Fig. 2A), **P < 0.01 compared with MAN-treated cells (Fig. 2E)