TIP increases cellular CoQ levels and decreases FC levels in 4-NB-treated PC12 cells. (A) CoQ levels in PC12 cells corrected for protein in the presence of 4-NB (1 mM, 3 mM, and 5 mM) for 2 days. (B) CoQ levels corrected for protein in PC12 cells in the presence and absence of 1 mM 4-NB for 6 months. (C) FC levels corrected for protein in PC12 cells in the presence and absence of 1 mM 4-NB for 6 months. The data were analyzed using a one-way ANOVA and are expressed as means ± SD (n = 3). *p<0.05, **p<0.01, and ***p<0.001 compared with NGF (−), TIP (−), and 4-NB (−) group.