L-carnitine protects C2C12 cells against mitochondrial superoxide overproduction and cell death

Figure 4 Menadione induces autophagy in C2C12 cells. A: Western blot for the determination of LC3 I and II forms. Initial cells were either treated with L-carnitine, menadione or 3-MA; B: LC3-I and II isoforms were detected by western blotting and quantified. The ratio between I and II forms was calculated and plotted in this figure. The black squares represent L-carnitine treated cells whereas empty circles represent C2C12 cells that were not pretreated with L-carnitine. Empty squares represent cells treated with 5 mmol/L of 3-MA. Each point is the mean of 4 independent experiments (± standard values). For each concentration of menadione, a star indicates a significant difference between untreated and L-carnitine treated cells (P < 0.05).