Figure 2. The effect of exogenous nucleobases and intermediates of pyrimidine biosynthetic pathway on the anti-CVB3 activity of gemcitabine.

Four nucleobases (adenine, guanine, cytosine and uracil) and intermediates (dihydroorotate, orotic acid and UMP) (100 μM) of pyrimidine biosynthetic pathway were treated as described in Figure 1A (A) and in Figure 1B (B). Cytidine was used as a positive control. The average and standard deviation were obtained from three independent experiments. ^*** indicates P < 0.001. (C) Pyrimidine biosynthetic pathway. Tested metabolites were indicated as boxes and metabolites with the significant effect were shown as orange boxes. The salvage pathway affected by gemcitabine was depicted by blue arrows.