Effect of PGL on apoptosis- and cell cycle-associated mRNA levels.

(A) PGL upregulated the expression of apoptosis-associated genes; (B) PGL downregulated the expression of cell cycle-associated genes. A549 cells were treated with 50 μg/mL PGL for 24, 48, and 72 h, then the mRNA levels of apoptosis- and cell cycle-related genes were examined by RT-qPCR (n = 3). Values are expressed as the mean ± SD of three independent measurements. Significant differences between the PGL-treated and control groups are indicated as * (p < 0.05) or ** (p < 0.01).