Effects of COP and BER on the growth of A549 cells. A. Morphological changes of A549 cells treated with 6.4 μg/mL COP or 4.0 μg/mL BER for 72 h under inverted phase contrast microscope (200 ×). B. Treatment with COP and BER for 72 h inhibited A549 cell growth (P < 0.01) [Pearson Correlation Test, P = 0.0032 for COP; P = 0.0178 for BER] in a dose-dependent manner. Values are means ± SD of 4 independent assays.