*4.5. Cell Cycle Analysis*

A549 cells were seeded into six-well plates (2 × 10<sup>5</sup> cells/well). After 24 h, the cells were treated with concentrations corresponding to IC20 or IC50 values of DOX with 20 μg/mL of extracts or with combination of IC20 or IC50 DOX with 20 μg/mL of extracts. The cells were incubated, collected, and fixed. Afterward, the cells were washed, treated with RNase A, stained with propidium iodide, and analyzed using FACSCalibur flow cytometer (BD Biosciences Franklin Lakes, NJ, USA) and CELLQuest software (BD Biosciences) [44]. The obtained results are presented as mean ± SD of the results obtained in three independent experiments.

#### *4.6. Cellular Uptake and Retention of Doxorubicin*

A549 cells were seeded in six-well plates (2 × 10<sup>5</sup> cells/well). For DOX uptake experiments, the cells were treated with IC50 DOX alone or in combination with 40 μg/mL of extracts. After 24 h, the cells were washed with the medium and analyzed using FACSCalibur. For DOX retention, the cells were treated with IC50 of DOX for 24 h, and afterward, the samples were washed and treated with 40 μg/mL of extracts or with the nutrient medium only. After 24 h, the treated cells were washed again and analyzed. Fluorescence intensity measured in cells treated with DOX alone was used as a mark of 100% DOX retention/uptake. All data are presented as mean ± SD obtained in three independent experiments.
