FIGURE 6.

Effect of cigarette IQOS extracts on apoptosis (A) and on cell cycle (B). Human gingival fibroblasts were treated with undiluted and diluted to 6.25% extracts for 24 h. Cells were collected and stained with PI and analysed by flow cytometry for percentage of apoptotic cells (a) and for percentage of cell in different phases of cell cycle (B). The values represent the mean ± SD of three independent experiments performed in triplicate for each extract. Differences vs. control: *p < .001; **p < .05