DNA content frequency histograms representing HeLa cells after 24 h from (a) untreated cultures (b) cultures treated with MBS extract concentration <IC50 (c) cultures treated with MBS extract IC50 (d) cultures treated with MBS extract concentration >IC50. The treatment affected the cell cycle distribution and induce apoptosis. The cells were stained with PI. Fluorescence of the PI-stained cells was measured using CyAn ADP appartus and Summit (V4.3) software. The software program provides the estimate of percentage of cells with fractional DNA content (apoptotic cells: R2) and cells in G0/G1 (R3), S (R4), and G2/M (R5) phases of the cycle. Total cell number (R1).