Spermdine reduced the viability of HeLa cells. Cells treated with spermidine (0, 0.1, 0.5, 1.0 mM) for 8 h. Cell viability was measured using the MTT assay. Results are expressed as the percentage of control and represent the mean ± S.E.M. of three independent experiments performed with triplicate cultures. *p < 0.05, compared with control (A). Images of cells were taken after exposure to spermidine as described above (B).