Fig. 1

β-Carotene induces apoptosis in AGS cells. The cells were cultured with β-carotene (final concentration of 100 μM) for 12 h (a, b) or for various periods (0, 4, 8, 12 h) (c). a Cell viability was determined by counting the number of viable cells. The viability of cells treated without β-carotene (none) was set at 100 %. The results are expressed as the mean ± SEM of four separate experiments. *p < 0.05 versus cells treated without β-carotene (none). b DNA fragmentation was detected by measuring the amount of oligonucleosome-bound DNA in the cell lysate. The relative increase in nucleosomes in the cell lysate, determined at 405 nm, was expressed as an enrichment factor. DNA fragmentation in cells treated without β-carotene (none) was set at 1. The results are expressed as the mean ± SEM of four separate experiments. *p < 0.05 versus cells treated without β-carotene (none). c Apoptotic indices (protein levels of cytochrome c, Bcl-2, and Bax) were assessed with Western blot analysis. Actin served as a loading control