Chromatin condensation and nuclear fragmentation typical for apoptosis induction were visualized by fluorescence microscopy of Hoechst 33342-stained and TEM. After treatment with 10 μg/ml of Ardipusilloside I for 24 h (B) and 48 h (C) or without (A) Ardipusilloside I, Mc3 cells were incubated with Hoechst 33342 at a final concentration of 1.5 μM for 10 min. Red arrows show the characteristic morphological changes of apoptosis, including nuclear condensation, boundary aggregation and splitting, and DNA fragmentation. Magnification 400×. (D) Mc3 cells in the control group had a normal structure with a large and round nucleus, uniform chromatin density, and clear nucleolus. Magnification 6000×. (E) Mc3 cells treated with 10.0 μg/ ml of ardipusilloside I for 24 h showed chromatin condensation. Magnification 6000×. (F) Mc3 cells treated with 10.0 μg/ ml of ardipusilloside I for 48 h showed typical cell shrinkage, chromatin condensation, and membrane blebbing. Magnification 6000 ×.