Figure 7.
Ridaifen (RID)‐B‐induced apoptosis is not related to reactive oxygen species (ROS). (a) Jurkat cells were incubated with or without 10 mM 3,3,5,5‐tetramethyl‐1‐pyrolline‐N‐oxide (TMPO) for 2 h, and subsequently incubated with or without 4 µM RID‐B or IC50 value of tamoxifen (TAM) (control) for 4 h. Ten minutes prior to the end of incubation, 5 µg/mL DHR123 was added. Rhodamine fluorescence was measured by spectrofluorometer, and the results are presented as a comparison to the non‐additive control. Data are representative of three independent experiments. (b) Jurkat cells were incubated with or without 10 mM TMPO for 2 h, and thereafter incubated with or without 4 µM RID‐B for 4 h. Cell viability was estimated by WST‐8 assay. Each bar denotes the standard deviation (n = 3). (c) Jurkat cells were incubated with or without 10 mM TMPO for 2 h, and thereafter incubated with or without 4 µM RID‐B for 4 h. The cells were lysed, and DNA was prepared. DNA fragmentation was analyzed by agarose gel electrophoresis. (d) Jurkat cells were incubated with or without 10 mM TMPO for 2 h, and thereafter incubated with or without 4 µM RID‐B for 4 h. The caspase‐3 assay was then carried out. The results are presented as a comparison with the non‐additive control for each of the cells. Data are representative of three independent experiments. (e) Jurkat (bcl‐2) cells were incubated with or without 4 µM RID‐B for 4 h. Ten minutes prior to the end of incubation, 5 µg/mL DHR123 was added. Rhodamine fluorescence was measured by spectrofluorometer, and the results are presented as a comparison with the non‐additive control. Data are representative of three independent experiments. (f) Jurkat cells were incubated with or without 30 µM Ac‐DEVD‐CHO for 1 h, and thereafter incubated with or without 4 µM RID‐B for 4 h. Ten minutes prior to the end of incubation, 5 µg/mL DHR123 was added. Rhodamine fluorescence was measured by spectrofluorometer, and the results are presented as a comparison to the non‐additive control. Data are representative of three independent experiments.