Fig. 6

curcumin induced ROS and cell death in AsT by downregulating Nrf2. A AsT cells were treated with 6.25, 12.5, 25 μM curcumin for 24 h before cell lysates were collected. Nrf2, HO-1, SOD2, PARP, cleaved PARP, Bcl-2, Bcl-xl and β-actin expression were examined by immunoblotting. B AsT cells were transfected with FLAG-Nrf2. 24 h after transfection cells were then treated with 25 μM curcumin for 24 h before cell lysates were collected. Anti-FLAG immunoprecipitates were analyzed by immunoblot with anti-Nrf2 antibody for detection of the transfection expression levels of Nrf2, whole protein lysates were collected and Nrf2, HO-1, SOD2, PARP, cleaved PARP, Bcl-2, Bcl-xl and β-actin expression were examined by immunoblotting. AsT cells were transfected with FLAG-Nrf2. 24 h after transfection cells were then treated with 25 μM curcumin for 24 h before cells were collected. C Cell viabilities were detected by staining with MTT assay, D apoptosis rates were stained PI/Annex V and analyzed with flow cytometry. E ROS levels were detected with DCF and analyzed with flow cytometry. The data are expressed as the mean ± SD of three independent experiments (n = 9). *p < 0.05, **p < 0.01 versus AsT control group