Fig. 2

a Emodin enhanced the cisplatin-induced cytotoxicity to T24 and J82 human bladder cancer cells, but had little cytotoxicity on HCV-29 normal bladder epithelial cells. The cell viability of T24 cells could be reversed after pre-treatment by NAC for 2 h. b Emodin enhanced the cisplatin-induced apoptosis of T24 and J82 human bladder cancer cells, and this effect could be reversed by NAC. c Emodin effectively enhanced cellular ROS levels in T24 and J82 human bladder cancer cells, but only slightly elevated ROS levels in HCV-29 normal bladder epithelial cells. d Emodin effectively depleted GSH in T24 and J82 cells. The emodin concentration is 20 μM for T24 cells, and 15 μM for J82 and HCV-29 cell. The cisplatin concentration is 1.5 μg/ml for T24 cells, and 1 μg/ml for J82 and HCV-29 cell. Columns, mean of three experiments; bars, S.D. *p < 0.05, experimental group compared with the control group; S.D. #p < 0.05, NAC treatment group compared with emodin/cisplatin co-treatment group. Each experiment was repeated three times