Fig. 4

Fer-1 rescued the anti-tumor effects of oridonin in OS cells. A-C The expressions of ferroptosis markers FTH1 and GPX4 in oridonin-treated 143B and U2OS cells were increased after added Fer-1. Actin as reference. (n = 3, * p < 0.05, ** p < 0.01, *** p < 0.001, ****p < 0.0001, vs. normal). D-G The 143B and U2OS cells were co-treated with oridonin and Fer-1, and the cell viability was examined by CCK-8 assays. (n = 3, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, vs. normal). H-K Compared the intracellular contents of ROS (20X) (H-I) in the oridonin and co-treated OS cells, meanwhile, observed the change of mitochondrial membrane potential (40X) (J-K). Cells treated with ROSUP and CCCP were used as positive control (n = 3, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, vs. normal)