Effect of DEPs on intracellular GSH levels in HBMVEC cells. GSH levels were measured after 24 hours of treatment with various concentrations of DEPs (10 µg/ml, 25 µg/ml, and 50 µg/ml). Values represent mean±SD. All experiments were performed in triplicates, and the values reported are mean ± SD. (a: different from control group, b: different from 10 µg/ml [DEP] group, and c: different from 25 µg/ml [DEP] group, p<0.05).