Background:Dihydroartemisinin (DHA) is a semisynthetic derivative of artemisinin and has antiproliferative effect. However, such effects of DHA have not yet been revealed for bladder cancer cells.Methods:We used as bladder cancer cell lines to examine the effect of DHA on the cell viability, cell apoptosis, and monitoring of mitochondrial membrane potential (ΔΨm) changes. Furthermore, the effect of DHA on the reactive oxygen species (ROS) production and cytochrome c release were also detected. We employed MTT assay to investigate the cell proliferation effect of DHA on the EJ-138 and HTB-9 human bladder cancer cells. Annexin/PI staining, caspase-3 activity assay, Bcl-2/Bax protein expression, mitochondrial membrane potential assay, cytochrome c release, and ROS analysis were used for apoptosis detection.Results:DHA significantly reduced cell viability in a dose-dependent manner. Cytotoxicity of DHA was suppressed by N-acetylcysteine. The growth inhibition effect of DHA was related to the induction of cell apoptosis, which were manifested by annexin V-FITC staining, activation of caspase-3. DHA also increased ROS generation, cytochrome c release, and loss of mitochondrial transmembrane potential (ΔΨm) in cells. In addition, the downregulation of regulatory protein Bcl-2 and upregulation of Bax protein by DHA were also observed.Conclusions:These findings demonstrated that DHA induces apoptosis through mitochondrial signaling pathway. These suggest that DHA may be a potential agent for induction of apoptosis in human bladder cancer cells.