Figure 7.

MB-PDT mediated the induction of apoptosis by the mitochondria-dependent pathway. MB seemed to selectively bind to mitochondria, where it produced ROS after excitation in combination with light. Then, ROS acted on mitochondria to induce an imbalance between ROS production and antioxidant capacity. Consequently, MB-PDT-mediated oxidative stress caused impairment of mitochondrial integrity and function, resulting in cytochrome c release and loss of mitochondrial membrane potential, which ultimately led to apoptotic cell death.