Figure 8: The scheme for the involvement of the mitochondrial apoptosis pathway in BA6-induced cytotoxicity in A549 cells. BA6 causes ROS accumulation, depolarization of mitochondrial membrane potential, exhaustion of ATP, inhibition of OXPHOS, and increase of cytochrome C release to cytoplasm, which results in caspase activation towards the intrinsic (mitochondria-mediated) apoptosis pathway.