MAOB and Parkinson disease: With a high lipid solubility and a great accessibility into the brain, MPTP can be catalyzed by monoamine oxidase B located in the outer membrane of glial cells to produce the DA structural analogue, while MPP+ can trigger PD-like symptoms by inducing typical apoptosis in midbrain dopamine neurons and model cell lines (such as SH-SY5Y and PC12 cells), accompanied by reactive oxygen species (ROS) production, caspases activation, and DNA fragmentation.