Therapeutic Approaches to Delay the Onset of Alzheimer's Disease
Figure 3
The proposed model for the interaction of methylene blue with specific mitochondrial and cellular components. ETC followed by roman number refers to the specific components of electron transport chain (ETC) of the mitochondria. MIM, MOM, and IMS refers to the mitochondrial inner membrane, mitochondrial outer membrane, and intermembrane space, respectively. MB and MBH2 refer to oxidized and reduced forms of methylene blue, respectively. The four complexes are: complex I (ETC I), complex II (ETC II), complex III (ETC III), and complex IV (ETC IV) in addition to ATP synthase (i.e., complex V). The electron transfer through each one of the ETC starts at ETC I, which catalyzes two electrons oxidation of NADH and continues until water is formed on ETC IV. Coenzyme Q serves as low-molecular weight electron carrier from ETCs I and II to III. Cytochrome c (cyt c) serves as electron carrier from ETC III to ETC IV. Production of superoxide radical from complex I is proposed to be prevented by MB, which serves as electron carrier that competes with molecular oxygen on the electrons “leaking” from complex I. During this process MB is converted to MBH2. Then MBH2, a reduce MB, carries the electrons to cytochrome , which is then oxidized by ETC IV [55].
