Figure 2.

Function of methylene blue (MB) as an alternative mitochondrial electron transfer carrier and regenerable antioxidant. MB accepts electron from NADH in the presence of complex I. Upon the redox cycle (MB- MBH2-MB), electrons are delivered to cytochrome c in an alternate route despite the inhibition of complex I and III. The distinct redox property enables MB as a regenerable anti-oxidant in mitochondria that distinct from the traditional free radical scavenges.