The Effect of Methylene Blue and Its Metabolite—Azure I—on Bioenergetic Parameters of Intact Mouse Brain Mitochondria

Methylene blue helps mitochondria, the energy factories in our cells, move electrons more smoothly so they don’t accidentally create harmful waste molecules called reactive oxygen species.

In a lab test with mouse brain cells, a chemical called methylene blue makes the energy-producing parts of the cells work harder without using energy to make ATP, while another chemical called azure I doesn’t do anything. This suggests methylene blue might be messing with how the cells normally control their energy production.

Scientists found that a blue dye called methylene blue can help fix a broken energy system in mouse brain cells, but a related chemical called azure I can't — meaning only the original dye can jump over a specific energy block.

A chemical called Azure I, which comes from methylene blue, doesn’t fix the energy power plants in mouse brain cells—even though it’s better at blocking certain brain enzymes. This means it might work in other ways, not by helping cells make energy.

In lab tests on mouse brain cells, methylene blue makes more hydrogen peroxide than azure I, but azure I is more efficient—it creates more of this chemical per bit of oxygen it uses. So even though it makes less overall, it’s more wasteful with oxygen.

Two chemicals, methylene blue and azure I, make mouse brain cells produce a lot more hydrogen peroxide — over two and a half times more in some cases — when tested in a lab dish. This suggests they cause the tiny energy factories inside the cells to make more of this potentially harmful substance.