When the fat tissue was given serotonin (a chemical the body uses in mood and digestion), it made over twice as many harmful molecules — but adding methylene blue cut that increase in half, showing the enzyme MAO-A is involved.
Scientific Claim
Exposure of human cardiovascular adipose tissue to serotonin (10 µM) increases hydrogen peroxide production by more than twofold, an effect partially reversed by co-incubation with 0.1 µM methylene blue, indicating MAO-A activity contributes to substrate-dependent oxidative stress.
Original Statement
“Incubation with SR more than doubled the H2O2 production in both types of adipose tissue, an effect that was partially reversed by MB.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The study directly manipulated substrate (serotonin) and inhibitor (MB) exposure in tissue samples and measured quantitative changes in H2O2. The claim accurately reflects the observed interaction without implying clinical causation.
Evidence from Studies
Supporting (1)
Methylene blue reduces monoamine oxidase expression and oxidative stress in human cardiovascular adipose tissue
The study found that adding serotonin to fat tissue around the heart makes it produce more harmful chemicals, and adding a substance called methylene blue reduces that effect — which means serotonin’s damage is partly caused by a specific enzyme that methylene blue can block.