c.i. basic blue 9

Methylene Blue trihydrate (Basic blue 9) is a compound consisting of dark green crystals or crystalline powder, having a bronze-like luster. Solutions in water or alcohol have a deep blue color. Methylene Blue trihydrate is used as a bacteriologic stain and as an indicator. It inhibits soluble guanylyl cyclase and has been used to treat cyanide poisoning and to lower levels of methemoglobin. It also inhibits tau filament formation (IC50: 1.9μM).

Methylene Blue (Basic Blue 9) hydrate functions as an inhibitor of guanylyl cyclase (sGC), monoamine oxidase A (MAO-A), and NO synthase (NOS). This compound, known for its vasopressor activity, is widely utilized as a dye in various medical procedures. It operates via the nitric oxide synthase/guanylate cyclase signaling pathway to diminish prepulse inhibition and possesses the capacity to cross the blood-brain barrier. Methylene Blue hydrate acts as a REDOX cycling compound and inhibits Tau protein aggregation. Moreover, it is effective in reducing cerebral edema, damping microglial activation, and alleviating neuroinflammation, demonstrating its multifaceted therapeutic potential [1] [2] [3].

Methylene Blue (Tetramethylthionine chloride) (IC50 of 1.9 μM) inhibits tau filament formation. And it inhibits soluble guanylyl cyclase. It is also used as a dye in chromoendoscopy.