Methylene Blue

Methylene blue (Basic Blue 9) is a guanylyl cyclase (sGC), monoamine oxidase A (MAO-A) and NO synthase (NOS) inhibitor. Methylene blue is a vasopressor and is often used as a dye in several medical procedures. Methylene blue through the nitric oxide syntase/guanylate cyclase signalling pathway to reduce prepulse inhibition. Methylene blue is a REDOX cycling compound and able to cross the blood-brain barrier. Methylene blue is a Tau aggregation inhibitor. Methylene Blue is a photosensitizer and redox agent. Methylene blue reduces cerebral edema, attenuated microglial activation and reduced neuroinflammation^[1][2][3][4]. IC50 & Target:Guanylyl cyclase (sGC)^[1].
Monoamine oxidase A (MAO-A)^[1].
NO synthase (NOS)^[1] In Vitro:Methylene blue (Basic Blue 9) (4.5 μM; BV2 microglia) alters the immune profile of LPS-activated BV2 microglia and decreases the level of CD14, IL-1β, TNF-α, and CCL2 mRNA^[3].
1. Sample treatment:
1.1 For paraffin sections: dewax and rehydrate as usual.
1.2 For frozen sections: distilled water for 2 min.
1.3 For cultured cells: Fix with 4% paraformaldehyde. Wash with distilled water for 2 min. Replace with fresh distilled water and wash for another 2 min.
2. Methylene blue staining
2.1 Stain with 0.1% Methylene blue for 2 min.
2.2 Wash thoroughly with distilled water, observe and take photos.
2.3 Staining results:
Tissue or cells: blue
In Vivo:Methylene blue (Basic Blue 9) (50 and 100 mg/kg; i.p.; once, for 25 min; male NMRI mice) reduces absent prepulse inhibition^[1].
Methylene blue (Basic Blue 9) (20 and 40 mg/kg; p.o.; daily, for 6 months; CaMKIIα-tTA transactivator mice) preserves cognition in mice expressing full-length pro-aggregant human Tau^[2].
Methylene blue (Basic Blue 9) (2 mg/kg; i.v.; once, for 1 d; TBI-treated male BALB/c mice) reduces TBI-induced edema and neuroinflammation and reduces acute depression-like behavior^[3].
Methylene blue (Basic Blue 9) (2 mg/kg; i.v.; once, for 1 d; TBI-treated male BALB/c mice) reduces the percentage of inflammatory factor^[3].