WHAT IS METHYLENE BLUE (MB)?

At the end of the 19th Century, the prosperity of the textile industry gave great impetus to the search for dyes. In 1876, methylene blue was synthesized as a dye for cotton.
Although not proving very suitable for the textile industry, scientists of the time such as Robert Koch and Paul Ehrlich realized that it was able to selectively dye and inactivate various microbial species.

Following this discovery, it was thought to use MB to treat tropical diseases, and in 1891 Ehrlich proved that it was effective in the treatment of malaria.

Thus, MB was the first synthetic compound in the history of medicine to be used as an antiseptic, long before sulfonamides and penicillin.

It is the progenitor of phenothiazines, a class of substances obtained by modifying the MB molecule and initially used as insecticides and pesticides, and for subsequent modifications as antipsychotic drugs: the first for the treatment of schizophrenia.

From a toxicological point of view, MB has an enviable safety record: at recommended doses, it is almost side effects-free.

A fascinating molecule, for the variety of possible applications, such as:

1. First-line treatment of methemoglobinemia, a life-threatening disease which can be congenital or acquired following the ingestion of drugs or chemicals, or well water rich in nitrates, or by ingestion of cyanide. These substances oxidize the hemoglobin contained in red blood cells which is no longer able to bind oxygen to be transported to the tissues (methemoglobin), and MB restores its functionality.
2. Antiseptic activity, enhanced by light, and for this property it is added to plasma for transfusions and exposed to UV rays.
3. Successful use, via the venous route, in septic and vasoplegic shock.
4. Treatment of malaria in cases of resistance to other treatments
5. More recent applications in: Alzheimer’s disease, Psychosis, Neuroprotection, Intractable itching.