Methisazone (Marboran) is a compound of the class of N-aminomethyl-isatin-beta-thiosemicarbizones. It acts as an antiviral agent, working via inhibiting mRNA and protein synthesis. In the early 1950s, Methisazone has been found to have activity against vaccinia and variola viruses. Thus, Methisazone can be used for kinds of antiviral research, such as orthopoxvirus infections, keratitis caused by herpes virus, and prevention of smallpox virus infection. Following recent studies, Methisazone may become an anti-COVID-19 agent.

Here, we will illustrate in vivo and in vitro activities of Methisazone.

Methisazone (0.2 ml of 12.5, 25, 50, 100, and 200 μg) suppresses the growth of plaque in CV-1 cells tissue infected with monkeypox and vaccinia viruses. Additionally, In vivo experiments exhibits that, this agent can temporarily prolong the life of mice infected monkey pox virus (MPV).

Methisazone (5~40 μM) inhibits the multiplication of various types of adenovirus, including 3, 7, 9, 11, 14, 16, 17, 21, 28 types and SV15. Under single-cycle conditions, this agent (30 μM) even completely inhibits adenovirus 11 proliferation after 13 hours of incubation.

Furthermore, In silico studies shows Methisazone interacts with 5R7Z, 5R80, and 5R81 SARS-CoV-2 enzymes with dock score values of -7.542, -6.829, and -6.928, respectively; and metal-modified (Ca-, Fe-, Mg-, Mn-, and Zn-) Methisazone display better binding energies for some SARS-CoV-2 proteins. It suggests that Methisazone may become a useful COVID-19 inhibitor.

Besides, under some circumstances, Methisazone can also cause a suppression of the hemopoietic colony-forming cell response to injection of adjuvant. It indicates that Methisazone is also an immunosuppressive agent.

In conclusion, Methisazone is a broad-spectrum antiviral agent, acting by inhibiting mRNA and protein synthesis.


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