Studies of coronavirus disease 2019 (COVID-19) as a current global health problem shown the
initial plasma levels of most pro-inflammatory cytokines increased during the infection, which
leads to patient countless complications. Previous studies also demonstrated that the
metronidazole (MTZ) administration reduced related cytokines and improved treatment in
patients. However, the effect of this drug on cytokines has not been determined. In the present
study, the interaction of MTZ with cytokines was investigated using molecular docking as one of
the principal methods in drug discovery and design. According to the obtained results, the IL12-metronidazole complex is more stable than other cytokines, and an increase in the surface and
volume leads to prevent to bind to receptors. Moreover, ligand-based virtual screening of several
libraries showed metronidazole phosphate, metronidazole benzoate, 1-[1-(2-Hydroxyethyl)-5-
nitroimidazol-2-yl]-N-methylmethanimine oxide, acyclovir, and tetrahydrobiopterin (THB or
BH4) like MTZ by changing the surface and volume prevents binding IL-12 to the receptor.
Finally, the inhibition of the active sites of IL-12 occurred by modifying the position of the
methyl and hydroxyl functional groups in MTZ. <br>
