In order to assess whether the protective effect is related to the inhibition of the MAO-A or due to another mechanism, the effect of Brofaromine is determined on the activity of MAO-A in cultured cortical cells. The cultured cortical cells have significant MAO-A activity. Brofaromine inhibits the enzyme in a concentration-dependent manner (IC50: 0.19?μM). Hill coefficient is 0.96. The enzyme is almost completely inhibited at 10?μM. Brofaromine inhibits MAO-A activity of our cultured cortical cells in a concentration-dependent manner. The IC50 range of Brofaromine is 0.01?μM to 0.1?μM.