Fisetin modulated mEAG1 currents. (A) Representative current traces of mEAG1 channels recoded in the inside-out patch configuration in the absence (black), presence (red), and after washout (gray) of 30 µM fisetin. (B) The averaged conductance–voltage relationship of mEAG1 channels with 0 (black) or 30 µM fisetin (red) fit with a Boltzmann function (n = 6). (C) The tail current recorded at −120 mV after a voltage step to 50 mV in the absence (black) and presence (red) of 30 µM fisetin. Fits of these tail currents with single exponentials reported the time constant of deactivation: 5.3 ms before and 13.9 ms with 30 µM fisetin. (D) Plot of the ΔV_1/2 versus free fisetin concentration fit with a Hill equation (n = 5). The half-maximal concentration of fisetin was 3.5 ± 0.4 µM. (E) Plot of the time constant of mEAG1 deactivation versus free fisetin concentration, fit with a Hill equation (n = 5). The half-maximal concentration of fisetin was 6.6 ± 3.7 µM.