Figure 2.

Effects of hypericin on the whole-cell peak Na⁺ currents. (A) Current traces showing effect of extracellularly applied 1.0 µM hypericin on whole-cell Na⁺ currents (representative of seven cells). The currents was evoked by voltage steps from −100 mV to +20 mV in 10 mV increments for 12 ms. (B) Summary data of the ratio (I/I₀) of the whole-cell Na⁺ peak currents before (I₀) and after (I) application of different concentrations of hypericin. (C) Summary data of the ratio (τ/τ_o) of the decay time constant of Na⁺ current evoked at −30 mV before (τ₀) and after (τ) application of different concentrations of hypericin. The decay time constant of Na⁺ current was derived by fitting a single exponential. There are no significant differences between control and different hypericin concentration groups in both (B) and (C) (P > 0.05, one-way anova).