Figure 1.

Cilantro extract differentially activates homomeric KCNQ channels All error bars indicate sem. A) Image of the fresh cilantro (Coriander sativum) used in this study. B) Topological representation of a Kv channel showing 2 of the 4 subunits that comprise a channel. C) Extracellular view of the chimeric KCNQ1/KCNQ3 structural model to highlight the anticonvulsant binding pocket (red, KCNQ3-W265). D) Left, mean TEVC current traces for water-injected Xenopus oocytes in the absence (control) or presence of 1% cilantro extract (n = 5). Dashed line here and throughout indicates the 0 current level. Upper inset: the voltage protocol used here and throughout the study unless otherwise indicated. Center: mean tail current for oocytes on left (n = 5). Right: scatter plot of resting membrane potential (E_M) of water-injected oocytes in the absence (Control) or presence of cilantro extract (n = 5). Statistical analyses by 2-way ANOVA. E) Left: mean TEVC current traces for Xenopus oocytes expressing the KCNQ homomers indicated in the absence (control) or presence of 1% cilantro extract (n = 5–6). Arrow indicates time point at which KCNQ tail currents are measured throughout this study. F) Mean tail current (left) and normalized tail current (G/G_max) (right) vs. prepulse voltage relationships for the traces as in the previous panel (n = 5–6). G) Effects of 1% cilantro extract on E_M of unclamped oocytes expressing the channels as in E (n = 5–6). Statistical analyses by 2-way ANOVA. H) Current-fold increase vs. voltage for the KCNQ isoforms indicated, induced by 1% cilantro extract (n = 5–6). I) Scatter plot showing mean ΔV_{0.5 activation} induced by 1% cilantro extract for the KCNQ isoforms indicated (n = 5–6). Statistical analysis by 2-way ANOVA corrected for multiple comparisons.