Fig. 4.

Eugenol inhibited ATP-induced P2X₃ currents in both P2X₃-expressing and P2X₃/TRPV1-coexpressing HEK293 cells. (A) Representative current traces of 10 µM ATP-induced P2X₃ currents under control (Aa and Ab, left), and eugenol (1 mM) (Aa and Ab, right) in both P2X₃-expressing (Aa) and P2X₃/TRPV1-coexpressing (Ab) HEK293 cells. (B) The summary of the inhibition of ATP-induced P2X₃ currents in both P2X₃-expressing (Aa) and P2X₃/TRPV1-coexpressing (Ab) HEK293 cells. The amplitude of second (C₂) and third currents (C₃) was normalized compared to the first one (C₁). Eugenol-induced inhibition in P2X₃-expressing cells (n=13) was similar to that obtained in P2X₃/TRPV1-coexpressing cells (n=12) (mean±SEM, p>0.05). Black points indicate the time point of ATP application.