Figure 6

Osthole inhibited both histamine and capsaicin-induced calcium influx on the same DRG neurons.

(A) The traces of calcium influx induced by 100 μM histamine and 1 μM capsaicin (a) were inhibited by 1 μM osthole (b). (B) The response curves of histamine and capsaicine were added respectively in the normal perfusion and the vehicle (1% DMSO) solution. (C,D) The normalized fluorescence intensities of osthole to inhibit histamine (C) and capsaicine (D)-induced calcium influx are 29 ± 6% (n = 16, **p < 0.01) and 23 ± 16% (n = 16, ***p < 0.001), respectively. (E) Osthole (IC50 ≈ 0.41 μM) and AMG9810 (IC50 ≈ 0.1 μM) were able to significantly inhibit the response induced by histamine. However, the inhibitory effects between osthole and AMG9810 to histamine-induced responses were not significantly different.