Fig. 2From: Petasin and isopetasin reduce CGRP release from trigeminal afferents indicating an inhibitory effect on TRPA1 and TRPV1 receptor channelsa Dura mater, rat. b Trigeminal ganglion, rat. Normalized CGRP release after pre-incubation with isopetasin concentrations (3, 10, 30 μg/mL, n = 6 each) compared to pre-incubation with ethanol (n = 12) for 1 h. Stimulation steps with 5 × 10− 4 M mustard oil (minutes 10–15) or 5 × 10− 7 M capsaicin (minutes 20–25); other steps with SIF incubation (minutes 5–10 and 15–20); *p < 0.05, **p < 0.01Back to article page