OM-LV20 inhibited phosphorylation of MAPK signaling pathway and increased levels of TPH1 and PAC1R in CTX-TNA2 cells under H2O2stimulation.A, representative Western blots of MAPK, TPH1, and PAC1R protein levels in CTX-TNA2 cells. B, OM-LV20 significantly promoted mRNA level of PAC1R. C–F, histogram of PAC1R, TPH1, p-JNK, and p-p38 protein expression, respectively. Data are means ± SEM. n = 3, ∗p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001.