In this study, we showed that osthole could inhibit the activation of TGF-β1/Smad2/3 and ERK1/2, p38, JNK MAPK signaling, thus contributing to the suppression of EMT and cell apoptosis in airway epithelium, respectively, in the experimental asthma model in vitro and in vivo. Here, MAPK3 is linked to asthma.