The effect of quercetin on human neutrophil elastase‐induced mucin5AC expression in human airway epithelial cells

► First study on the protective effect of quercetin against HNE-induced MUC5AC overexpression in HBE16 cells. ► ERK1/2 but not P38 and JNK were involved in quercetin protection against HNE-induced MUC5AC overexpression. ► Involvements of PKC and EGFR pathways in the protective effect of quercetin against HNE-induced MUC5AC overexpression.