Effect of Hyperoside on Phorbol Ester-induced Gene Expression of Mucin and NF-κB Signaling in Cultured Human Airway Epithelial Cells

We investigated whether hyperoside, an anti-inflammatory natural product, significantly affects phorbol 12- myristate 13-acetate (PMA)-induced airway expression of MUC5AC encoded mucin. Confluent NCI-H292 cells were pretreated with hyperoside for 30 min, then stimulated with PMA for 24 h or the indicated periods. MUC5AC mucin mRNA expression was measured by RT-PCR. MUC5AC mucin protein expression was quantitated by ELISA. To elucidate the mechanism of hyperoside action, we investigated the effect of hyperoside on PMA-induced NF-κB signaling by western blot analysis. The results were as follows: (1) Hyperoside significantly inhibited MUC5AC mucin protein production and down-regulated MUC5AC mucin mRNA expression; (2) Hyperoside inhibited PMA-induced activation (phosphorylation) of inhibitory kappa B kinase (IKK), thereby inhibiting phosphorylation and degradation of inhibitory kappa Bα (IκBα); (3) Hyperoside inhibited PMA-induced nuclear translocation of nuclear factor kappa B (NF-κB) p65, thereby down-regulating MUC5AC mucin gene expression in NCI-H292 cells. These results suggest that hyperoside can regulate mucin gene expression by airway epithelial cells through regulation of the NF-κB signaling pathway.