This study aimed to evaluate the potential of hederacoside C, an active compound isolated from Hedera helix, which has been used for managing inflammatory respiratory diseases, in attenuating epidermal growth factor (EGF)-induced airway MUC5AC mucin gene expression. Human pulmonary mucoepidermoid NCI-H292 cells were pretreated with hederacoside C for 30 min and subsequently stimulated with EGF for 24 h. The study also examined the effect of hederacoside C on the EGF-induced mitogenactivated protein kinase (MAPK) signaling pathway. The results showed that hederacoside C inhibited MUC5AC mucin mRNA expression and the production of mucous glycoproteins by suppressing the phosphorylation of the EGF receptor (EGFR), as well as the phosphorylation of MAPK/extracellular signal-regulated kinase (ERK) 1/2 (MEK1/2), p38 MAPK, ERK 1/2 (p44/42), and the nuclear expression of specificity protein-1 (Sp1). These findings suggest that hederacoside C has the potential to reduce EGFinduced mucin gene expression by inhibiting the EGFR-MAPK-Sp1 signaling pathway in NCI-H292 cells.

This study aimed to evaluate the potential of hederacoside C, an active compound isolated from Hedera helix, which has been used for managing inflammatory respiratory diseases, in attenuating epidermal growth factor (EGF)-induced airway MUC5AC mucin gene expression. Human pulmonary mucoepidermoid NCI-H292 cells were pretreated with hederacoside C for 30 min and subsequently stimulated with EGF for 24 h. The study also examined the effect of hederacoside C on the EGF-induced mitogenactivated protein kinase (MAPK) signaling pathway. The results showed that hederacoside C inhibited MUC5AC mucin mRNA expression and the production of mucous glycoproteins by suppressing the phosphorylation of the EGF receptor (EGFR), as well as the phosphorylation of MAPK/extracellular signal-regulated kinase (ERK) 1/2 (MEK1/2), p38 MAPK, ERK 1/2 (p44/42), and the nuclear expression of specificity protein-1 (Sp1). These findings suggest that hederacoside C has the potential to reduce EGFinduced mucin gene expression by inhibiting the EGFR-MAPK-Sp1 signaling pathway in NCI-H292 cells.

This study aimed to evaluate the potential of hederacoside C, an active compound isolated from Hedera helix, which has been used for managing inflammatory respiratory diseases, in attenuating epidermal growth factor (EGF)-induced airway MUC5AC mucin gene expression. Human pulmonary mucoepidermoid NCI-H292 cells were pretreated with hederacoside C for 30 min and subsequently stimulated with EGF for 24 h. The study also examined the effect of hederacoside C on the EGF-induced mitogenactivated protein kinase (MAPK) signaling pathway. The results showed that hederacoside C inhibited MUC5AC mucin mRNA expression and the production of mucous glycoproteins by suppressing the phosphorylation of the EGF receptor (EGFR), as well as the phosphorylation of MAPK/extracellular signal-regulated kinase (ERK) 1/2 (MEK1/2), p38 MAPK, ERK 1/2 (p44/42), and the nuclear expression of specificity protein-1 (Sp1). These findings suggest that hederacoside C has the potential to reduce EGFinduced mucin gene expression by inhibiting the EGFR-MAPK-Sp1 signaling pathway in NCI-H292 cells.

In this study, we investigated the effects of the flavonoid galangin on the expression of the mucin 5AC (MUC5AC) gene in airway cells. Human pulmonary epithelial NCI-H292 cells were pretreated with galangin for 30 min and then stimulated with phorbol 12-myristate 13-acetate (PMA) for 24 h. We also examined the effects of galangin on the PMA-induced nuclear factor-κB (NF-κB) signaling pathway. Galangin inhibited the production of glycoproteins and the expression of MUC5AC mRNA induced by PMA via prevention of NF-κB inhibitor α degradation and NF-κB p65 nuclear translocation. These findings indicated that galangin suppressed mucin gene expression by modulating the NF-κB signaling pathway in human pulmonary epithelial cells.

In this study, we investigated the effects of the flavonoid galangin on the expression of the mucin 5AC (MUC5AC) gene in airway cells. Human pulmonary epithelial NCI-H292 cells were pretreated with galangin for 30 min and then stimulated with phorbol 12-myristate 13-acetate (PMA) for 24 h. We also examined the effects of galangin on the PMA-induced nuclear factor-κB (NF-κB) signaling pathway. Galangin inhibited the production of glycoproteins and the expression of MUC5AC mRNA induced by PMA via prevention of NF-κB inhibitor α degradation and NF-κB p65 nuclear translocation. These findings indicated that galangin suppressed mucin gene expression by modulating the NF-κB signaling pathway in human pulmonary epithelial cells.

In this study, we investigated the effects of the flavonoid galangin on the expression of the mucin 5AC (MUC5AC) gene in airway cells. Human pulmonary epithelial NCI-H292 cells were pretreated with galangin for 30 min and then stimulated with phorbol 12-myristate 13-acetate (PMA) for 24 h. We also examined the effects of galangin on the PMA-induced nuclear factor-κB (NF-κB) signaling pathway. Galangin inhibited the production of glycoproteins and the expression of MUC5AC mRNA induced by PMA via prevention of NF-κB inhibitor α degradation and NF-κB p65 nuclear translocation. These findings indicated that galangin suppressed mucin gene expression by modulating the NF-κB signaling pathway in human pulmonary epithelial cells.

In this study, the potential effects of pyronaridine, an antimalarial agent, on airway MUC5AC mucin gene expression were investigated. The human pulmonary epithelial NCI-H292 cells were pretreated with pyronaridine for 30 min and then stimulated with phorbol 12-myristate 13-acetate (PMA) for 24 h. The effect of pyronaridine on the PMA-induced nuclear factor kappa B (NF-κB) signaling pathway was also examined. Pyronaridine inhibited glycoprotein production and mRNA expression of MUC5AC mucins induced by PMA through the inhibition of degradation of inhibitory kappa Bα and NF-κB p65 nuclear translocation. These results suggest that pyronaridine suppresses gene expression of mucin through regulation of the NF-κB signaling pathway in human pulmonary epithelial cells.

In this study, artesunate, an antimalarial agent, was investigated for its potential effect on the gene expression of airway MUC5AC mucin. The human pulmonary epithelial NCI-H292 cells were pretreated with artesunate for 30 min and then stimulated with phorbol 12-myristate 13-acetate (PMA), for the following 24 h. The effect of artesunate on PMA-induced nuclear factor kappa B (NFkB) signaling pathway was also examined. Artesunate inhibited the glycoprotein production and mRNA expression of MUC5AC mucins, induced by PMA through the inhibition of degradation of inhibitory kappa Bα (IkBα) and NF-kB p65 nuclear translocation.These results suggest artesunate suppresses the gene expression of mucin through regulation of NF-kB signaling pathway, in human pulmonary epithelial cells.

Idiopathic pulmonary fibrosis (IPF) can be defined as a progressive chronic pulmonary disease showing scarring in the lung parenchyma, thereby resulting in increase in mortality and decrease in the quality of life. The pathophysiologic mechanism of fibrosis in IPF is still unclear. Repetitive microinjuries to alveolar epithelium with genetical predisposition and an abnormal restorative reaction accompanied by excessive deposition of collagens are involved in the pathogenesis. Although the two FDA-approved drugs, pirfenidone and nintedanib, are under use for retarding the decline in lung function of patients suffered from IPF, they are not able to improve the survival rate or quality of life. Therefore, a novel therapeutic agent acting on the major steps of the pathogenesis of disease and/or, at least, managing the clinical symptoms of IPF should be developed for the effective regulation of this incurable disease. In the present review, we tried to find a potential of managing the clinical symptoms of IPF by natural products derived from medicinal plants used for controlling the pulmonary inflammatory diseases in traditional Asian medicine. A multitude of natural products have been reported to exert an antifibrotic effect in vitro and in vivo through acting on the epithelial-mesenchymal transition pathway, transforming growth factor (TGF)-β-induced intracellular signaling, and the deposition of extracellular matrix. However, clinical antifibrotic efficacy of these natural products on IPF have not been elucidated yet. Thus, those effects should be proven by further examinations including the randomized clinical trials, in order to develop the ideal and optimal candidate for the therapeutics of IPF.

Betulin is a triterpenoid natural product contained in several medicinal plants including Betulae Cortex. These medicinal plants have been used for controlling diverse inflammatory diseases in folk medicine and betulin showed anti-inflammatory, antioxidative, and anticancer activities. In this study, we tried to examine whether betulin exerts a regulative effect on the gene expression of MUC5AC mucin under the status simulating a pulmonary inflammation, in human airway epithelial cells. Confluent NCI-H292 cells were pretreated with betulin for 30 min and then stimulated with phorbol 12-myristate 13-acetate (PMA) for 24 h or the indicated periods. The MUC5AC mucin mRNA expression and mucin glycoprotein production were measured by reverse transcription -polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. To elucidate the action mechanism of betulin, effect of betulin on PMA-induced nuclear factor kappa B (NF-kB) signaling pathway was also investigated by western blot analysis. The results were as follows: 1) Betulin significantly suppressed the production of MUC5AC mucin glycoprotein and down-regulated MUC5AC mRNA expression induced by PMA in NCI-H292 cells. 2) Betulin inhibited NF-κB activation stimulated by PMA. Suppression of inhibitory kappa B kinase (IKK) by betulin led to the inhibition of the phosphorylation and degradation of inhibitory kappa B alpha (IκBα), and the nuclear translocation of NF-κB p65. This, in turn, led to the down-regulation of MUC5AC glycoprotein production in NCI-H292 cells. These results suggest betulin inhibits the gene expression of mucin through regulation of NF-kB signaling pathway, in human airway epithelial cells.