BACKGROUND: We investigated whether prunetin significantly affects tumor necrosis factor-alpha (TNF-alpha)-induced MUC5AC mucin gene expression, production, inhibitory kappa B (IkappaB) degradation and nuclear factor kappa B (NF-kappaB) p65 translocation in human airway epithelial cells. METHODS: Confluent NCI-H292 cells were pretreated with prunetin for 30 minutes and then stimulated with TNF-alpha for 24 hours or the indicated periods. MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The effect of prunetin on TNF-alpha-induced degradation of IkappaB and translocation of NF-kappaB p65 was investigated by western blot analysis. RESULTS: We found that incubation of NCI-H292 cells with prunetin significantly inhibited mucin production and down-regulated the MUC5AC gene expression induced by TNF-alpha. Prunetin inhibited TNF-alpha-induced degradation of IkappaB and translocation of NF-kappaB p65. CONCLUSION: This result suggests that prunetin inhibits the NF-kappaB signaling pathway, which may explain its role in the inhibition of MUC5AC mucin gene expression and production regulated by the NF-kappaB signaling pathway.
Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Epithelial Cells* ; Gene Expression* ; Humans* ; Isoflavones ; Mucin 5AC ; Mucins* ; NF-kappa B* ; Polymerase Chain Reaction ; Reverse Transcription ; Tumor Necrosis Factor-alpha

BACKGROUND: We investigated whether chrysin affected MUC5AC mucin production and gene expression induced by phorbol ester (phorbol 12-myristate 13-acetate, PMA) or epidermal growth factor (EGF) from human airway epithelial cells. METHODS: Confluent NCI-H292 cells were pretreated with varying concentrations of chrysin for 30 minutes, and were then stimulated with PMA and EGF for 24 hours, respectively. MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: Concentrations of 10microM and 100microM chrysin were found to inhibit the production of MUC5AC mucin protein induced by PMA; A concentration of 100microM chrysin also inhibited the production of MUC5AC mucin protein induced by EGF; 100microM chrysin inhibited the expression of MUC5AC mucin gene induced by PMA or EGF. The cytotoxicity of chrysin was checked by lactate dehydrogenase assay, and there was no cytotoxic effect observed for chrysin. CONCLUSION: These results suggest that chrysin can inhibit mucin gene expression and the production of mucin protein by directly acting on airway epithelial cells.
Epidermal Growth Factor ; Epithelial Cells ; Flavonoids ; Gene Expression ; Humans ; L-Lactate Dehydrogenase ; Mucins ; Phorbols ; Polymerase Chain Reaction ; Reverse Transcription

BACKGROUND: We investigated whether wogonin and apigenin significantly affect the epidermal growth factor receptor (EGFR) signaling pathway involved in MUC5AC mucin gene expression, and production from cultured airway epithelial cells; this was based on our previous report that apigenin and wogonin suppressed MUC5AC mucin gene expression and production from human airway epithelial cells. METHODS: Confluent NCI-H292 cells were pretreated with wogonin or apigenin for 15 minutes or 24 hours and then stimulated with epidermal growth factor (EGF) for 24 hours or the indicated periods. RESULTS: We found that incubation of NCI-H292 cells with wogonin or apigenin inhibited the phosphorylation of EGFR. The downstream signals of EGFR such as phosphorylation of MEK1/2 and ERK1/2 were also inhibited by wogonin or apigenin. CONCLUSION: The results suggest that wogonin and apigenin inhibits EGFR signaling pathway, which may explain how they inhibit MUC5AC mucin gene expression and production induced by EGF.
Apigenin* ; Epidermal Growth Factor* ; Epithelial Cells* ; Gene Expression* ; Humans ; Mucins* ; Phosphorylation ; Receptor, Epidermal Growth Factor*