Effects of Cynaroside, Cynarin and Linarin on Secretion, Production and Gene Expression of Airway MUC5AC Mucin in NCI-H292 Cells

In this study, we investigated whether cynaroside, cynarin and linarin derived from Chrysanthemum indicum L. affect the secretion, production and gene expression of MUC5AC mucin in airway epithelial cells. Confluent NCI-H292 cells were pretreated with cynaroside, cynarin or linarin for 30 min and then stimulated with PMA (phorbol 12-myristate 13-acetate) for 24 h. The MUC5AC mucin gene expression, mucin protein production and secretion were measured by RT-PCR and ELISA, respectively. Effect of linarin on EGF (epidermal growth factor) - or TNF-${\alpha}$ (tumor necrosis factor-${\alpha}$)-induced MUC5AC mucin gene expression and mucin protein production was also examined. The results were as follows: (1) Cynaroside and cynarin did not significantly affect PMA-induced MUC5AC mucin secretion from NCI-H292 cells. However, linarin decreased MUC5AC mucin secretion; (2) Cynaroside did not affect PMA-induced MUC5AC mucin production and gene expresion from NCI-H292 cells. However, cynarin and linarin inhibited the production and gene expression of MUC5AC mucin; (3) Linarin also inhibited the production and gene expression of MUC5AC mucin induced by EGF- or TNF-${\alpha}$ from NCI-H292 cells. These results suggest that linarin can regulate the gene expression, production and secretion of mucin, by directly acting on airway epithelial cells.