Effects of chlorogenic acid, epicatechin gallate, and quercetin on mucin expression and secretion in the Caco‐2/HT29‐MTX cell model

Mucins are a family of large glycoproteins that represent the major structural components of the mucus and are encoded by 20 different mucin genes. Mucin expression can be modulated by different stimuli. In this study, we analyzed four mucins (MUC2, MUC3, MUC13, and MUC17) in coculture of Caco‐2/HT29‐MTX cells to demonstrate the variation in gene expression in the presence of antioxidant compounds like chlorogenic acid, epicatechin gallate, and quercetin (apple, tea, and coffee polyphenols, respectively). coculture of Caco‐2/HT29‐MTX cells was treated with polyphenols, and the expression of four mucins was determined by reverse‐transcriptase PCR. In addition, the secretion levels of MUC2 were established by enzyme‐linked immunoassay (ELISA) analysis. The results showed that each polyphenol compound induces different expression patterns of the mucin genes. Statistically significant up‐regulation of MUC17 was observed following incubation with epicatechin gallate and quercetin. ELISA results did not prove any significant differences in protein levels of MUC2 after treatment by the polyphenol compounds. The polyphenols considered in this study may influence mucin secretion and act on diverse salivary substrates to change the barrier properties of mucins for mucus secretion in different ways.