Carbenoxolone and triterpenoids inhibited mucin secretion from airway epithelial cells

This study investigated whether carbenoxolone, oleanolic acid and ursolic acid affect ATP-induced mucin secretion from cultured airway epithelial cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using H-3-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on H-3-mucin secretion. The possible cytotoxicity of each agent was investigated with a lactate dehydrogenase assay. The results were as follows: (1) carbenoxolone, oleanolic acid and ursolic acid significantly inhibited the secretion of airway mucin induced by ATP; (2) none of the compounds showed significant cytotoxicity at any concentration. This result suggests that carbenoxolone, oleanolic acid and ursolic acid can regulate 'mucin secretion induced by ATP' - a phenomenon simulating mucus overproduction from inflamed airway epithelial cells - by directly acting on airway mucin-secreting cells. Copyright (c) 2007 John Wiley & Sons, Ltd.