Dehydration of airway surface liquid (ASL) disrupts normal mucociliary clearance in sinonasal epithelium leading to chronic rhinosinusitis. Abnormal chloride (Cl−) transport is one mechanism that contributes to this disorder, as demonstrated by the disease cystic fibrosis. Identifying safe compounds that stimulate transepithelial Cl− transport is critical to improving hydration of the ASL and promoting mucociliary transport. Sinupret (Bionorica, LLC, San Clemente, CA), a combination of naturally occurring bioflavonoids, is a widely used treatment for respiratory ailments in Europe. However, the effects of Sinupret on target respiratory epithelium have yet to be fully investigated. The present study evaluated the mechanisms underlying this bioflavonoid therapeutic on transepithelial Cl− transport in respiratory epithelium.