Niflumic acid reduces histamine-induced interleukin-6 and -8 expression in human conjunctival epithelial cells

Background/Aims: Histamine remains the main mediator of allergic conjunctivitis and induces interleukin (IL)-6 and IL-8 production in human conjunctival epithelial cells (HCEC). The purpose of the present study was to determine whether histamine induced IL-6 and IL-8 expression in HCEC, and to describe the relationship between human calcium-activated chloride channel (hCLCA) 1 activity and IL-6 and IL-8 expression. Methods: HCEC were isolated from human conjunctiva and cultured at an air-liquid interface. IL-6 and IL-8 mRNA expression was examined by real-time PCR, and IL-6 and IL-8 secretion was measured by ELISA after stimulation of HCEC with histamine. Results: Histamine upregulated IL-6 and IL-8 expression and IL-6 and IL-8 secretion in a dose-dependent manner in HCEC. Niflumic acid (NFA), an hCLCA blocker, reduced histamine-induced IL-6 and IL-8 expression. Conclusion: Histamine-induced IL-6 and IL-8 production could be attenuated by NFA, an hCLCA blocker.