Rebamipide promotes lacrimal duct epithelial cell survival via protecting barrier function

Nasolacrimal duct obstruction (NLDO) is thought to be due to inflammation and fibrosis of lacrimal duct epithelial cells (LDECs). Here we investigated the effect of rebamipide, a drug that is used for the protection of the mucosa and the treatment of gastritis and gastroduodenal ulcers, on LDECs, both in vitro and in vivo. In this study, LDECs were cultured from rabbit lacrimal duct tissues, and the barrier function of LEDCs was examined in vitro via transepithelial electrical resistance (TER) measurement, with or without interleukin (IL)-6 and/or rebamipide. For the in vivo examination, benzalkonium chloride (BAC) was injected into the rabbit lacrimal ducts, followed by the application of rebamipide or a placebo vehicle alone. The results of the in vitro examination revealed a significant decrease in TER in the group treated with IL-6 alone compared with the placebo-vehicle group (p < 0.05) and the group treated with IL-6 and rebamipide (p < 0.01). The results of the in vivo examination revealed that the infiltration of neutrophils under the basement membrane and the disruption of tight junction proteins with BAC injection and rebamipide attenuates the disturbance of tissue construction. These results suggest that rebamipide protects LDECs via an anti-inflammatory effect and preserves the barrier function of those cells.