Rebamipide Increases Mucin-Like Substance Contents and Periodic Acid Schiff Reagent-Positive Cells Density in Normal Rabbits

Abstract

The effects of rebamipide on the number of periodic acid Schiff reagent (PAS)-positive cells in the conjunctiva, the mucin content in the cornea and conjunctiva of normal rabbits, and desiccation-induced corneal damage in vivo were examined. Rebamipide (0.1%-3%) was applied 6 times a day for 14 days, and the PAS-positive cell count in the bulbar conjunctiva was measured by impression cytology. The amount of conjunctival and corneal mucin-like substances was measured by Alcian blue binding. The corneal damage model was created by desiccation from air flow at room temperature. The level of corneal damage was determined by scoring the area stained with rose bengal and fluorescein dye. Rebamipide increased the number of PAS-positive cells in the conjunctiva when instilled at concentrations of 0.3% or higher, and 1% rebamipide increased the amount of mucin-like substances of the conjunctiva and cornea. Moreover, 1% rebamipide was also found to lower the rose bengal scores of the cornea in the corneal damage model by desiccation. Rebamipide is a possible candidate drug for treatment of cornea and conjunctival epithelial damage due to its mucin-like substance increasing action, for instance, in the treatment of dry eye disease.