• arabinogalactan
• mucins

Dry eye syndrome is associated with tear film deficiency, owing to either insufficient supply or excessive loss, and with anomalous tear composition. To counteract the symptoms of discomfort caused by tear deficiency, the use of artificial tears is needed. Artificial tears are usually characterized by an high viscosity, which should increase their residence on the ocular surface. However, the high viscosity may lead up to inconveniences, such as sticky feeling and solidification. In this regard, a strategy to antagonize the discomfort of dry eye is the use of a low viscosity polysaccharidic molecule that may endure on the ocular surface without unpleasant disadvantages. Arabinogalactan (AG), a natural polysaccharide present in conifers of the genus Larix (Larch), is a no-viscous polymer which was recently shown to be a potential therapeutic product for dry eye protection and for the treatment of corneal wounds. The purpose of the investigation was the assessment of the mucoadhesive properties of purified AG by evaluating its ability to interact with mucins. Several methodological approaches were envisaged to develop a suitable and friendly assay to study the interaction between mucin and AG; however, only the gel filtration approach allowed to evaluate the interaction. The ability of AG to interact with highly representative mucins (MUC1, MUC2 and MUC3) of the ocular surface was investigated. A quantitative measurement of the interaction between AG and MUC1 came from “frontal” gel filtration chromatography. Moreover, two components of purified AG (AG-I and AG-II) were identified by gel filtration chromatography and their interaction with MUC1 was studied. The results denoted a potential use of AG as possible component of artificial tears; being capable to interact with mucins, it may remain on the ocular surface, prolonging the hydratation of the eye. Moreover, thanks to AG low viscosity, it may avoid the discomfort caused by the high viscosity eye drops, widely used in artificial tears.