title: Larch arabinogalactan for dry eye protection and treatment of corneal lesions: investigations in rabbits.
abstract: OBJECTIVE
  The aim of the present study was to investigate the corneal protective and healing properties of arabinogalactan (AG), a natural polysaccharide present in conifers of the genus Larix (Larch). AG was tested in comparison with other two polysaccharides possessing well-established properties in the treatment of dry eye: tamarind seed polysaccharide and hyaluronic acid.
  
  
  METHODS
  The AG formulation was subjected to the following investigations: rheologic measurements; evaluation of mucoadhesive properties by rheologic interaction with mucin; ferning test; and in vivo evaluation on rabbits, including treatment of an experimental dry eye; evaluation of the preocular retention; and evaluation of healing rate of experimental corneal wound.
  
  
  RESULTS
  AG dispersions showed a newtonian nonviscous behavior, eta = 1.6 mPa . s for 10% w/w solution; it possessed good mucoadhesive properties useful for retention on the eye surface. In fact, a prolonged time of residence in rabbit eyes was ascertained using fluorescein-labeled AG. Five percent (5.0%) w/w AG exerted a good protective effect against the appearance of corneal dry spots. It also reduced significantly the healing time of an experimental corneal lesion since 27 h after the first treatment.
  
  
  CONCLUSIONS
  These findings suggest that AG may be a potential therapeutic product for dry eye protection and for the treatment of corneal wounds.
authors.affiliation: Department of Bioorganic Chemistry and Biopharmaceutics, University of Pisa, Pisa, Italy. burgal@farm.unipi.it
authors.forename: Susi
authors.initials: S
authors.lastname: Burgalassi
authors.forename: Nadia
authors.initials: N
authors.lastname: Nicosia
authors.forename: Daniela
authors.initials: D
authors.lastname: Monti
authors.forename: Giulia
authors.initials: G
authors.lastname: Falcone
authors.forename: Enrico
authors.initials: E
authors.lastname: Boldrini
authors.forename: Patrizia
authors.initials: P
authors.lastname: Chetoni
mesh_terms: D000818:Animals; D003316:Corneal Diseases / Q000188:drug therapy*; D004195:Disease Models, Animal; D004337:Drug Carriers / Q000737:chemistry / Q000627:therapeutic use; D004353:Drug Evaluation, Preclinical; D004361:Drug Tolerance; D015352:Dry Eye Syndromes / Q000517:prevention & control*; D005685:Galactans / Q000737:chemistry / Q000627:therapeutic use*; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry / Q000627:therapeutic use; D028221:Larix / Q000737:chemistry*; D008297:Male; D010316:Particle Size; D011134:Polysaccharides / Q000737:chemistry / Q000627:therapeutic use; D011817:Rabbits; D012212:Rheology; D012995:Solubility; D013499:Surface Properties; D029861:Tamarindus / Q000737:chemistry; D013997:Time Factors; D014783:Viscosity
chemical_list: D004337:Drug Carriers; D005685:Galactans; D011134:Polysaccharides; D006820:Hyaluronic Acid; C005653:arabinogalactan